You searched for subject:(Level set method).
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1.
Ovsyannikov, Andrey.
Nouveau développement de la méthode Level Set sur la base d'une équation modifiée de suivi d'interface : Further development of Level Set method : modified level set equation and its numerical assessment.
Degree: Docteur es, Mécanique des fluides, 2013, Ecully, Ecole centrale de Lyon
URL: http://www.theses.fr/2013ECDL0013 
► Pas de résumé
The level set method was introduced by Osher & Sethian (1988) as a general technique to capture moving interfaces. It has been…
(more)
▼ Pas de résumé
The level set method was introduced by Osher & Sethian (1988) as a general technique to capture moving interfaces. It has been used to study crystal growth, to simulate water and fire for computer graphics applications, to study two-phase flows and in many other fields. The wellknown problem of the level set method is the following: if the flow velocity is not constant, the level set scalar may become strongly distorted. Thus, the numerical integration may suffer from loss of accuracy. In level set methods, this problem is remedied by the reinitialization procedure, i.e. by reconstruction of the level set function in a way to satisfy the eikonal equation. We propose an alternative approach. We modify directly the level set equation by embedding a source term. The exact expression of this term is such that the eikonal equation is automatically satisfied. Furthermore on the interface, this term is equal to zero. In the meantime, the advantage of our approach is this: the exact expression of the source term allows for the possibility of derivation of its local approximate forms, of first-and-higher order accuracy. Compared to the extension velocity method, this may open the simplifications in realization of level set methods. Compared to the standard approach with the reinitialization procedure, this may give the economies in the number of level set re-initializations, and also, due to reduced number of reinitializations, one may expect an improvement in resolution of zero-set level. Hence, the objective of the present dissertation is to describe and to assess this approach in different test cases.
Advisors/Committee Members: Gorokhovski, Mikhael (thesis director), Sabel'Nikov, Vladimir (thesis director).
Subjects/Keywords: Méthode Level Set; Suivi d'interface; Level Set method; Numerical assessment
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APA (6th Edition):
Ovsyannikov, A. (2013). Nouveau développement de la méthode Level Set sur la base d'une équation modifiée de suivi d'interface : Further development of Level Set method : modified level set equation and its numerical assessment. (Doctoral Dissertation). Ecully, Ecole centrale de Lyon. Retrieved from http://www.theses.fr/2013ECDL0013
Chicago Manual of Style (16th Edition):
Ovsyannikov, Andrey. “Nouveau développement de la méthode Level Set sur la base d'une équation modifiée de suivi d'interface : Further development of Level Set method : modified level set equation and its numerical assessment.” 2013. Doctoral Dissertation, Ecully, Ecole centrale de Lyon. Accessed March 05, 2021.
http://www.theses.fr/2013ECDL0013.
MLA Handbook (7th Edition):
Ovsyannikov, Andrey. “Nouveau développement de la méthode Level Set sur la base d'une équation modifiée de suivi d'interface : Further development of Level Set method : modified level set equation and its numerical assessment.” 2013. Web. 05 Mar 2021.
Vancouver:
Ovsyannikov A. Nouveau développement de la méthode Level Set sur la base d'une équation modifiée de suivi d'interface : Further development of Level Set method : modified level set equation and its numerical assessment. [Internet] [Doctoral dissertation]. Ecully, Ecole centrale de Lyon; 2013. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2013ECDL0013.
Council of Science Editors:
Ovsyannikov A. Nouveau développement de la méthode Level Set sur la base d'une équation modifiée de suivi d'interface : Further development of Level Set method : modified level set equation and its numerical assessment. [Doctoral Dissertation]. Ecully, Ecole centrale de Lyon; 2013. Available from: http://www.theses.fr/2013ECDL0013
University of Houston
2.
Zhang, Lan 1985-.
NUMERICAL SIMULATION OF TWO-PHASE FLOW USING THE LEVEL SET APPROACH.
Degree: PhD, Mathematics, 2014, University of Houston
URL: http://hdl.handle.net/10657/1683
► In this dissertation, we present numerical schemes in simulating immiscible two-phase flow problems. The goal of this work is to find unified solutions for numerical…
(more)
▼ In this dissertation, we present numerical schemes in simulating immiscible two-phase flow problems. The goal of this work is to find unified solutions for numerical modeling of any kind of immiscible two-phase flow with moving interface. Fluid flows are modeled using Navier Stokes equations with discontinuous coefficients. We introduce the Volume Fraction
method to evaluate discontinuous integrals arise from the variational formulation in the Finite Element
method. The use of Volume Fraction
method avoids the approximation of the Dirac Delta function, and therefore no regularization procedures are needed. Several operator splitting variants are studied in detail in linearized and non-linearized fashion, when we want to evaluate the discontinuous coefficients. Interface is captured using the
Level Set approach, where a transport equation is solved numerically with fourth order scheme without any stabilization terms. The surface tension effect is implemented in a semi-implicit way, thus larger time steps can be used compared with the explicit
method. A recent, well-developed re-initialization technique is included as a way to preserve the signed distance property of the
Level Set function. All mentioned numerical methods are used to build two-dimensional solvers. Solvers have been tested both with single-phase flow and two-phase flow benchmark problems. In particular, the bubble dynamics are presented to validate stated numerical schemes.
Advisors/Committee Members: Canic, Suncica (advisor), Kuzmin, Dmitri (committee member), Gorb, Yuliya (committee member), Perepelitsa, Mikhail (committee member).
Subjects/Keywords: Two-phase flow; Level Set method
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APA (6th Edition):
Zhang, L. 1. (2014). NUMERICAL SIMULATION OF TWO-PHASE FLOW USING THE LEVEL SET APPROACH. (Doctoral Dissertation). University of Houston. Retrieved from http://hdl.handle.net/10657/1683
Chicago Manual of Style (16th Edition):
Zhang, Lan 1985-. “NUMERICAL SIMULATION OF TWO-PHASE FLOW USING THE LEVEL SET APPROACH.” 2014. Doctoral Dissertation, University of Houston. Accessed March 05, 2021.
http://hdl.handle.net/10657/1683.
MLA Handbook (7th Edition):
Zhang, Lan 1985-. “NUMERICAL SIMULATION OF TWO-PHASE FLOW USING THE LEVEL SET APPROACH.” 2014. Web. 05 Mar 2021.
Vancouver:
Zhang L1. NUMERICAL SIMULATION OF TWO-PHASE FLOW USING THE LEVEL SET APPROACH. [Internet] [Doctoral dissertation]. University of Houston; 2014. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/10657/1683.
Council of Science Editors:
Zhang L1. NUMERICAL SIMULATION OF TWO-PHASE FLOW USING THE LEVEL SET APPROACH. [Doctoral Dissertation]. University of Houston; 2014. Available from: http://hdl.handle.net/10657/1683
Penn State University
3.
Raic, Zeljko.
Cerebrospinal Fluid and Brain Tissue Segmentation in Hydrocephalic Patients via Three Dimensional Level Set Method.
Degree: 2013, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/19984
► Volume segmentation of medical image data shows great promise in assisting physicians with diagnosis and treatment. This thesis applies an automated level set method in…
(more)
▼ Volume segmentation of medical image data shows great promise in assisting physicians with diagnosis and treatment. This thesis applies an automated
level set method in 3D for segmenting cerebrospinal fluid and brain tissue regions from CT scans of hydrocephalic patients. The
level set algorithm used in this work is based on central voxel intensity of source data and mean curvature of the interface. Parameters of the
level set equation are determined based on target region properties from CT scans and the algorithm is initialized using a signed distance transform with the standard Euclidean metric. We use the forward Euler
method with upwind differencing to propagate the solution forward in time which combined with an imposed stability condition guarantees convergence. The segmentation results show less than 1% error in cerebrospinal fluid volume and 1.5% in brain tissue volume in comparison to those obtained via stereo investigator. Robustness of the
level set method is evaluated by a sensitivity analysis of two initialization parameters which shows a linear relationship between the perturbation and error.
Advisors/Committee Members: Jack Langelaan, Thesis Advisor/Co-Advisor.
Subjects/Keywords: 3D level set; hydrocephalus; volume segmentation; medical image segmentation; level set method
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APA (6th Edition):
Raic, Z. (2013). Cerebrospinal Fluid and Brain Tissue Segmentation in Hydrocephalic Patients via Three Dimensional Level Set Method. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/19984
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Raic, Zeljko. “Cerebrospinal Fluid and Brain Tissue Segmentation in Hydrocephalic Patients via Three Dimensional Level Set Method.” 2013. Thesis, Penn State University. Accessed March 05, 2021.
https://submit-etda.libraries.psu.edu/catalog/19984.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Raic, Zeljko. “Cerebrospinal Fluid and Brain Tissue Segmentation in Hydrocephalic Patients via Three Dimensional Level Set Method.” 2013. Web. 05 Mar 2021.
Vancouver:
Raic Z. Cerebrospinal Fluid and Brain Tissue Segmentation in Hydrocephalic Patients via Three Dimensional Level Set Method. [Internet] [Thesis]. Penn State University; 2013. [cited 2021 Mar 05].
Available from: https://submit-etda.libraries.psu.edu/catalog/19984.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Raic Z. Cerebrospinal Fluid and Brain Tissue Segmentation in Hydrocephalic Patients via Three Dimensional Level Set Method. [Thesis]. Penn State University; 2013. Available from: https://submit-etda.libraries.psu.edu/catalog/19984
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
4.
Karpouzas, Georgios.
A hybrid method for shape and topology optimization in fluid mechanics.
Degree: 2019, National Technical University of Athens (NTUA); Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ)
URL: http://hdl.handle.net/10442/hedi/46428
► Adjoint optimisation is an exciting and fast growing research and application field in Computational Fluid Dynamics (CFD). It is widely used in shape, topology, flow…
(more)
▼ Adjoint optimisation is an exciting and fast growing research and application field in Computational Fluid Dynamics (CFD). It is widely used in shape, topology, flow control, error estimation, inverse, and robust design optimisation problems. The present thesis focuses on the first two categories: shape and topology optimisation. The two methods in question historically have very distinct characteristics and, as a result of these differences, the usage of one or the other method may have clear advantages and/or disadvantages in the context of individual optimization problems. The method chosen for a specific optimisation problem can, thus, have distinct advantages over the other in terms of how much improvement in design can be practically achieved. Our ultimate aim is to overcome, to a significant extent, these limitations by hybridising the two methods.To achieve this end, it is necessary to understand both the strengths and weaknesses of the available methodologies and how they arise in the context of the optimisation system. First, the accuracy issue regarding the modelling of the solid regions in porositybased topology optimisation is examined and it is found that many of the problems relate to the lack of an exact interface between the solid and fluid regions. Extending the topology optimisation framework to incorporate a welldefined interface, using the levelset method, alleviates some of these problems. However, the correct implementation of nearwall turbulence modelling remains an issue. Using the volumeaveraged total pressure losses as an objective function, levelset based topology optimisation is used to optimize the design of: i) a rightangled duct; ii) a heating, ventilation, and airconditioning (HVAC) duct; iii) the inlet and outlet ducts of a gearpump; and iv) a cold air intake system (CAIS) of a car.In the second part of this thesis, a novel method called Generalised Internal Boundary (GIB) is derived, implemented and validated, which allows for the imposition of exact boundary conditions internal to the computational domain. This is achieved without changing the topology/connectivity of the computational mesh, which dramatically improves the algorithms’ performance.To realise their full potential, the new boundaries must be able to physically deform and move. However, transitioning elements over the interface from solid to fluid (and vice versa) introduces discontinuities in the timehistory of the solution fields. These timehistories are critical to the solution of governing equations incorporating timederivatives. Thus, it is necessary to reconstruct the old time values of the fields so they appear smooth, yet conservative, from the perspective of the conservation equations. In this context, an ArbitraryLagrangianEulerian (ALE) framework that incorporates the conservative reconstruction of old timefield values in the presence of strongly discontinuous cell transition events is proposed. The results of the proposed method were compared against the bodyfitted approach of the flow around a moving…
Subjects/Keywords: Συνεχής συζυγής μέθοδος; Μέθοδος level-Set; Γενικευμένα εσωτερικά όρια (GIB ); Continuous conjugation method; Level-Set method; GIB method
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APA (6th Edition):
Karpouzas, G. (2019). A hybrid method for shape and topology optimization in fluid mechanics. (Thesis). National Technical University of Athens (NTUA); Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ). Retrieved from http://hdl.handle.net/10442/hedi/46428
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Karpouzas, Georgios. “A hybrid method for shape and topology optimization in fluid mechanics.” 2019. Thesis, National Technical University of Athens (NTUA); Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ). Accessed March 05, 2021.
http://hdl.handle.net/10442/hedi/46428.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Karpouzas, Georgios. “A hybrid method for shape and topology optimization in fluid mechanics.” 2019. Web. 05 Mar 2021.
Vancouver:
Karpouzas G. A hybrid method for shape and topology optimization in fluid mechanics. [Internet] [Thesis]. National Technical University of Athens (NTUA); Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ); 2019. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/10442/hedi/46428.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Karpouzas G. A hybrid method for shape and topology optimization in fluid mechanics. [Thesis]. National Technical University of Athens (NTUA); Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ); 2019. Available from: http://hdl.handle.net/10442/hedi/46428
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
5.
Swierstra, Marco (author).
Post-Processing of Topology Optimized Results: A method for retrieving smooth and crisp geometries.
Degree: 2017, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:0db4da1e-07e5-433f-a261-3dc0cd6abfc0
► Structural design optimization is the process of obtaining an optimized structure while satisfying a set of criteria. The process can be divided into three stages:…
(more)
▼ Structural design optimization is the process of obtaining an optimized structure while satisfying a
set of criteria. The process can be divided into three stages: topology optimization (stage one), geometry extraction (stage two) and shape optimization (stage three). The last two stages are regarded to be the post-processor of topology optimized results and this MSc. Thesis proposes a new
method for this part. At stage one, topology optimized results show unwanted features, namely jagged boundaries (i.e. poor smoothness) and intermediate densities (i.e. poor crispness). The post-processor should overcome these unwanted properties. During post-processing the geometry is described implicitly by a
Level Set Function (LSF). The zero-
level contour of the LSF describes the actual geometry. The LSF is constructed by summing a
set of Radial Basis Functions (RBFs) each multiplied with a weight, resulting in a smooth summation. At stage two, a geometry is extracted by setting up and solving a
set of equations linking the RBFs to the densities obtained at stage one. At stage three, a shape optimization is done to compensate the loss of structural performance, which resulted from translating the densities to an LSF at stage two. The geometry described by the LSF does not match the mesh created for stage one. A fictitious domain
method called the Finite Cell
Method (FCM) is used to perform a structural analysis on the non-matching mesh. A sensitivity analysis is done to provide gradient information to the gradient-based optimizer, the
Method of Moving Asymptotes (MMA). Controlling the slope of the LSF is needed to make sure the sensitivities do not become zero throughout the domain. The maximum possible slope of the LSF can be fixed by setting a bound on the weights of the RBFs. Furthermore, intermediate densities are penalized such that these provide relatively low stiffness compared to its material use. Several case studies are done using the proposed
method. The post-processor: (1) improves the smoothness due to the use of the smooth LSF, (2) decreases the amount of intermediate densities by an average factor of 5.5 and (3) achieves an average 10% improve in performance between stage two and three. The computation time is strongly problem dependent, test cases are either: slower, equally fast or faster than the topology optimization of stage one.
Advisors/Committee Members: Langelaar, Matthijs (mentor), Gupta, Deepak (mentor), Hendriks, M.A.N. (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: topology optimization; shape optimization; Level Set Method; Finite Cell Method
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APA (6th Edition):
Swierstra, M. (. (2017). Post-Processing of Topology Optimized Results: A method for retrieving smooth and crisp geometries. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:0db4da1e-07e5-433f-a261-3dc0cd6abfc0
Chicago Manual of Style (16th Edition):
Swierstra, Marco (author). “Post-Processing of Topology Optimized Results: A method for retrieving smooth and crisp geometries.” 2017. Masters Thesis, Delft University of Technology. Accessed March 05, 2021.
http://resolver.tudelft.nl/uuid:0db4da1e-07e5-433f-a261-3dc0cd6abfc0.
MLA Handbook (7th Edition):
Swierstra, Marco (author). “Post-Processing of Topology Optimized Results: A method for retrieving smooth and crisp geometries.” 2017. Web. 05 Mar 2021.
Vancouver:
Swierstra M(. Post-Processing of Topology Optimized Results: A method for retrieving smooth and crisp geometries. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Mar 05].
Available from: http://resolver.tudelft.nl/uuid:0db4da1e-07e5-433f-a261-3dc0cd6abfc0.
Council of Science Editors:
Swierstra M(. Post-Processing of Topology Optimized Results: A method for retrieving smooth and crisp geometries. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:0db4da1e-07e5-433f-a261-3dc0cd6abfc0
Delft University of Technology
6.
Kerst, A. (author).
A volume-conserving interface-correction level-set method on unstructured triangular meshes.
Degree: 2020, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:f75dbc0f-e7db-4ba3-a168-eb74da7ac390
► The level-set (LS) method uses a signed-distance function to capture the interface in two-phase flows. Geometrical properties can be easily obtained, and merging and splitting…
(more)
▼ The
level-
set (LS)
method uses a signed-distance function to capture the interface in two-phase flows. Geometrical properties can be easily obtained, and merging and splitting of the interface are handled automatically by the LS
method. However, it is not inherently volume conserving. Several methods found in literature that aim to solve this problem are discussed in this report, including the interface-correction
level-
set (ICLS)
method. The ICLS
method uses an additional advection step with a correction-velocity field to restore global volume loss/gain. We present the volume-of-fluid-based local interface-correction
level-
set (VOF-LICLS)
method. This is an extension to the ICLS
method that aims to restore volume locally. This is achieved by coupling the ICLS
method with the VoF
method. In each time step we evolve both the
level-
set function and the volume fraction function. The VoF advection is performed using a Lagrangian-Eulerian
method on a dual mesh. From the advected LS field volume fractions are constructed and compared to the advected VoF field. This allows us to use local volume fluxes for the velocity field, instead of a global volume flux. The construction of the correction-velocity is performed with the use of an analytic equation and the local volume fluxes. The novel volume correction procedure is then executed iteratively. The
level-
set equation is discretized in space with a finite element approach. Instabilities occur for the standard Galerkin approach for pure advection equation, so the SUPG
method is used in order to obtain stable solutions. The performance of the developed
method in this thesis is compared with LS and ICLS for three different test cases. We report a significant improvement for local volume conservation, and we observe that VOF-LICLS yields more accurate interface positions.
Advisors/Committee Members: den Ouden-van der Horst, D. (mentor), Vuik, C. (graduation committee), Möller, M. (graduation committee), Meulenbroek, B.J. (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: Level-set method; Volume-conserving; Finite element method
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APA ·
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APA (6th Edition):
Kerst, A. (. (2020). A volume-conserving interface-correction level-set method on unstructured triangular meshes. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:f75dbc0f-e7db-4ba3-a168-eb74da7ac390
Chicago Manual of Style (16th Edition):
Kerst, A (author). “A volume-conserving interface-correction level-set method on unstructured triangular meshes.” 2020. Masters Thesis, Delft University of Technology. Accessed March 05, 2021.
http://resolver.tudelft.nl/uuid:f75dbc0f-e7db-4ba3-a168-eb74da7ac390.
MLA Handbook (7th Edition):
Kerst, A (author). “A volume-conserving interface-correction level-set method on unstructured triangular meshes.” 2020. Web. 05 Mar 2021.
Vancouver:
Kerst A(. A volume-conserving interface-correction level-set method on unstructured triangular meshes. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Mar 05].
Available from: http://resolver.tudelft.nl/uuid:f75dbc0f-e7db-4ba3-a168-eb74da7ac390.
Council of Science Editors:
Kerst A(. A volume-conserving interface-correction level-set method on unstructured triangular meshes. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:f75dbc0f-e7db-4ba3-a168-eb74da7ac390
7.
Vitorio Junior, Paulo Cezar.
Análise Level Set da otimização topológica de estruturas planas utilizando o Método dos Elementos de Contorno.
Degree: Mestrado, Estruturas, 2014, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/18/18134/tde-24092014-150115/
;
► A otimização topológica de estruturas está relacionada à concepção de projetos que executem suas funções com nível de segurança adequado empregando a quantidade mínima de…
(more)
▼ A otimização topológica de estruturas está relacionada à concepção de projetos que executem suas funções com nível de segurança adequado empregando a quantidade mínima de material. Neste trabalho, determina-se a geometria ótima de estruturas planas por meio do acoplamento do Método dos Elementos de Contorno (MEC) ao Método Level Set (MLS). O algoritmo é composto por 3 etapas: problema mecânico, otimização topológica e reconstrução da estrutura. O problema mecânico é resolvido pelas equações algébricas do MEC. A otimização topológica é determinada pelo MLS, este representa a geometria do corpo e suas evoluções por meio da função Level Set (LS) avaliada em seu nível zero. Na reconstrução realiza-se o remalhamento, pois a cada iteração a estrutura é modificada. O acoplamento proposto resulta na geometria ótima da estrutura sem a necessidade da aplicação de filtros. Os exemplos analisados mostram que algoritmo desenvolvido capta adequadamente a geometria ótima das estruturas. Com esse trabalho, avança-se no campo das aplicações do acoplamento MEC-MLS e no desenvolvimento de soluções inovadoras para problemas complexos de engenharia.
In general, the topological optimization of structures is related to design projects that perform their functions with appropriate security levels using the minimum amount of material. This research determines the optimal geometry of 2D structures by coupling the Boundary Blement Method (BEM) to Level Set Method (LSM). The algorithm consists of 3 steps: mechanical model, topology optimization and structure reconstruction. The mechanical model is solved by BEM algebraic equations. The topology optimization is determined using the MLS, the geometry of the body is determined by the Level Set (LS) function evaluated at the zero level. The reconstruction achieves the remeshing, because for each iteration of the structure is modified. The proposed coupling results in the optimal geometry of the structure without the filters application. The examples show that the algorithm developed captures adequately the optimal geometry of the structures. With this dissertation, it is possible advance in the field of applications of the BEM - LSM and develop innovative solutions to complex engineering problems.
Advisors/Committee Members: Leonel, Edson Denner.
Subjects/Keywords: Boundary Element Method; Level Set method; Método dos Elementos de Contorno; Método Level Set; Otimização topológica; Topology optimization
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APA (6th Edition):
Vitorio Junior, P. C. (2014). Análise Level Set da otimização topológica de estruturas planas utilizando o Método dos Elementos de Contorno. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/18/18134/tde-24092014-150115/ ;
Chicago Manual of Style (16th Edition):
Vitorio Junior, Paulo Cezar. “Análise Level Set da otimização topológica de estruturas planas utilizando o Método dos Elementos de Contorno.” 2014. Masters Thesis, University of São Paulo. Accessed March 05, 2021.
http://www.teses.usp.br/teses/disponiveis/18/18134/tde-24092014-150115/ ;.
MLA Handbook (7th Edition):
Vitorio Junior, Paulo Cezar. “Análise Level Set da otimização topológica de estruturas planas utilizando o Método dos Elementos de Contorno.” 2014. Web. 05 Mar 2021.
Vancouver:
Vitorio Junior PC. Análise Level Set da otimização topológica de estruturas planas utilizando o Método dos Elementos de Contorno. [Internet] [Masters thesis]. University of São Paulo; 2014. [cited 2021 Mar 05].
Available from: http://www.teses.usp.br/teses/disponiveis/18/18134/tde-24092014-150115/ ;.
Council of Science Editors:
Vitorio Junior PC. Análise Level Set da otimização topológica de estruturas planas utilizando o Método dos Elementos de Contorno. [Masters Thesis]. University of São Paulo; 2014. Available from: http://www.teses.usp.br/teses/disponiveis/18/18134/tde-24092014-150115/ ;
8.
Jung, Yeonhee.
An efficient analysis of resin transfer molding process using extended finite element method : Une analyse efficace du procédé RTM à l’aide de la méthode XFEM.
Degree: Docteur es, Mécanique et Ingénierie, 2013, Saint-Etienne, EMSE; Seoul National University
URL: http://www.theses.fr/2013EMSE0701
► Le procédé de fabrication par RTM (Resin Transfer Molding) a été étudié numériquement à l’aide de la méthode XFEM (eXtended Finite Element Method) combinée avec…
(more)
▼ Le procédé de fabrication par RTM (Resin Transfer Molding) a été étudié numériquement à l’aide de la méthode XFEM (eXtended Finite Element Method) combinée avec la méthode Level set. La méthode XFEM permet d’obtenir une bonne précision numérique de la pression près du front d’écoulement, où son gradient est discontinu. Les fonctions de forme enrichies de la méthode XFEM sont proposées à l’aide des valeurs de Level set en vue de décrire correctement l’interpolation avec le front d’écoulement. En plus, la méthode de Level set est utilisée pour transporter le front d’écoulement à chaque pas de temps durant le remplissage du moule. Les valeurs de Level set sont calculées à l’aide d’une méthode de Galerkin implicite. Le solveur multi-frontal d’IPSAP a été utilisé pour la résolution du système. Cette étude a été validée en comparaison avec les solutions analytiques.En outre, une méthode de localisation avec XFEM et la méthode Level set a été proposée afin d’améliorer l’efficacité de calcul. Elle permet de réduire le domaine de calcul près du front d’écoulement. Par conséquent, le temps de calcul est fortement réduit grâce à cette méthode. Un test d’efficacité a été fait avec des modèles simples en écoulement laminaire ou radial.Quelques exemples d’application sont présentés pour illustrer la capacité de cette méthode. Une pale d’éolienne a également traitée comme application industrielle. Enfin, une interface d’utilisateur graphique a été développée en vue de fournir une facilité des pré- et post-processus.
Numerical simulation for Resin Transfer Molding (RTM) manufacturing process is attempted by using the eXtended Finite Element Method (XFEM) combined with the level set method. XFEM allows to obtaining a good numerical precision of the pressure near the resin flow front, where its gradient is discontinuous. The enriched shape functions of XFEM are derived by using the level set values so as to correctly describe the interpolation with the resin flow front. In addition, the level set method is used to transport the resin flow front at each time step during the mold filling. The level set values are calculated by an implicit characteristic Galerkin FEM. The multi-frontal solver of IPSAP is adopted to solve the system. This work is validated by comparing the obtained results with analytic solutions.Moreover, a localization method of XFEM and level set method is proposed to increase the computing efficiency. The computation domain is reduced to the small region near the resin flow front. Therefore, the total computing time is strongly reduced by it. The efficiency test is made with simple channel or radial flow models. Several application examples are analyzed to demonstrate ability of this method. A wind turbine blade is also treated as industrial application. Finally, a Graphic User Interface (GUI) tool is developed so as to make easy the pre/post-processing of the simulation.
Advisors/Committee Members: Han, Woo-Suck (thesis director), Kim, Seung Jo (thesis director).
Subjects/Keywords: Procédé RTM; XFEM; Level set; Simulation numérique; Méthode de localisation; RTM Process; XFEM; Level Set Method; Localization Method; Numerical Analysis
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APA (6th Edition):
Jung, Y. (2013). An efficient analysis of resin transfer molding process using extended finite element method : Une analyse efficace du procédé RTM à l’aide de la méthode XFEM. (Doctoral Dissertation). Saint-Etienne, EMSE; Seoul National University. Retrieved from http://www.theses.fr/2013EMSE0701
Chicago Manual of Style (16th Edition):
Jung, Yeonhee. “An efficient analysis of resin transfer molding process using extended finite element method : Une analyse efficace du procédé RTM à l’aide de la méthode XFEM.” 2013. Doctoral Dissertation, Saint-Etienne, EMSE; Seoul National University. Accessed March 05, 2021.
http://www.theses.fr/2013EMSE0701.
MLA Handbook (7th Edition):
Jung, Yeonhee. “An efficient analysis of resin transfer molding process using extended finite element method : Une analyse efficace du procédé RTM à l’aide de la méthode XFEM.” 2013. Web. 05 Mar 2021.
Vancouver:
Jung Y. An efficient analysis of resin transfer molding process using extended finite element method : Une analyse efficace du procédé RTM à l’aide de la méthode XFEM. [Internet] [Doctoral dissertation]. Saint-Etienne, EMSE; Seoul National University; 2013. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2013EMSE0701.
Council of Science Editors:
Jung Y. An efficient analysis of resin transfer molding process using extended finite element method : Une analyse efficace du procédé RTM à l’aide de la méthode XFEM. [Doctoral Dissertation]. Saint-Etienne, EMSE; Seoul National University; 2013. Available from: http://www.theses.fr/2013EMSE0701
Penn State University
9.
Baran, Matthew Stephen.
A Computational Study of Robustness in Level Set Surface Reconstruction.
Degree: 2012, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/13717
► This thesis examines the performance of the local level set method on the surface reconstruction problem for unorganized point clouds in three dimensions. Many laser-ranging,…
(more)
▼ This thesis examines the performance of the local
level set method on the surface reconstruction problem for unorganized point clouds in three dimensions. Many laser-ranging, stereo, and structured light devices produce three dimensional information in the form of unorganized point clouds. The point clouds are sampled from surfaces embedded in three-space from the viewpoint of a camera focal plane or laser receiver. The reconstruction of these objects in the form of a triangulated geometric surface is an important step in computer vision and image processing. The local
level set method uses a Hamilton-Jacobi partial differential equation to describe the motion of an implicit surface in three dimensions. An initial surface which encloses the data is allowed to move until it becomes a smooth fit of the unorganized data. A 3D point cloud test suite was assembled from publicly available laser-scanned databases. The test suite exhibits nonuniform sampling rates and various noise characteristics to challenge the surface reconstruction algorithm. Quantitative metrics are introduced to capture the accuracy and efficiency of surface reconstruction on the degraded data. The results characterize the robustness of the
level set method for surface reconstruction as applied to 3D remote sensing.
Advisors/Committee Members: Qiang Du, Thesis Advisor/Co-Advisor.
Subjects/Keywords: Surface reconstruction; Level set method; Point Cloud; Robustness
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APA (6th Edition):
Baran, M. S. (2012). A Computational Study of Robustness in Level Set Surface Reconstruction. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/13717
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Baran, Matthew Stephen. “A Computational Study of Robustness in Level Set Surface Reconstruction.” 2012. Thesis, Penn State University. Accessed March 05, 2021.
https://submit-etda.libraries.psu.edu/catalog/13717.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Baran, Matthew Stephen. “A Computational Study of Robustness in Level Set Surface Reconstruction.” 2012. Web. 05 Mar 2021.
Vancouver:
Baran MS. A Computational Study of Robustness in Level Set Surface Reconstruction. [Internet] [Thesis]. Penn State University; 2012. [cited 2021 Mar 05].
Available from: https://submit-etda.libraries.psu.edu/catalog/13717.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Baran MS. A Computational Study of Robustness in Level Set Surface Reconstruction. [Thesis]. Penn State University; 2012. Available from: https://submit-etda.libraries.psu.edu/catalog/13717
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Brigham Young University
10.
Bryson, Joshua A.
Soap Bubbles and Solid Spheres: Collisions and Interactions.
Degree: MS, 2011, Brigham Young University
URL: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=4015&context=etd
► Under the right conditions, a moving sphere may successfully enter, and leave, a soap bubble without rupturing that bubble. The physics behind this phenomena are…
(more)
▼ Under the right conditions, a moving sphere may successfully enter, and leave, a soap bubble without rupturing that bubble. The physics behind this phenomena are not well understood, nor the limiting factors (such as sphere size, speed, etc.). This work, investigating this phenomenon using high speed photography, has produced several results which are presented. First, several distinct regimes, noted while photographing the interactions between the spheres and the bubbles, are classified and discussed. Next a probabilistic examination of the soap bubbles rupture by the moving spheres is presented. Then a conjecture for the limiting sphere sizes and speeds is presented. And finally some interesting phenomena, noted in the course of this investigation, are presented and discussed.
Subjects/Keywords: soap bubbles; lapace equation; level set method; weber number; Mechanical Engineering
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APA (6th Edition):
Bryson, J. A. (2011). Soap Bubbles and Solid Spheres: Collisions and Interactions. (Masters Thesis). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=4015&context=etd
Chicago Manual of Style (16th Edition):
Bryson, Joshua A. “Soap Bubbles and Solid Spheres: Collisions and Interactions.” 2011. Masters Thesis, Brigham Young University. Accessed March 05, 2021.
https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=4015&context=etd.
MLA Handbook (7th Edition):
Bryson, Joshua A. “Soap Bubbles and Solid Spheres: Collisions and Interactions.” 2011. Web. 05 Mar 2021.
Vancouver:
Bryson JA. Soap Bubbles and Solid Spheres: Collisions and Interactions. [Internet] [Masters thesis]. Brigham Young University; 2011. [cited 2021 Mar 05].
Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=4015&context=etd.
Council of Science Editors:
Bryson JA. Soap Bubbles and Solid Spheres: Collisions and Interactions. [Masters Thesis]. Brigham Young University; 2011. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=4015&context=etd
Brigham Young University
11.
Patty, Spencer R.
3D Image Reconstruction and Level Set Methods.
Degree: MS, 2011, Brigham Young University
URL: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3811&context=etd
► We give a concise explication of the theory of level set methods for modeling motion of an interface as well as the numerical implementation of…
(more)
▼ We give a concise explication of the theory of level set methods for modeling motion of an interface as well as the numerical implementation of these methods. We then introduce the geometry of a camera and the mathematical models for 3D reconstruction with a few examples both simulated and from a real camera. We finally describe the model for 3D surface reconstruction from n-camera views using level set methods.
Subjects/Keywords: Level Set Method; PDE; Differential Geometry; Computer Vision; 3D Reconstruction; Mathematics
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APA (6th Edition):
Patty, S. R. (2011). 3D Image Reconstruction and Level Set Methods. (Masters Thesis). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3811&context=etd
Chicago Manual of Style (16th Edition):
Patty, Spencer R. “3D Image Reconstruction and Level Set Methods.” 2011. Masters Thesis, Brigham Young University. Accessed March 05, 2021.
https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3811&context=etd.
MLA Handbook (7th Edition):
Patty, Spencer R. “3D Image Reconstruction and Level Set Methods.” 2011. Web. 05 Mar 2021.
Vancouver:
Patty SR. 3D Image Reconstruction and Level Set Methods. [Internet] [Masters thesis]. Brigham Young University; 2011. [cited 2021 Mar 05].
Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3811&context=etd.
Council of Science Editors:
Patty SR. 3D Image Reconstruction and Level Set Methods. [Masters Thesis]. Brigham Young University; 2011. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3811&context=etd
Delft University of Technology
12.
Mozo Gutierrez, Alvaro (author).
FSI Analysis and Optimization of 3D beam structures.
Degree: 2018, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:ba778a47-14c1-45d0-870a-24b698096e3a
► Aiming to enhance the performance of the industrial design process, structural optimization techniques have been proposed as an alternative to traditional design and optimization techniques.…
(more)
▼ Aiming to enhance the performance of the industrial design process, structural optimization techniques have been proposed as an alternative to traditional design and optimization techniques. They own the potential of achieving an optimal distribution of the material through the design domain, thus reducing waste loss and weight, and increasing the ability to carry the loads and the overall efficiency of the design. During this thesis work it has been developed a 3D Fluid-Structure Interaction model for beam-like structures, such as wind turbine blades. The cross-section geometry of the beam can be optimized using structural optimization techniques, such as size, shape or topology optimization. The proposed 3D beam is partially based on the formulation of the classical beam element for slender beams (Euler-Bernoulli), including Saint-Venant torsional effects for isotropic materials, and with the addition of the terms related with the coupling between axial and torsion, and bending and torsion contributions, which may arise when using non-linear materials. The stiffness information of the beam is interpolated from its cross-section geometries and materials, which can vary along the beam length. The cross-section geometries are defined on a XFEM mesh. The fluid and solid domains are specified using a Level Set Function. This provides a smooth geometry and crisp representation of the solid/fluid interface without the necessity of re-meshing, as in the case of classical FEM. A 2D fluid simulation based on Incompressible Navier Stokes flow at low Reynolds number is carried around each cross-section, in order to obtain the aerodynamic loading over its contour. This aerodynamic loading serves as an input for the beam model, to compute deformation of the beam. This deformation is mapped onto the cross-sections, obtaining the updated displacements and rotations of the geometry. With the updated geometry the fluid field is altered and it needs to be updated as well, forming a non-linear iterative process that loops until a converged structure is obtained. The 3D FSI model is solved on a monolithic Newton-Raphson solver that treats all the equations involved at once. The Jacobian terms derived for the monolithic solving scheme that has been developed for the forward analysis allow a straightforward computation of the sensitivities using adjoint method. This sensitivity analysis makes possible the optimization of the geometry of the cross-sections based on certain criteria and constraints.
Aerospace Structures and Materials Engineering
Advisors/Committee Members: Turteltaub, Sergio (mentor), Maute, K (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: 3D Beam; FSI; XFEM; Level Set Method; Sensitivity Analysis; Optimization
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APA (6th Edition):
Mozo Gutierrez, A. (. (2018). FSI Analysis and Optimization of 3D beam structures. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:ba778a47-14c1-45d0-870a-24b698096e3a
Chicago Manual of Style (16th Edition):
Mozo Gutierrez, Alvaro (author). “FSI Analysis and Optimization of 3D beam structures.” 2018. Masters Thesis, Delft University of Technology. Accessed March 05, 2021.
http://resolver.tudelft.nl/uuid:ba778a47-14c1-45d0-870a-24b698096e3a.
MLA Handbook (7th Edition):
Mozo Gutierrez, Alvaro (author). “FSI Analysis and Optimization of 3D beam structures.” 2018. Web. 05 Mar 2021.
Vancouver:
Mozo Gutierrez A(. FSI Analysis and Optimization of 3D beam structures. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Mar 05].
Available from: http://resolver.tudelft.nl/uuid:ba778a47-14c1-45d0-870a-24b698096e3a.
Council of Science Editors:
Mozo Gutierrez A(. FSI Analysis and Optimization of 3D beam structures. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:ba778a47-14c1-45d0-870a-24b698096e3a
Delft University of Technology
13.
Verbeek, Thijs (author).
Modeling and simulating three phases of steel: Austenite, ferrite and cementite.
Degree: 2018, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:5850a4ad-2e7a-43f9-ae0e-4971c9bfd3d4
► In the work of Den Ouden the level-set method has been used to model the growth and dissolution in a steel alloy of the precipitate…
(more)
▼ In the work of Den Ouden the
level-
set method has been used to model the growth and dissolution in a steel alloy of the precipitate cementite and the diffusive phase austenite. The movement of the interface between the two phases is controlled by the diffusion of carbon and a reaction on the interface between the two phases. In this thesis research a similar model and
method is given for a three-phased model with an extra diffusive phase. This third phase is ferrite, which nucleates on the interface of austenite and cementite when the temperature is dropped below the eutectoid temperature for a high carbon steel alloy. The difference between austenite and ferrite is the matrix structure of the iron atoms. This influences how much carbon the phase can contain. The difference in structure also results in different properties of the steel with respect to strength, hardness, etc. Modeling the growth of this three-phased steel alloy could eventually lead to useful insights for high-carbon steel production.\ Extra difficulties arise by the introduction of a second diffusive phase. These difficulties concern defining sufficient interface boundary conditions between the different phases, capturing the different phases with the
level-
set method, creating a qualitative good mesh capturing these phases, recovering gradients on an interface and getting correct carbon concentration value in the triple points because of the interface boundary conditions. Except for the latter problem, the results of this research show decent results. The effect of cooling on the growth of ferrite is also shown and explained.
Advisors/Committee Members: den Ouden-van der Horst, Dennis (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: Level Set Method; Multi-phase simulations; Triple point
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APA (6th Edition):
Verbeek, T. (. (2018). Modeling and simulating three phases of steel: Austenite, ferrite and cementite. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:5850a4ad-2e7a-43f9-ae0e-4971c9bfd3d4
Chicago Manual of Style (16th Edition):
Verbeek, Thijs (author). “Modeling and simulating three phases of steel: Austenite, ferrite and cementite.” 2018. Masters Thesis, Delft University of Technology. Accessed March 05, 2021.
http://resolver.tudelft.nl/uuid:5850a4ad-2e7a-43f9-ae0e-4971c9bfd3d4.
MLA Handbook (7th Edition):
Verbeek, Thijs (author). “Modeling and simulating three phases of steel: Austenite, ferrite and cementite.” 2018. Web. 05 Mar 2021.
Vancouver:
Verbeek T(. Modeling and simulating three phases of steel: Austenite, ferrite and cementite. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Mar 05].
Available from: http://resolver.tudelft.nl/uuid:5850a4ad-2e7a-43f9-ae0e-4971c9bfd3d4.
Council of Science Editors:
Verbeek T(. Modeling and simulating three phases of steel: Austenite, ferrite and cementite. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:5850a4ad-2e7a-43f9-ae0e-4971c9bfd3d4
University of Arizona
14.
Zhang, Tiankui.
A Level Set Approach to Shape Dynamics of Vesicles
.
Degree: 2020, University of Arizona
URL: http://hdl.handle.net/10150/645773
► Cell membranes are crucial to the life of cells and vesicles are important model systems for cell membranes. In this thesis, we aim to understand…
(more)
▼ Cell membranes are crucial to the life of cells and vesicles are important model systems for cell membranes. In this thesis, we aim to understand shape transformation of vesicles with theoretical tools from differential geometry and numerical techniques within the framework of the
level set method.
Shape dynamics of vesicles has been investigated for many years since Helfrich proposed the famous quadratic curvature energy to explain shape of red blood cells in the 1970s. The Helfrich Hamiltonian ignores lateral inhomogeneity of the vesicle and higher order curvature energy terms. Therefore most researches taking the Helfrich model for granted ignores tangential dynamics and elastic forces for higher order terms. Recently, a more general Hamiltonian that includes all curvature scalars up to fourth order was proposed by Deserno. Our first job is to calculate all of the variations for this much more general Hamiltonian, which will prove useful for vesicle models beyond the Helfrich model. Inspired by the general Hamiltonian from Deserno, a general line energy is proposed in the thesis by the argument of symmetry. We then proceed to calculate all of the variations for the curvature scalar of curves. This yield very useful results for vesicles models with phase coexistence, open edges etc.
Numerical simulations also dates back to Helfrich's first paper. There are two approaches to the numerical simulation of vesicles in three dimensional space. In the first approach, a connected mesh is used to represent the surface. There two major difficulties with this methodology. The first arises when topological changes such as pinching off and fusion happen, which is fairly common for real biomembranes. The mesh needs to be separated or sewn together which can be quite involved. The other difficulty lie in the computation of surface geometries such as curvature and surface Laplacian of curvatures. The accuracy of the computation of such kind depends heavily on the quality of the mesh which is hard to maintain during larger deformations The other approach represents the surface implicitly as the
level sets of a higher dimensional function defined on a Eulerian grid. Notable examples are the phase field
method and the
level set method. The phase field
method is a diffusive boundary
method where the boundary is represented by a narrow band of grids. One of the drawback is that there are no straightforward techinques for converting arbitrary surface integral of surface and curve curvature scalars into the phase field model. Complicated mathematical proofs are needed to establish the equivalent between the phase field model and the sharp interface models. The
level set method is a sharp interface
method and it is easy to represent geometries with the
level set method. We therefore choose the
level set method as the numerical framework for our simulation. One major problem of the
level set is the requirement for reinitialization which introduces errors every time the
level set function is restored. To maintain accuracy of the
level set…
Advisors/Committee Members: Wolgemuth, Charles (advisor), Wolgemuth, Charles (committeemember), Manne, Srinivas (committeemember), Stafford, Charles A. (committeemember), Milsom, John A. (committeemember), Zhang-Molina, Calvin (committeemember).
Subjects/Keywords: 3d vesicle simulation;
level set method;
multiphase vesicle;
protein membrane interaction
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APA (6th Edition):
Zhang, T. (2020). A Level Set Approach to Shape Dynamics of Vesicles
. (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/645773
Chicago Manual of Style (16th Edition):
Zhang, Tiankui. “A Level Set Approach to Shape Dynamics of Vesicles
.” 2020. Doctoral Dissertation, University of Arizona. Accessed March 05, 2021.
http://hdl.handle.net/10150/645773.
MLA Handbook (7th Edition):
Zhang, Tiankui. “A Level Set Approach to Shape Dynamics of Vesicles
.” 2020. Web. 05 Mar 2021.
Vancouver:
Zhang T. A Level Set Approach to Shape Dynamics of Vesicles
. [Internet] [Doctoral dissertation]. University of Arizona; 2020. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/10150/645773.
Council of Science Editors:
Zhang T. A Level Set Approach to Shape Dynamics of Vesicles
. [Doctoral Dissertation]. University of Arizona; 2020. Available from: http://hdl.handle.net/10150/645773
15.
Jeon, Chan-Hoo.
Modeling of debris flows and induced phenomena with non-Newtonian fluid models.
Degree: PhD, Civil Engineering, 2015, University of Texas – Austin
URL: http://hdl.handle.net/2152/32822
► Debris flows contain inhomogeneous distributions of solids within a liquid. By considering a mixture of solid and liquid forming debris flows as a non-Newtonian continuous…
(more)
▼ Debris flows contain inhomogeneous distributions of solids within a liquid. By considering a mixture of solid and liquid forming debris flows as a non-Newtonian continuous liquid, the viscosity term for rheological models is simply constructed in the Navier-Stokes equations. Time-independent models (e.g. Herschel-Bulkely) for viscosity have been widely used, but there is an open question as to whether time-dependent models might provide improved results. In this work, both time-dependent and time-independent non-Newtonian fluid models are taken into account in simulation. Since debris flow induced phenomena include two or more interfaces, the
level set method for multiple materials is applied as the interface tracking
method. The numerical model is applied to two-dimensional test cases to validate this approach and analyze the relative importance of the viscosity model. The simulation results for the two models show reasonable agreement with available experimental data in most cases, however, time-dependent model only shows good correlation with experimental measurements for special case. It indicates that debris flows and induced phenomena could be simulated by the approach of this research and the time-dependent model is more adequate for representing real debris flows than time-independent models.
Advisors/Committee Members: Hodges, Ben R. (advisor), McKinney, Daene C (committee member), Liljestrand, Howard M (committee member), Moser, Robert D (committee member), Sepehrnoori, Kamy (committee member).
Subjects/Keywords: Debris flow; Non-Newtonian fluid; Modeling; Level set method
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APA (6th Edition):
Jeon, C. (2015). Modeling of debris flows and induced phenomena with non-Newtonian fluid models. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/32822
Chicago Manual of Style (16th Edition):
Jeon, Chan-Hoo. “Modeling of debris flows and induced phenomena with non-Newtonian fluid models.” 2015. Doctoral Dissertation, University of Texas – Austin. Accessed March 05, 2021.
http://hdl.handle.net/2152/32822.
MLA Handbook (7th Edition):
Jeon, Chan-Hoo. “Modeling of debris flows and induced phenomena with non-Newtonian fluid models.” 2015. Web. 05 Mar 2021.
Vancouver:
Jeon C. Modeling of debris flows and induced phenomena with non-Newtonian fluid models. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2015. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/2152/32822.
Council of Science Editors:
Jeon C. Modeling of debris flows and induced phenomena with non-Newtonian fluid models. [Doctoral Dissertation]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/32822
16.
Jedouaa, Meriem.
Une méthode efficace de capture d'interface pour la simulation de suspensions d'objets rigides et de vésicules immergées dans un fluide : An efficient interface capturing method to simulate dense suspensions of rigid bodies and vesicles immersed in a fluid.
Degree: Docteur es, Mathématiques Appliquées, 2017, Grenoble Alpes
URL: http://www.theses.fr/2017GREAM042
► Dans ce travail, nous nous sommes intéressés à la simulation numérique de suspensions denses d'objets immergés dans un fluide. En s'inspirant d'une méthode de segmentation…
(more)
▼ Dans ce travail, nous nous sommes intéressés à la simulation numérique de suspensions denses d'objets immergés dans un fluide. En s'inspirant d'une méthode de segmentation d'image, nous avons développé une méthode efficace de capture d'interface permettant d'une part de localiser les structures immergées et d'autre part de gérer les contacts numériques entre les structures.Le domaine fluide/structure est représenté à l'aide de trois fonctions labels et deux fonctions distances qui permettent de localiser chaque structure et son plus proche voisin.Les interfaces sont capturées par une seule fonction level set, celle-ci est ensuite transportée par la vitesse du fluide ou par la vitesse de chaque structure. Un algorithme de multi-label fast marching permet de réinitialiser à chaque pas de temps les fonctions labels et distances dans un périmètre proche des interfaces.La gestion des contacts numériques est effectuée grâce à une force répulsive à courte portée prenant en compte l'interaction entre les objets les plus proches.Dans un premier temps, la méthode est appliquée à l'évolution de solides rigides immergés.Un modèle de pénalisation global couplé aux fonctions labels permet de calculer en une seule fois l'ensemble des vitesses des structures rigides. Les résultats obtenus montrent l'efficacité de la méthode à gérer un grand nombre de solides.Nous avons ensuite appliqué la méthode des suspensions de vésicules immergées. Ce type de simulation requiert le calcul des forces élastiques et de courbures exercées sur les membranes. Grâce au modèle proposé, seulement une force élastique et une force de courbure sont calculées pour l'ensemble des membranes à l'aide de la fonction level set et des fonctions labels.
In this work, we propose a method to efficiently capture an arbitrary number of fluid/solid or fluid/fluid interfaces, in a level-set framework. This technique, borrowed from image analysis, is introduced in the context of the interaction of several bodies immersed in a fluid. A configuration of the bodies in the fluid/structure domain is described by three label maps providing the first and second neighbours, and their associated distance functions. Only one level set function captures the union of all interfaces and is transported with the fluid velocity or with a global velocity field which takes into account the velocity of each structure. A multi-label fast marching method is then performed in a narrow-band around the interfaces allowing to update the label and distance functions. Within this framework, the numerical treatment of contacts between the structures is achieved by a short-range repulsive force depending on the distance between the closest bodies.The method is validated through the simulation of a dense suspension of rigid bodies immersed in an incompressible fluid. A global penalization model uses the label maps to follow the solid bodies altogether without a separate computation of each body velocity. Consequently, the method shows its efficiency when dealing with a large number of rigid bodies.…
Advisors/Committee Members: Maitre, Emmanuel (thesis director), Bruneau, Charles-Henri (thesis director).
Subjects/Keywords: Interaction fluide/structure; Méthode level set; Modèle de collision; Fluid/structure interaction; Level set method; Multiple bodies; Collision model
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APA (6th Edition):
Jedouaa, M. (2017). Une méthode efficace de capture d'interface pour la simulation de suspensions d'objets rigides et de vésicules immergées dans un fluide : An efficient interface capturing method to simulate dense suspensions of rigid bodies and vesicles immersed in a fluid. (Doctoral Dissertation). Grenoble Alpes. Retrieved from http://www.theses.fr/2017GREAM042
Chicago Manual of Style (16th Edition):
Jedouaa, Meriem. “Une méthode efficace de capture d'interface pour la simulation de suspensions d'objets rigides et de vésicules immergées dans un fluide : An efficient interface capturing method to simulate dense suspensions of rigid bodies and vesicles immersed in a fluid.” 2017. Doctoral Dissertation, Grenoble Alpes. Accessed March 05, 2021.
http://www.theses.fr/2017GREAM042.
MLA Handbook (7th Edition):
Jedouaa, Meriem. “Une méthode efficace de capture d'interface pour la simulation de suspensions d'objets rigides et de vésicules immergées dans un fluide : An efficient interface capturing method to simulate dense suspensions of rigid bodies and vesicles immersed in a fluid.” 2017. Web. 05 Mar 2021.
Vancouver:
Jedouaa M. Une méthode efficace de capture d'interface pour la simulation de suspensions d'objets rigides et de vésicules immergées dans un fluide : An efficient interface capturing method to simulate dense suspensions of rigid bodies and vesicles immersed in a fluid. [Internet] [Doctoral dissertation]. Grenoble Alpes; 2017. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2017GREAM042.
Council of Science Editors:
Jedouaa M. Une méthode efficace de capture d'interface pour la simulation de suspensions d'objets rigides et de vésicules immergées dans un fluide : An efficient interface capturing method to simulate dense suspensions of rigid bodies and vesicles immersed in a fluid. [Doctoral Dissertation]. Grenoble Alpes; 2017. Available from: http://www.theses.fr/2017GREAM042
INP Toulouse
17.
El Itawi, Hassan.
Crossing of a liquid-liquid interface by a droplet under centrifugal effect for a micro-encapsulation process : Traversée d'une interface liquide-liquide par une goutte sous l'effet centrifuge pour un procédé de micro-encapsulation.
Degree: Docteur es, Dynamique des fluides, 2020, INP Toulouse
URL: http://www.theses.fr/2020INPT0039
► Les applications concernées par la micro-encapsulation ne cessent de croître et couvrent des secteurs d’activités industrielles aussi variés que l’agriculture, la pharmacie, l'industrie alimentaire ou…
(more)
▼ Les applications concernées par la micro-encapsulation ne cessent de croître et couvrent des secteurs d’activités industrielles aussi variés que l’agriculture, la pharmacie, l'industrie alimentaire ou encore la cosmétique. Ce travail s’inscrit dans le développement d’un procédé de micro-encapsulation basé sur des gouttes de taille submillimétrique traversant une interface liquide-liquide sous l’influence d’une force extérieure, ici la force centrifuge. L'objectif de ce travail est de comprendre les mécanismes hydrodynamiques et la dynamique des interfaces avant, pendant et après la traversée d'une interface liquide par une goutte, conduisant à son enrobage. Dans ce but, des approches numériques et expérimentales ont été combinées et complétées par des modèles théoriques. Une méthode numérique résout les équations de Navier-Stokes, discrétisées par une approche en volumes finis, en se basant sur les méthodes « Level-Set » et « Ghost Fluid » pour capturer la dynamique des interfaces en présence et gérer les discontinuités aux interfaces ; elle permet d’accéder au champ de vitesse autour de la goutte déformable lors de la traversée de l’interface. Un dispositif expérimental, permettant de former des gouttes aqueuses de tailles (100-1400 μm) et de forcer leur passage au travers d’une interface liquide grâce à une force centrifuge pouvant atteindre ≈ 2500g, a été conçu afin d’observer toutes les étapes du procédé grâce à une caméra rapide synchronisée avec la rotation de la cellule d'encapsulation, afin d’analyser les conditions de traversée et les différents régimes d’entraînement de fluide. La traversée ou le rebond d’une goutte à l’interface sont fonction de la compétition entre les forces interfaciales, le poids de la goutte et les forces inertielles, et relèvent de phénomènes complexes dépendant de nombreux paramètres adimensionnels. Les deux approches ont permis de définir les conditions de traversée en fonction des nombres adimensionnels pertinents ξ12ξ13 and Bo13, et de développer une loi d'échelle de la longueur maximale de la colonne se formant pendant la traversée ainsi que du volume d’enrobage de la goutte en résultant. Ce travail a permis de déterminer les conditions optimales, à l'échelle d'une inclusion unique, pour encapsuler une goutte selon ce procédé, condition préalable au développement d’un pilote industriel associé à une production en continu.
The applications concerned by microencapsulation are constantly growing and cover sectors of industrial activities as varied as agriculture, pharmacy, food industry and even cosmetics. This work is a part of the development of a microencapsulation process based on sub-millimeter-sized drops crossing a liquid-liquid (L-L) interface under the influence of an external force, in this case centrifugal force. The objective of this work is to understand the hydrodynamics and interface mechanisms before, during and after the passage of a drop through a L-L interface, and leading to its coating. For this purpose, numerical and experimental approaches have been…
Advisors/Committee Members: Le Sauze, Nathalie (thesis director), Massiera, Gladys (thesis director).
Subjects/Keywords: Encapsulation; Écoulement multiphasique; Méthode « Level-Set »; Traversée d’interface; Goutte; Encapsulation; Multiphase flow; Interface crossing; Level-set method; Droplet
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APA ·
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APA (6th Edition):
El Itawi, H. (2020). Crossing of a liquid-liquid interface by a droplet under centrifugal effect for a micro-encapsulation process : Traversée d'une interface liquide-liquide par une goutte sous l'effet centrifuge pour un procédé de micro-encapsulation. (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2020INPT0039
Chicago Manual of Style (16th Edition):
El Itawi, Hassan. “Crossing of a liquid-liquid interface by a droplet under centrifugal effect for a micro-encapsulation process : Traversée d'une interface liquide-liquide par une goutte sous l'effet centrifuge pour un procédé de micro-encapsulation.” 2020. Doctoral Dissertation, INP Toulouse. Accessed March 05, 2021.
http://www.theses.fr/2020INPT0039.
MLA Handbook (7th Edition):
El Itawi, Hassan. “Crossing of a liquid-liquid interface by a droplet under centrifugal effect for a micro-encapsulation process : Traversée d'une interface liquide-liquide par une goutte sous l'effet centrifuge pour un procédé de micro-encapsulation.” 2020. Web. 05 Mar 2021.
Vancouver:
El Itawi H. Crossing of a liquid-liquid interface by a droplet under centrifugal effect for a micro-encapsulation process : Traversée d'une interface liquide-liquide par une goutte sous l'effet centrifuge pour un procédé de micro-encapsulation. [Internet] [Doctoral dissertation]. INP Toulouse; 2020. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2020INPT0039.
Council of Science Editors:
El Itawi H. Crossing of a liquid-liquid interface by a droplet under centrifugal effect for a micro-encapsulation process : Traversée d'une interface liquide-liquide par une goutte sous l'effet centrifuge pour un procédé de micro-encapsulation. [Doctoral Dissertation]. INP Toulouse; 2020. Available from: http://www.theses.fr/2020INPT0039
Uppsala University
18.
Johansson, Niklas.
Implementation of a standard level set method for incompressible two-phase flow simulations.
Degree: Division of Scientific Computing, 2011, Uppsala University
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154651
► The level set method is a powerful way of tracking surfaces by defining the surface as a zero level set of a continuous function…
(more)
▼ The level set method is a powerful way of tracking surfaces by defining the surface as a zero level set of a continuous function that is usually a signed distance function. The level set method is one of the best methods for simulating multi-phase flow because it can easily handle fast topological changes, as well as splitting and merging of fluids. In this thesis, a standard level set method was implemented in C++, using the finite element method library deal.II, to simulate incompressible two-phase flow on some benchmark problems. The results show a significant change of mass in the simulations, something that should not be allowed to happen when simulating incompressible fluids. The mass changes mainly occur in the reinitialization phase, where the level set function is rebuilt to look more like a signed distance function.
Subjects/Keywords: level set method; incompressible two-phase flow; reinitialization; finite element method; deal.II
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APA ·
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APA (6th Edition):
Johansson, N. (2011). Implementation of a standard level set method for incompressible two-phase flow simulations. (Thesis). Uppsala University. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154651
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Johansson, Niklas. “Implementation of a standard level set method for incompressible two-phase flow simulations.” 2011. Thesis, Uppsala University. Accessed March 05, 2021.
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154651.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Johansson, Niklas. “Implementation of a standard level set method for incompressible two-phase flow simulations.” 2011. Web. 05 Mar 2021.
Vancouver:
Johansson N. Implementation of a standard level set method for incompressible two-phase flow simulations. [Internet] [Thesis]. Uppsala University; 2011. [cited 2021 Mar 05].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154651.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Johansson N. Implementation of a standard level set method for incompressible two-phase flow simulations. [Thesis]. Uppsala University; 2011. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154651
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Maryland
19.
Lee, Moon Soo Soo.
DIRECT NUMERICAL SIMULATION OF INCOMPRESSIBLE MULTIPHASE FLOW WITH PHASE CHANGE.
Degree: Mechanical Engineering, 2015, University of Maryland
URL: http://hdl.handle.net/1903/18132
► Phase change problems arise in many practical applications such as air-conditioning and refrigeration, thermal energy storage systems and thermal management of electronic devices. The physical…
(more)
▼ Phase change problems arise in many practical applications such as air-conditioning and refrigeration, thermal energy storage systems and thermal management of electronic devices. The physical phenomenon in such applications are complex and are often difficult to be studied in detail with the help of only experimental techniques. The efforts to improve computational techniques for analyzing two-phase flow problems with phase change are therefore gaining momentum.
The development of numerical methods for multiphase flow has been motivated generally by the need to account more accurately for (a) large topological changes such as phase breakup and merging, (b) sharp representation of the interface and its discontinuous properties and (c) accurate and mass conserving motion of the interface. In addition to these considerations, numerical simulation of multiphase flow with phase change introduces additional challenges related to discontinuities in the velocity and the temperature fields. Moreover, the velocity field is no longer divergence free. For phase change problems, the focus of developmental efforts has thus been on numerically attaining a proper conservation of energy across the interface in addition to the accurate treatment of fluxes of mass and momentum conservation as well as the associated interface advection.
Among the initial efforts related to the simulation of bubble growth in film boiling applications the work in was based on the interface tracking
method using a moving unstructured mesh. That study considered moderate interfacial deformations. A similar problem was subsequently studied using moving, boundary fitted grids , again for regimes of relatively small topological changes. A hybrid interface tracking
method with a moving interface grid overlapping a static Eulerian grid was developed for the computation of a range of phase change problems including, three-dimensional film boiling , multimode two-dimensional pool boiling and film boiling on horizontal cylinders . The handling of interface merging and pinch off however remains a challenge with methods that explicitly track the interface. As large topological changes are crucial for phase change problems, attention has turned in recent years to front capturing methods utilizing implicit interfaces that are more effective in treating complex interface deformations.
The VOF (Volume of Fluid)
method was adopted in to simulate the one-dimensional Stefan problem and the two-dimensional film boiling problem. The approach employed a specific model for mass transfer across the interface involving a mass source term within cells containing the interface. This VOF based approach was further coupled with the
level set method in , employing a smeared-out Heaviside function to avoid the numerical instability related to the source term. The coupled
level set, volume of fluid
method and the diffused interface…
Advisors/Committee Members: Riaz, Amir (advisor), Radermacher, Reinhard (advisor).
Subjects/Keywords: Mechanical engineering; CFD; Heat transfer; Level set method; Multiphase; Numerical method; Phase change
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APA ·
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APA (6th Edition):
Lee, M. S. S. (2015). DIRECT NUMERICAL SIMULATION OF INCOMPRESSIBLE MULTIPHASE FLOW WITH PHASE CHANGE. (Thesis). University of Maryland. Retrieved from http://hdl.handle.net/1903/18132
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lee, Moon Soo Soo. “DIRECT NUMERICAL SIMULATION OF INCOMPRESSIBLE MULTIPHASE FLOW WITH PHASE CHANGE.” 2015. Thesis, University of Maryland. Accessed March 05, 2021.
http://hdl.handle.net/1903/18132.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lee, Moon Soo Soo. “DIRECT NUMERICAL SIMULATION OF INCOMPRESSIBLE MULTIPHASE FLOW WITH PHASE CHANGE.” 2015. Web. 05 Mar 2021.
Vancouver:
Lee MSS. DIRECT NUMERICAL SIMULATION OF INCOMPRESSIBLE MULTIPHASE FLOW WITH PHASE CHANGE. [Internet] [Thesis]. University of Maryland; 2015. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1903/18132.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lee MSS. DIRECT NUMERICAL SIMULATION OF INCOMPRESSIBLE MULTIPHASE FLOW WITH PHASE CHANGE. [Thesis]. University of Maryland; 2015. Available from: http://hdl.handle.net/1903/18132
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Waterloo
20.
Geiger, Paul.
Simulation of In-Flight Rime Icing Using a Non-Body-Fitted Mesh.
Degree: 2020, University of Waterloo
URL: http://hdl.handle.net/10012/15810
► In-flight rime icing occurs when supercooled droplets strike the surface of an aircraft and instantly freeze. This often occurs in the high moisture, cold environments…
(more)
▼ In-flight rime icing occurs when supercooled droplets strike the surface of an aircraft and instantly freeze. This often occurs in the high moisture, cold environments of clouds and is of major concern to aircraft manufacturers and pilots due to safety issues, as the icing degrades the aerodynamic performance of the plane. Rime icing models are important in their own right and as a step towards more complex glaze ice/mixed ice models.
Most current commercially available software use boundary-fitted approaches to the air and droplet phases along with a node-displacement method for the boundary. This can cause issues as the node-displacement approach to the boundary can cause tangles in the boundary which are unphysical, and the boundary-fitted methodologies require remeshing after each ice accretion step which can degrade mesh quality and cause crashes.
The goal of this thesis is to create a non-boundary-fitted approach towards rime icing simulations. Level set methodologies, which are unsusceptible to tangles, are used to handle the evolution of the boundaries. Static meshes which are Cartesian in the vicinity of the boundary are used, and high Reynolds wall functions are incorporated into the methodology so that the meshes can be made coarser and solutions can be reached faster. This proposed model is implemented via modifications of the OpenFOAM® 5.0 open-source environment. Where possible, results are compared to experimental results and to the commercially available FENSAP-ICE software by ANSYS, Inc.
Immersed boundary and cut-cell methodologies are explored for the droplets near the boundary. It was found that the developed cut-cell methodology is about twice as accurate as the immersed boundary method developed and that this is one of the dominant discretization errors in many tests.
It was shown that as droplet size goes down, particularly below 10 μm, differences in-between the FENSAP-ICE and the proposed model start increasing, with the total collection efficiency going from 0.2% different in-between the models for droplets of size 35.52 μm up to as much as 300% for 4.96 μm, and it is suggested that modifications to the model and discretization be made before tests for sub-10 μm mean-value droplet diameter (MVD) are run, although these tend to be rarely encountered in nature as most droplets tend to range from 10-50 μm. For simulation using a MVD of 16 μm and a 7-bin Langmuir-D distribution, it was found that the model differed in total collection predictions from FENSAP-ICE by 0.8%, and by 2.9% using just the MVD, as the smallest droplets contribute very little to the net collection.
Using a pseudo-steady-state, multistep icing procedure, it was found that over a NACA23012 airfoil at a 2⁰ angle of attack, the total accreted ice for a 1-step ice accretion differed by 0.21% from FENSAP-ICE results, and for a 4-step test, it differed by 0.11% with similar resultant ice shapes when a developed model for the ending time-step which increases the global conservation was used, and by 17% for a 1-step…
Subjects/Keywords: in-flight icing; rime icing; immersed boundary method; cut-cell method; finite volume method; level set method; non-body-fitted mesh
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APA ·
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APA (6th Edition):
Geiger, P. (2020). Simulation of In-Flight Rime Icing Using a Non-Body-Fitted Mesh. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/15810
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Geiger, Paul. “Simulation of In-Flight Rime Icing Using a Non-Body-Fitted Mesh.” 2020. Thesis, University of Waterloo. Accessed March 05, 2021.
http://hdl.handle.net/10012/15810.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Geiger, Paul. “Simulation of In-Flight Rime Icing Using a Non-Body-Fitted Mesh.” 2020. Web. 05 Mar 2021.
Vancouver:
Geiger P. Simulation of In-Flight Rime Icing Using a Non-Body-Fitted Mesh. [Internet] [Thesis]. University of Waterloo; 2020. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/10012/15810.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Geiger P. Simulation of In-Flight Rime Icing Using a Non-Body-Fitted Mesh. [Thesis]. University of Waterloo; 2020. Available from: http://hdl.handle.net/10012/15810
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
21.
Herichon, Eliam.
Modélisation et simulation du déplacement de corps indéformables dans les écoulements diphasiques : Modelling and Simulation of the effects of a moving body in multiphase compressible flows.
Degree: Docteur es, Mécanique et Physique des Fluides, 2014, Aix Marseille Université
URL: http://www.theses.fr/2014AIXM4768
► Ces travaux portent sur la modélisation et la simulation numérique des effets du déplacement d'un corps indéformable dans un écoulement multiphasique compressible. Ils se placent…
(more)
▼ Ces travaux portent sur la modélisation et la simulation numérique des effets du déplacement d'un corps indéformable dans un écoulement multiphasique compressible. Ils se placent dans le cas où plusieurs objets sont en mouvement ou dans le cas où un objet est en mouvement dans un milieu aux géométries complexes. L'étude ne peut alors pas être placée dans le référentiel lié à l'objet en mouvement. Le modèle est basé sur une méthode multiphasique à interfaces diffuses où les différentes phases sont en équilibre mécanique. Le système régissant l'écoulement fluide est augmenté d'une équation d'advection. Cette dernière s'applique sur une fonction Level Set dont le niveau zéro permet de localiser le mobile dans l'espace. Des termes de couplage sont ajoutés au membre de droite des équations d'évolution de la quantité de mouvement et de l'énergie totale. Ces termes sont composés d'un facteur du type pénalisation et d'un facteur du type relaxation de vitesses. Cette nouvelle méthode permet de simuler des cas complexes où peuvent interagir des mobiles à hautes vitesses, des ondes de choc et des interfaces liquide/gaz.
This work deals with modelling and the numerical simulation of the effects of a moving rigid body on a multiphase flow. Here more than one object is moving, or an object is moving in a complex geometry domain. So the reference frame linked to the moving body can't be used. The model is build on a multiphase diffuse interface method with mechanical equilibrium. An advection equation is added. It applies on a Level Set function used to track the moving body. Coupling terms are added to the momentum equation and to the total energy equation. These terms are made of a penalization factor and a velocity relaxation factor. This new method allows to simulate complex cases where can interact high velocity objects, shock waves and liquid / gas interfaces.
Advisors/Committee Members: Saurel, Richard (thesis director).
Subjects/Keywords: Écoulements diphasiques; Méthode Level Set; Méthode de relaxation; Ghost Cell; Frontières immergées; Modélisation; Simulation numérique; Multiphase flows; Level Set method; Relaxation method; Ghost Cell method; Immersed Boundaries; Modelisation; Numerical simulation
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APA ·
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APA (6th Edition):
Herichon, E. (2014). Modélisation et simulation du déplacement de corps indéformables dans les écoulements diphasiques : Modelling and Simulation of the effects of a moving body in multiphase compressible flows. (Doctoral Dissertation). Aix Marseille Université. Retrieved from http://www.theses.fr/2014AIXM4768
Chicago Manual of Style (16th Edition):
Herichon, Eliam. “Modélisation et simulation du déplacement de corps indéformables dans les écoulements diphasiques : Modelling and Simulation of the effects of a moving body in multiphase compressible flows.” 2014. Doctoral Dissertation, Aix Marseille Université. Accessed March 05, 2021.
http://www.theses.fr/2014AIXM4768.
MLA Handbook (7th Edition):
Herichon, Eliam. “Modélisation et simulation du déplacement de corps indéformables dans les écoulements diphasiques : Modelling and Simulation of the effects of a moving body in multiphase compressible flows.” 2014. Web. 05 Mar 2021.
Vancouver:
Herichon E. Modélisation et simulation du déplacement de corps indéformables dans les écoulements diphasiques : Modelling and Simulation of the effects of a moving body in multiphase compressible flows. [Internet] [Doctoral dissertation]. Aix Marseille Université 2014. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2014AIXM4768.
Council of Science Editors:
Herichon E. Modélisation et simulation du déplacement de corps indéformables dans les écoulements diphasiques : Modelling and Simulation of the effects of a moving body in multiphase compressible flows. [Doctoral Dissertation]. Aix Marseille Université 2014. Available from: http://www.theses.fr/2014AIXM4768
Delft University of Technology
22.
Shen, Zhongwei (author).
Vertical Motion Simulation Of A DTMB 5415M Ship In Head Sea Using The Variational Multi-scale Method.
Degree: 2019, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:cbbf426b-451e-4a40-835b-0a348a88e41d
► This master thesis presents the computation of free-surface flow phenomena with emphasis on ship hydromechanics. We perform a simulation of the heave and the pitch…
(more)
▼ This master thesis presents the computation of free-surface flow phenomena with emphasis on ship hydromechanics. We perform a simulation of the heave and the pitch motion of the DTMB 5415M ship moving in head sea. To this purpose we employ an existing Arbitrary-Lagrangian-Eulerian residual-based variational multiscale method (ALE-RBVMS) to discretize the incompressible Navier-Stokes equations and use the level-set method to capture the interface. We validate the numerical results obtained from the ALE-RBVMS computation with experimental data. We show that these results significantly improve upon those acquired from other CFD codes. This demonstrates the viability of the framework for simulations in ship hydromechanics.
Ship Hydrodynamics
Advisors/Committee Members: Akkerman, Ido (mentor), ten Eikelder, Marco (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: RBVMS; CFD; Level Set Method; ALE Method; Free Surface; Ship motion; DTMB 5415M; Finite Element Analysis; variational multiscale method
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APA (6th Edition):
Shen, Z. (. (2019). Vertical Motion Simulation Of A DTMB 5415M Ship In Head Sea Using The Variational Multi-scale Method. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:cbbf426b-451e-4a40-835b-0a348a88e41d
Chicago Manual of Style (16th Edition):
Shen, Zhongwei (author). “Vertical Motion Simulation Of A DTMB 5415M Ship In Head Sea Using The Variational Multi-scale Method.” 2019. Masters Thesis, Delft University of Technology. Accessed March 05, 2021.
http://resolver.tudelft.nl/uuid:cbbf426b-451e-4a40-835b-0a348a88e41d.
MLA Handbook (7th Edition):
Shen, Zhongwei (author). “Vertical Motion Simulation Of A DTMB 5415M Ship In Head Sea Using The Variational Multi-scale Method.” 2019. Web. 05 Mar 2021.
Vancouver:
Shen Z(. Vertical Motion Simulation Of A DTMB 5415M Ship In Head Sea Using The Variational Multi-scale Method. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 05].
Available from: http://resolver.tudelft.nl/uuid:cbbf426b-451e-4a40-835b-0a348a88e41d.
Council of Science Editors:
Shen Z(. Vertical Motion Simulation Of A DTMB 5415M Ship In Head Sea Using The Variational Multi-scale Method. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:cbbf426b-451e-4a40-835b-0a348a88e41d
23.
Takagi, Kentaro.
Numerical investigation of two-frequency forced Faraday waves : 2周波数加振のファラデー波の数値的研究.
Degree: 博士(理学), 2015, Kyoto University / 京都大学
URL: http://hdl.handle.net/2433/199090
;
http://dx.doi.org/10.14989/doctor.k18781
新制・課程博士
甲第18781号
理博第4039号
Subjects/Keywords: Faraday waves; level-set method; particle level-set method; rhomboidal pattern
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APA (6th Edition):
Takagi, K. (2015). Numerical investigation of two-frequency forced Faraday waves : 2周波数加振のファラデー波の数値的研究. (Thesis). Kyoto University / 京都大学. Retrieved from http://hdl.handle.net/2433/199090 ; http://dx.doi.org/10.14989/doctor.k18781
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Takagi, Kentaro. “Numerical investigation of two-frequency forced Faraday waves : 2周波数加振のファラデー波の数値的研究.” 2015. Thesis, Kyoto University / 京都大学. Accessed March 05, 2021.
http://hdl.handle.net/2433/199090 ; http://dx.doi.org/10.14989/doctor.k18781.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Takagi, Kentaro. “Numerical investigation of two-frequency forced Faraday waves : 2周波数加振のファラデー波の数値的研究.” 2015. Web. 05 Mar 2021.
Vancouver:
Takagi K. Numerical investigation of two-frequency forced Faraday waves : 2周波数加振のファラデー波の数値的研究. [Internet] [Thesis]. Kyoto University / 京都大学; 2015. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/2433/199090 ; http://dx.doi.org/10.14989/doctor.k18781.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Takagi K. Numerical investigation of two-frequency forced Faraday waves : 2周波数加振のファラデー波の数値的研究. [Thesis]. Kyoto University / 京都大学; 2015. Available from: http://hdl.handle.net/2433/199090 ; http://dx.doi.org/10.14989/doctor.k18781
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
24.
Lepilliez, Mathieu.
Simulation numérique des ballotements d'ergols dans les réservoirs de satellites en microgravité et à faible nombre de Bond : Numerical modeling of sloshing of ergols in satellite tanks under microgravity conditions, and at low Bond numbers.
Degree: Docteur es, Dynamique des fluides, 2015, Université Toulouse III – Paul Sabatier
URL: http://www.theses.fr/2015TOU30248
► Cette thèse porte sur l'étude des ballotements dans les réservoirs de satellites à poste, lors des phases de manoeuvre à faible accélération. En effet la…
(more)
▼ Cette thèse porte sur l'étude des ballotements dans les réservoirs de satellites à poste, lors des phases de manoeuvre à faible accélération. En effet la bulle de gaz d'hélium servant à pressuriser le réservoir se met en mouvement, générant ainsi des perturbations sur la stabilité globale du satellite. Afin de mener à bien cette étude, des méthodes numériques ont été développées, avec une méthode de frontières immergées pour prendre en compte les parois du réservoir.Le code est utilise la méthode Level-Set pour capturer l'interface, et gère les sauts à l'aide de la méthode Ghost-Fluid. Un solveur BlackBox Multigrid est également développé pour améliorer lesperformances de calcul. Une étude est présentée dans le dernier chapitre pour définir quelques lois de comportements en fonction des vitesses et accélérations générées lors des manoeuvres.
The core study of this PhD thesis is the sloshing in satellite tanks, during low acceleration maneuvers. Indeed the helium bubble used to pressurize the tank moves, thus generating perturbations on the global stability of the satellite. In order to understand this problem, numerical schemes have been developed, such as an immersed boundary method to model the tank wall. The numerical tool uses a Level-Set function coupled to a Ghost Fluid Method to track the interface and to account for the jump conditions.A BlackBox Multigrid Solver have been developed to improve computational cost. Finally a study is presented in the last chapter to predict the behaviour of the fluids with a varying rotational speed generated during some classical maneuvers.
Advisors/Committee Members: Tanguy, Sébastien (thesis director).
Subjects/Keywords: Ecoulements diphasiques; Lignes triples; Frontières Immergées; Level-Set; Ghost Fluid Method; BlackBox Multigrid; Multiphase Flows; Contact lines; Immersed Interface Methods; Level-Set; Ghost Fluid Method; BlackBox Multigrid
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APA (6th Edition):
Lepilliez, M. (2015). Simulation numérique des ballotements d'ergols dans les réservoirs de satellites en microgravité et à faible nombre de Bond : Numerical modeling of sloshing of ergols in satellite tanks under microgravity conditions, and at low Bond numbers. (Doctoral Dissertation). Université Toulouse III – Paul Sabatier. Retrieved from http://www.theses.fr/2015TOU30248
Chicago Manual of Style (16th Edition):
Lepilliez, Mathieu. “Simulation numérique des ballotements d'ergols dans les réservoirs de satellites en microgravité et à faible nombre de Bond : Numerical modeling of sloshing of ergols in satellite tanks under microgravity conditions, and at low Bond numbers.” 2015. Doctoral Dissertation, Université Toulouse III – Paul Sabatier. Accessed March 05, 2021.
http://www.theses.fr/2015TOU30248.
MLA Handbook (7th Edition):
Lepilliez, Mathieu. “Simulation numérique des ballotements d'ergols dans les réservoirs de satellites en microgravité et à faible nombre de Bond : Numerical modeling of sloshing of ergols in satellite tanks under microgravity conditions, and at low Bond numbers.” 2015. Web. 05 Mar 2021.
Vancouver:
Lepilliez M. Simulation numérique des ballotements d'ergols dans les réservoirs de satellites en microgravité et à faible nombre de Bond : Numerical modeling of sloshing of ergols in satellite tanks under microgravity conditions, and at low Bond numbers. [Internet] [Doctoral dissertation]. Université Toulouse III – Paul Sabatier; 2015. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2015TOU30248.
Council of Science Editors:
Lepilliez M. Simulation numérique des ballotements d'ergols dans les réservoirs de satellites en microgravité et à faible nombre de Bond : Numerical modeling of sloshing of ergols in satellite tanks under microgravity conditions, and at low Bond numbers. [Doctoral Dissertation]. Université Toulouse III – Paul Sabatier; 2015. Available from: http://www.theses.fr/2015TOU30248
Université de Lorraine
25.
Bencheikh, Issam.
Simulation multi-étapes de l’usure des outils de coupe revêtus par une modélisation XFEM/Level-set : Multi-step simulation of coated cutting tools wear with XFEM/Level-set modelling.
Degree: Docteur es, Mécanique et énergétique, 2018, Université de Lorraine
URL: http://www.theses.fr/2018LORR0094
► Lors de l'opération d’usinage à grande vitesse, la résistance à l'usure des outils de coupe est améliorée par l’utilisation des revêtements mono ou multicouches sur…
(more)
▼ Lors de l'opération d’usinage à grande vitesse, la résistance à l'usure des outils de coupe est améliorée par l’utilisation des revêtements mono ou multicouches sur les faces actives de l’outil. Cependant, le chargement thermomécanique généré à l'interface outil-pièce affecte considérablement les zones de contact. Par cet effet, plusieurs modes d'usure tels que la fissuration, l’abrasion, l’adhésion et le délaminage du revêtement peuvent se manifester. L'étude du comportement des revêtements et de leurs différents modes de dégradation permet de mieux comprendre leur impact sur la durée de vie de l'outil et ainsi optimiser le procédé d'usinage. Dans ce travail de thèse, une approche numérique multi-étapes a été proposée pour prédire l'usure des outils de coupe revêtus. Cette approche est composée par trois principales étapes. La première consiste à effectuer une simulation éléments finis de l’usinage pour une courte durée (jusqu’à la stabilisation du chargement à l’interface outil/pièce). La deuxième étape consiste à récupérer ce chargement et de l’utiliser comme une entrée du modèle XFEM/Level-set. Ce dernier permet d’analyser le comportement des couches de revêtement sans recours à un maillage conforme aux interfaces. Par conséquence, la distorsion du maillage est évitée lorsque le profil d'outil usé est mis à jour, ainsi que le temps de calcul CPU est drastiquement réduit. La dernière étape de cette approche consiste à calculer le taux d’usure et ainsi prédire le déplacement des nœuds de l’outil de coupe affectés par l’usure. Les essais expérimentaux ont permis d’une part d’identifier les paramètres de contact outil/pièce, et d’autre part de valider l’approche proposée
In high speed machining, wear resistance of the cutting tools is improved by depositing single or multilayered coatings on their surface. However, the thermomechanical loading generated at the tool-workpiece interface greatly affects the contact zones. For this purpose, several wear modes such as cracking, abrasion, adhesion and delamination of the coating can be occurred. The study of the coatings behavior and their different degradation modes lead to better understanding of their impact on the tool life and machining process under optimal conditions. In this PhD thesis work, a multi-step numerical approach has been proposed to predict wear of the coated cutting tools. This approach involves three main steps. The first is to perform a finite element simulation of the orthogonal cutting for a short time (until the loading stabilization at the tool/workpiece interface). The second step is to recover this loading and use it as an input for the XFEM/Level-set model. The latter allow to take into account the coating layers presence without any need of mesh conforming to the interfaces. As a result, the mesh distortion is avoided when the worn tool profile is updated, as well as the CPU calculation time is drastically reduced. The final step of this approach is to convert the wear rate equation into a nodal displacement, thus representing the cutting…
Advisors/Committee Members: Nouari, Mohammed (thesis director).
Subjects/Keywords: Usinage; Revêtement; EXtended Finite Element Method; Level set; Usure; Comportement thermomécanique transitoire; Machining; Coating; EXtended Finite Element Method; Level set; Wear; Transient thermomechanical behavior; 621.89
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APA ·
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APA (6th Edition):
Bencheikh, I. (2018). Simulation multi-étapes de l’usure des outils de coupe revêtus par une modélisation XFEM/Level-set : Multi-step simulation of coated cutting tools wear with XFEM/Level-set modelling. (Doctoral Dissertation). Université de Lorraine. Retrieved from http://www.theses.fr/2018LORR0094
Chicago Manual of Style (16th Edition):
Bencheikh, Issam. “Simulation multi-étapes de l’usure des outils de coupe revêtus par une modélisation XFEM/Level-set : Multi-step simulation of coated cutting tools wear with XFEM/Level-set modelling.” 2018. Doctoral Dissertation, Université de Lorraine. Accessed March 05, 2021.
http://www.theses.fr/2018LORR0094.
MLA Handbook (7th Edition):
Bencheikh, Issam. “Simulation multi-étapes de l’usure des outils de coupe revêtus par une modélisation XFEM/Level-set : Multi-step simulation of coated cutting tools wear with XFEM/Level-set modelling.” 2018. Web. 05 Mar 2021.
Vancouver:
Bencheikh I. Simulation multi-étapes de l’usure des outils de coupe revêtus par une modélisation XFEM/Level-set : Multi-step simulation of coated cutting tools wear with XFEM/Level-set modelling. [Internet] [Doctoral dissertation]. Université de Lorraine; 2018. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2018LORR0094.
Council of Science Editors:
Bencheikh I. Simulation multi-étapes de l’usure des outils de coupe revêtus par une modélisation XFEM/Level-set : Multi-step simulation of coated cutting tools wear with XFEM/Level-set modelling. [Doctoral Dissertation]. Université de Lorraine; 2018. Available from: http://www.theses.fr/2018LORR0094
26.
Canu, Romain.
Développement d'une méthode compressible avec évaporation pour la simulation d'interface résolue dans le cadre de l'atomisation. : Development of a compressible method with vaporisation for the simulation of resolved interface in the atomisation context.
Degree: Docteur es, Physique, 2019, Normandie
URL: http://www.theses.fr/2019NORMR016
► Cette thèse montre le développement d’un code de calcul pour les simulations numériques directes d’écoulements diphasiques compressibles avec évaporation. Un couplage entre les méthodes Level…
(more)
▼ Cette thèse montre le développement d’un code de calcul pour les simulations numériques directes d’écoulements diphasiques compressibles avec évaporation. Un couplage entre les méthodes Level Set et VOF est réalisé pour le suivi d’interface. Afin de résoudre les équations de la mécanique des fluides, une méthode basée sur la pression est employée et, pour découpler la vitesse de la pression, une méthode de projection est effectuée. Cette méthode permet l’implicitation des termes liés à l’acoustique et donc de diminuer la contrainte sur le pas de temps. Le liquide et le gaz sont traités de manière compressible permettant des variations locales des masses volumiques grâce à l’utilisation d’équations d’état. L’évaporation est simulée de deux manières différentes ; une première, où un taux d’évaporation constant est employé et une seconde, où ce taux est calculé par la thermique. Parallèlement à ce sujet, une étude de la distribution des courbures dans une injection de liquide est réalisée. Cette étude permet d’étendre le concept de distribution des tailles de gouttes dans un spray et d’améliorer les informations disponibles dans le modèle ELSA. Enfin, une autre étude est effectuée sur la recherche d’un critère, basé sur les courbures à l’interface, pour estimer la qualité d’une simulation.
This PhD thesis shows the development of a numerical method for solving two-phase flows with vaporisation. A coupling between Level Set and VOF methods is realised for the interface capturing. In order to solve fluid mechanics equations, a pressure based method is employed and, to decouple velocity and pressure, a projection method is performed. This method allows the implicitation of the acoustic terms and the time step constraint reduction. Liquid and gas are considered as compressible allowing local density variations with equations of state. The vaporisation is computed in two different ways ; a first one where the vaporisation rate is constant and a second one, where this rate is calculated by thermodynamics. Along with this topic, a study on curvature distribution in a liquid injection configuration is realised. This study allows to extend the drop size distribution concept in a spray and to improve available informations on ELSA model. Finally, an other study is performed on thedevelopment of a criterion, based on interface curvatures, which estimates the quality of a simulation.
Advisors/Committee Members: Demoulin, François-Xavier (thesis director).
Subjects/Keywords: Simulation numérique directe; Méthode Level Set; Méthode VOF; Mécanique des fluides; Atomisation; Transitions de phases; Direct numerical simulation; Level set method; VOF method; Fluid mechanics; Atomisation; Phase transitions; 532.5
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APA ·
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APA (6th Edition):
Canu, R. (2019). Développement d'une méthode compressible avec évaporation pour la simulation d'interface résolue dans le cadre de l'atomisation. : Development of a compressible method with vaporisation for the simulation of resolved interface in the atomisation context. (Doctoral Dissertation). Normandie. Retrieved from http://www.theses.fr/2019NORMR016
Chicago Manual of Style (16th Edition):
Canu, Romain. “Développement d'une méthode compressible avec évaporation pour la simulation d'interface résolue dans le cadre de l'atomisation. : Development of a compressible method with vaporisation for the simulation of resolved interface in the atomisation context.” 2019. Doctoral Dissertation, Normandie. Accessed March 05, 2021.
http://www.theses.fr/2019NORMR016.
MLA Handbook (7th Edition):
Canu, Romain. “Développement d'une méthode compressible avec évaporation pour la simulation d'interface résolue dans le cadre de l'atomisation. : Development of a compressible method with vaporisation for the simulation of resolved interface in the atomisation context.” 2019. Web. 05 Mar 2021.
Vancouver:
Canu R. Développement d'une méthode compressible avec évaporation pour la simulation d'interface résolue dans le cadre de l'atomisation. : Development of a compressible method with vaporisation for the simulation of resolved interface in the atomisation context. [Internet] [Doctoral dissertation]. Normandie; 2019. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2019NORMR016.
Council of Science Editors:
Canu R. Développement d'une méthode compressible avec évaporation pour la simulation d'interface résolue dans le cadre de l'atomisation. : Development of a compressible method with vaporisation for the simulation of resolved interface in the atomisation context. [Doctoral Dissertation]. Normandie; 2019. Available from: http://www.theses.fr/2019NORMR016
Pontifical Catholic University of Rio de Janeiro
27.
BRUNO NIECKELE AZEVEDO.
[en] FLOW OF TWO DROPS THROUGH A STRAIGHT
MICROCAPILLARY.
Degree: 2014, Pontifical Catholic University of Rio de Janeiro
URL: http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23533
► [pt] Emulsões podem ser usadas como agentes de controle de mobilidade em métodos de recuperação avançada de óleo de forma a conseguir um varrido mais…
(more)
▼ [pt] Emulsões podem ser usadas como agentes de
controle de mobilidade em métodos de recuperação avançada de óleo
de forma a conseguir um varrido mais eficiente do reservatório. A
aplicação de tal técnica requer um entendimento completo de como as
emulsões escoam em um material poroso. O comportamento macroscópico
do escoamento deve ser determinado baseado no escoamento na escala
de poros, em que as emulsões não podem ser tratadas como líquidos
não Newtonianos monofásicos, uma vez que os diâmetros das gotas são
da mesma ordem de magnitude das gargantas de poros. Experimentos
realizados por Cobos et al.(1) sobre o escoamento de emulsões
através de micro-capilares com garganta, que serviu como modelo
para a geometria de uma garganta de poro conectando dois poros
adjacentes, mostrou o efeito da fase dispersa na queda de pressão
para diferentes condições de escoamento e características das
emulsõs. De forma a ampliar a faixa de número de capilaridade e
tamanhos de gota explorados nos experimentos, determinar o efeito
da tensão interfacial, razão de viscosidades, geometria do capilar
e determinar características do escoamento com mais de uma gota, é
estudado o escoamento de gotas suspensas em uma fase contínua
escoando através de um micro-capilar. A evolução da interface das
gotas é determinada pelo método de level-set, que é acoplado a
solução das equações de Navier Stokes, baseada no método de
elementos finitos. Foi investigado o efeito da distância inicial
entre duas gotas, assim como o efeito da tensão interfacial na
velocidade de cada uma das gotas. Os resultados obtidos fornecem
uma descrição mais detalhada do escoamento de emulsões em gargantas
de poros.
[en] Emulsions can be used as mobility control agent
in enhanced oil recovery methods in order to achieve a more
efficient sweep of the reservoir. The application of such technique
requires full understanding of how emulsions flow in a porous
material. The macroscopic flow behavior can be determined based on
the pore scale flow, at which emulsions cannot be treated as a
single phase non Newtonian liquid, since the drop diameters are in
the same order of magnitude of the pore throats. Experiments by
Cobos et al.(1) of flow of emulsions through constricted micro
capillaries, wich served as a model to the geometry of a pore
throat connecting two adjacent pore bodies, have shown the effect
of the dispersed phase on the pressure drop for different flow
conditions and emulsions characteristics. In order to widen the
range of capillary number and drop size explored in the experiments
and to determine the effect of interfacial tension, viscosity
ratio, capillary geometry and determine the characteristics of the
flow with more the one drop, we study the flow of a drops suspended
in a continuous phase flowing through a constricted micro
capillary. The evolution of the drop interface is determined by the
level set method which is incorporated to a fully coupled implicit
Navier Stokes solver based finite element method. We investigate
the effect of an initial distance…
Advisors/Committee Members: MARCIO DA SILVEIRA CARVALHO.
Subjects/Keywords: [pt] EMULSOES; [en] EMULSIONS; [pt] METODO DE ELEMENTOS FINITOS; [en] FINITE ELEMENT METHOD; [pt] METODO DE LEVEL SET; [en] LEVEL SET METHOD; [pt] MICRO HIDRODINAMICA; [en] CAPILLARY HYDRODYNAMICS
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APA ·
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MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
AZEVEDO, B. N. (2014). [en] FLOW OF TWO DROPS THROUGH A STRAIGHT
MICROCAPILLARY. (Thesis). Pontifical Catholic University of Rio de Janeiro. Retrieved from http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23533
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
AZEVEDO, BRUNO NIECKELE. “[en] FLOW OF TWO DROPS THROUGH A STRAIGHT
MICROCAPILLARY.” 2014. Thesis, Pontifical Catholic University of Rio de Janeiro. Accessed March 05, 2021.
http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23533.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
AZEVEDO, BRUNO NIECKELE. “[en] FLOW OF TWO DROPS THROUGH A STRAIGHT
MICROCAPILLARY.” 2014. Web. 05 Mar 2021.
Vancouver:
AZEVEDO BN. [en] FLOW OF TWO DROPS THROUGH A STRAIGHT
MICROCAPILLARY. [Internet] [Thesis]. Pontifical Catholic University of Rio de Janeiro; 2014. [cited 2021 Mar 05].
Available from: http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23533.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
AZEVEDO BN. [en] FLOW OF TWO DROPS THROUGH A STRAIGHT
MICROCAPILLARY. [Thesis]. Pontifical Catholic University of Rio de Janeiro; 2014. Available from: http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23533
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
28.
Cappanera, Loïc.
Stabilisation non linéaire des équations de la magnétohydrodynamique et applications aux écoulements multiphasiques : Nonlinear stabilization of magnetohydrodynamic equations and applications to multiphase flows.
Degree: Docteur es, Mécanique des fluides, 2015, Université Paris-Saclay (ComUE)
URL: http://www.theses.fr/2015SACLS149
► Les travaux présentés dans ce manuscrit se concentrent sur l'approximation numérique des équations de la magnétohydrodynamique (MHD) et sur leur stabilisation pour des problèmes caractérisés…
(more)
▼ Les travaux présentés dans ce manuscrit se concentrent sur l'approximation numérique des équations de la magnétohydrodynamique (MHD) et sur leur stabilisation pour des problèmes caractérisés par des nombres de Reynolds cinétique élevés ou par des écoulements multiphasiques. Nous validons numériquement un nouveau modèle de Simulation des Grandes Echelles (ou Large Eddy Simulations, LES), dit de viscosité entropique, sur des écoulements de cylindre en précession ou créés par des turbines contra-rotatives (écoulement de Von Kármán). Ces études sont réalisées avec le code MHD SFEMaNS développé par J.-L. Guermond et C. Nore depuis 2002 pour des géométries axisymétriques. Ce code est basé sur une décomposition spectrale dans la direction azimutale et des éléments finis de Lagrange dans un plan méridien. Nous adaptons une méthode de pseudo-pénalisation pour prendre en compte des turbines en mouvement, ce qui étend le code SFEMaNS à des géométries quelconques. Nous présentons aussi une méthode originale d'approximation des équations de Navier-Stokes à densité variable qui utilise la quantité de mouvement comme variable et la viscosité entropique pour stabiliser les équations de la masse et du mouvement.
The investigations presented in this manuscript focus on the numerical approximation of the magnetohydrodynamics (MHD) equations and on their stabilization for problems involving either large kinetic Reynolds numbers or multiphase flows. We validate numerically a new Large Eddy Simulation (LES) model, called entropy viscosity, on flows driven by precessing cylindrical containers or counter-rotating impellers (Von Kármán flow). These studies are performed with SFEMaNS MHD-code developed by J.-L. Guermond and C. Nore since 2002 for axisymmetric geometries. This code is based on a spectral decomposition in the azimuthal direction and a Lagrange finite element approximation in a meridian plane. We adapt a pseudo-penalization method to report the action of rotating impellers that extends the range of SFEMaNS's applications to any geometry. We also present an original approximation method of the Navier-Stokes equations with variable density. This method uses the momentum as variable and stabilizes both mass and momentum equations with the same entropy viscosity.
Advisors/Committee Members: Nore, Caroline (thesis director).
Subjects/Keywords: Écoulements multiphasiques; Viscosité entropique; Méthode de pseudo-Penalisation; Méthode level set; Magnétohydrodynamique; Mutliphase flow; Entropy viscosity; Pseudo-Penalization method; Level set method; Magnetohydrodynamics
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APA (6th Edition):
Cappanera, L. (2015). Stabilisation non linéaire des équations de la magnétohydrodynamique et applications aux écoulements multiphasiques : Nonlinear stabilization of magnetohydrodynamic equations and applications to multiphase flows. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2015SACLS149
Chicago Manual of Style (16th Edition):
Cappanera, Loïc. “Stabilisation non linéaire des équations de la magnétohydrodynamique et applications aux écoulements multiphasiques : Nonlinear stabilization of magnetohydrodynamic equations and applications to multiphase flows.” 2015. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed March 05, 2021.
http://www.theses.fr/2015SACLS149.
MLA Handbook (7th Edition):
Cappanera, Loïc. “Stabilisation non linéaire des équations de la magnétohydrodynamique et applications aux écoulements multiphasiques : Nonlinear stabilization of magnetohydrodynamic equations and applications to multiphase flows.” 2015. Web. 05 Mar 2021.
Vancouver:
Cappanera L. Stabilisation non linéaire des équations de la magnétohydrodynamique et applications aux écoulements multiphasiques : Nonlinear stabilization of magnetohydrodynamic equations and applications to multiphase flows. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2015. [cited 2021 Mar 05].
Available from: http://www.theses.fr/2015SACLS149.
Council of Science Editors:
Cappanera L. Stabilisation non linéaire des équations de la magnétohydrodynamique et applications aux écoulements multiphasiques : Nonlinear stabilization of magnetohydrodynamic equations and applications to multiphase flows. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2015. Available from: http://www.theses.fr/2015SACLS149
Kyoto University
29.
Takagi, Kentaro.
Numerical investigation of two-frequency forced Faraday waves
.
Degree: 2015, Kyoto University
URL: http://hdl.handle.net/2433/199090
Subjects/Keywords: Faraday waves;
level-set method;
particle level-set method;
rhomboidal pattern
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Record Details
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❌
APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Takagi, K. (2015). Numerical investigation of two-frequency forced Faraday waves
. (Thesis). Kyoto University. Retrieved from http://hdl.handle.net/2433/199090
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Takagi, Kentaro. “Numerical investigation of two-frequency forced Faraday waves
.” 2015. Thesis, Kyoto University. Accessed March 05, 2021.
http://hdl.handle.net/2433/199090.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Takagi, Kentaro. “Numerical investigation of two-frequency forced Faraday waves
.” 2015. Web. 05 Mar 2021.
Vancouver:
Takagi K. Numerical investigation of two-frequency forced Faraday waves
. [Internet] [Thesis]. Kyoto University; 2015. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/2433/199090.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Takagi K. Numerical investigation of two-frequency forced Faraday waves
. [Thesis]. Kyoto University; 2015. Available from: http://hdl.handle.net/2433/199090
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
NSYSU
30.
Hsieh, Cheng-yen.
Thermocapillary convection effects on phase change at two-dimensional corner.
Degree: Master, Mechanical and Electro-Mechanical Engineering, 2013, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0729113-125410
► This thesis implicates the use of Phase-field method, to create a simulation of the transient thermal of the surface of a metallic material, molten or…
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▼ This thesis implicates the use of Phase-field
method, to create a simulation of the transient thermal of the surface of a metallic material, molten or solidified by the heat flux during process. The project itself is considered acquainted with mass conservation equation, momentum equation, energy equation and
level-
set equation. In order to reach the results within the flow field domain, temperature, pressure, streamline and
level-
set number. This research is about the changes of corner flow between fusion area and solid area, uses different boundary conditions to forecast the disparity of corner field change. Such as solidified, surface fill, whirlpool phenomenons or the formation of ripples. In add, the results will display the area where flows of the molten are forced by thermocapillary. Which is caused by surface tension and temperature gradient.
Advisors/Committee Members: Han-Taw Chen (chair), Fei-Bin Hsiao (chair), Peng-Sheng Wei (committee member), Long-Jeng Chen (chair).
Subjects/Keywords: Two-phase flow; Phase-field method; corner flow; Thermocapillary; Level-set equation
Record Details
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Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hsieh, C. (2013). Thermocapillary convection effects on phase change at two-dimensional corner. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0729113-125410
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Hsieh, Cheng-yen. “Thermocapillary convection effects on phase change at two-dimensional corner.” 2013. Thesis, NSYSU. Accessed March 05, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0729113-125410.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Hsieh, Cheng-yen. “Thermocapillary convection effects on phase change at two-dimensional corner.” 2013. Web. 05 Mar 2021.
Vancouver:
Hsieh C. Thermocapillary convection effects on phase change at two-dimensional corner. [Internet] [Thesis]. NSYSU; 2013. [cited 2021 Mar 05].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0729113-125410.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Hsieh C. Thermocapillary convection effects on phase change at two-dimensional corner. [Thesis]. NSYSU; 2013. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0729113-125410
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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Open Access Theses and Dissertations
