You searched for subject:(Finite Volume).
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Texas A&M University
1.
Ponnalagu, Alagappan.
Dynamic Response of Viscoelastic Solids Described by Implicit Constitutive Theories.
Degree: PhD, Mechanical Engineering, 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155588 
► The aim of this work is to study the impact response of multilayered polymers using a thermodynamically consistent framework. Rather than integral type viscoelastic model,…
(more)
▼ The aim of this work is to study the impact response of multilayered polymers using a thermodynamically consistent framework. Rather than integral type viscoelastic model, the approach here is based on the idea of two inter penetrating networks, one is permanent and other is transient together with the rate equations for the time evolution of the transient network. The primary hypothesis is that, it is possible to use a two network theory to capture the essential features of a impact response of multilayered polymers and solve the resulting boundary value problem using
finite volume scheme.
We first study the impact of layered polymer plate involving small deformation using a thermodynamic framework. The constitutive equations are nonlinear even though the strains are small. Six different protocols involving PU and PC, namely pure PC, pure PU, bilayer(PU/PC and PC/PU) and trilayer(PU/PC/PU and PC/PU/PC) were considered to evaluate the performance of the layering sequence based on the kinetic energy transferred on the wall. The interfaces are assumed to be fully bonded. The material parameters for the model was obtained from the experimental creep data from the literature. The layering of polymers improved the performance of plate depending upon the type of layering sequence. In the one and two dimensional study carried out, the performance was best when a compliant layer is placed between two stiff layers. Whereas, when a stiff layer was placed between two less compliant layer, the performance was worse than bilayer. Finally, a thermodynamically consistent
finite deformation model was used to evaluate the impact performance of layered plate involving large deformation. A full scale three dimensional impact analysis was carried out with the thermal phenomena suppressed. Similar to the small deformation study, six different protocols were considered. The material parameters were obtained from the experimental data from the literature involving strain values above 50%. The overall performance was similar to what has been observed in the small strain model.
Advisors/Committee Members: Rajagopal, Kumbakonam R (advisor), Srinivasa, Arun R (advisor), Walton, Jay R (committee member), Muliana, Anastasia H (committee member).
Subjects/Keywords: Implicit; Finite Volume method
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APA (6th Edition):
Ponnalagu, A. (2015). Dynamic Response of Viscoelastic Solids Described by Implicit Constitutive Theories. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155588
Chicago Manual of Style (16th Edition):
Ponnalagu, Alagappan. “Dynamic Response of Viscoelastic Solids Described by Implicit Constitutive Theories.” 2015. Doctoral Dissertation, Texas A&M University. Accessed January 17, 2021.
http://hdl.handle.net/1969.1/155588.
MLA Handbook (7th Edition):
Ponnalagu, Alagappan. “Dynamic Response of Viscoelastic Solids Described by Implicit Constitutive Theories.” 2015. Web. 17 Jan 2021.
Vancouver:
Ponnalagu A. Dynamic Response of Viscoelastic Solids Described by Implicit Constitutive Theories. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/1969.1/155588.
Council of Science Editors:
Ponnalagu A. Dynamic Response of Viscoelastic Solids Described by Implicit Constitutive Theories. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155588
Delft University of Technology
2.
Tselempis, Romanos (author).
Finite volume method for modelling of linear elastic deformation: Extension to three dimensions and comparison with finite element method.
Degree: 2020, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:7910e08c-83e0-47d6-ae1a-53d0722db461
► The demand for accurate and efficient simulations in order to test the geomechanical effects is a reality for the entire geoscience community. The motivation that…
(more)
▼ The demand for accurate and efficient simulations in order to test the geomechanical effects is a reality for the entire geoscience community. The motivation that arises from that need is the development and the evolution of modelling methods to study these effects. Deep understanding of any problem in fine scale is crucial, especially when it extends to much coarser scales. In this work the
finite volume method (FVM) is used for mechanical modelling of deformation in elastic media. The momentum balance equation is solved as the governing equation for mechanics, assuming linear elasticity for the stress tensor. Here, displacement is mapped onto a vertex-centred grid in three dimensions (3D). A set of eight trilinear basis functions are used to locally interpolate the value of displacement within each grid cube. In the
finite volume method, the discretized form of the equations are obtained by integrating the governing equation over control
volume surfaces, since in 3D the control
volume is a cube. Hence, discretized forms are obtained by considering 24 surfaces, which form between a displacement node and its neighbouring displacement cells. This required extensive derivation. The implementation of the numerical model was carried out by writing a code in MATLAB. Several numerical test cases are presented to demonstrate the capability of this model. In the first place, the consistency of the model is checked through comparison with synthetic analytical solutions, which are compared to the numerical solutions. Furthermore, the simple test case of uniaxial compression, has been carried out with this model, but also compared to the results with a 2D FVM model and a 3D
finite element (3D FEM) one. In another test case, ground plain strain subsidence is studied in a real hydrocarbon field with a heterogeneous map for elasticity parameters. It is shown that 3D FVM is in close agreement with 3D FEM in predicting the subsidence due to field depletion. Last but not least, displacement and stresses, in a faulted reservoir in which fluids are injected, are modelled and the results are shown to coincide with a robust analytical solutions for the system. Finally, the aim of this work is to shed some more light on the
finite volume method for mechanics and bring it closer to the audience of science.
Advisors/Committee Members: Hajibeygi, H. (mentor), Gerritsma, M.I. (graduation committee), Muntendam-Bos, A.G. (graduation committee), Ramesh Kumar, K. (graduation committee), Shokrollahzadeh Behbahani, S. (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: Finite Volume Methods; Finite element method; Mechanics
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APA (6th Edition):
Tselempis, R. (. (2020). Finite volume method for modelling of linear elastic deformation: Extension to three dimensions and comparison with finite element method. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:7910e08c-83e0-47d6-ae1a-53d0722db461
Chicago Manual of Style (16th Edition):
Tselempis, Romanos (author). “Finite volume method for modelling of linear elastic deformation: Extension to three dimensions and comparison with finite element method.” 2020. Masters Thesis, Delft University of Technology. Accessed January 17, 2021.
http://resolver.tudelft.nl/uuid:7910e08c-83e0-47d6-ae1a-53d0722db461.
MLA Handbook (7th Edition):
Tselempis, Romanos (author). “Finite volume method for modelling of linear elastic deformation: Extension to three dimensions and comparison with finite element method.” 2020. Web. 17 Jan 2021.
Vancouver:
Tselempis R(. Finite volume method for modelling of linear elastic deformation: Extension to three dimensions and comparison with finite element method. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Jan 17].
Available from: http://resolver.tudelft.nl/uuid:7910e08c-83e0-47d6-ae1a-53d0722db461.
Council of Science Editors:
Tselempis R(. Finite volume method for modelling of linear elastic deformation: Extension to three dimensions and comparison with finite element method. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:7910e08c-83e0-47d6-ae1a-53d0722db461
Anna University
3.
Sundararaj, K.
Numerical investigation on Staged transverse injection in
a Scramjet combustor and its mixing Augmentation using expansion
ramp; -.
Degree: Mechanical Engineering, 2014, Anna University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/27238
► This work involves an application of the computational fluid newlinedynamics to a problem associated with the flow inside the supersonic newlinecombustor region of a scramjet…
(more)
▼ This work involves an application of the
computational fluid newlinedynamics to a problem associated with
the flow inside the supersonic newlinecombustor region of a
scramjet engine An existing supersonic combustor newlinemodel
canonical model consisting of the staged transverse injection
behind a newlinerearward facing step was simulated for various flow
conditions to investigate newlinethe flow in detail A method for
augmenting the mixing of air and the fuel in newlinethe canonical
model was suggested by introducing the expansion ramps on
newlineboth the sides of the injectors and its effectiveness was
tested by numerical newlinemethods The intent was to promote
streamwise vorticity by modifying newlinegeometry to improve the
mixing characteristics in the combustor newlineThe combustor models
were simulated using the finite volume newlinebased code FLUENT and
the governing equations were solved by means of a newlinecoupled
explicit method using shear stress transport SST K turbulence
newlinemodel newline
reference p.154-159
Advisors/Committee Members: Dhandapani, S.
Subjects/Keywords: Finite volume based code; Shear stress transport
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APA (6th Edition):
Sundararaj, K. (2014). Numerical investigation on Staged transverse injection in
a Scramjet combustor and its mixing Augmentation using expansion
ramp; -. (Thesis). Anna University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/27238
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):
Sundararaj, K. “Numerical investigation on Staged transverse injection in
a Scramjet combustor and its mixing Augmentation using expansion
ramp; -.” 2014. Thesis, Anna University. Accessed January 17, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/27238.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sundararaj, K. “Numerical investigation on Staged transverse injection in
a Scramjet combustor and its mixing Augmentation using expansion
ramp; -.” 2014. Web. 17 Jan 2021.
Vancouver:
Sundararaj K. Numerical investigation on Staged transverse injection in
a Scramjet combustor and its mixing Augmentation using expansion
ramp; -. [Internet] [Thesis]. Anna University; 2014. [cited 2021 Jan 17].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/27238.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sundararaj K. Numerical investigation on Staged transverse injection in
a Scramjet combustor and its mixing Augmentation using expansion
ramp; -. [Thesis]. Anna University; 2014. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/27238
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
4.
Molenaar, S. (author).
Dynamic modeling of adipic acid crystallization.
Degree: 2011, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:270ea312-4b37-4c00-84f1-ac637cdfc9d0
A model was developed including nucleation, growth and agglomeration. The population balance was solved using a high order finite volume method.
IRS
Process and Energy
Mechanical, Maritime and Materials Engineering
Advisors/Committee Members: Kramer, H.J.M. (mentor), Mesbah, A. (mentor).Subjects/Keywords: crystallization; finite volume; pbe; adipicacid; modeling
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APA (6th Edition):
Molenaar, S. (. (2011). Dynamic modeling of adipic acid crystallization. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:270ea312-4b37-4c00-84f1-ac637cdfc9d0
Chicago Manual of Style (16th Edition):
Molenaar, S (author). “Dynamic modeling of adipic acid crystallization.” 2011. Masters Thesis, Delft University of Technology. Accessed January 17, 2021.
http://resolver.tudelft.nl/uuid:270ea312-4b37-4c00-84f1-ac637cdfc9d0.
MLA Handbook (7th Edition):
Molenaar, S (author). “Dynamic modeling of adipic acid crystallization.” 2011. Web. 17 Jan 2021.
Vancouver:
Molenaar S(. Dynamic modeling of adipic acid crystallization. [Internet] [Masters thesis]. Delft University of Technology; 2011. [cited 2021 Jan 17].
Available from: http://resolver.tudelft.nl/uuid:270ea312-4b37-4c00-84f1-ac637cdfc9d0.
Council of Science Editors:
Molenaar S(. Dynamic modeling of adipic acid crystallization. [Masters Thesis]. Delft University of Technology; 2011. Available from: http://resolver.tudelft.nl/uuid:270ea312-4b37-4c00-84f1-ac637cdfc9d0
Virginia Tech
5.
Wiersma, Codi Allen.
The Automation of Numerical Models of Coseismic Tsunamis.
Degree: MS, Geosciences, 2019, Virginia Tech
URL: http://hdl.handle.net/10919/93273
► Short term modeling of tsunamis generated by earthquakes is poorly explored. If an earthquake causes movement in a fault located underwater, and this movement will…
(more)
▼ Short term modeling of tsunamis generated by earthquakes is poorly explored. If an earthquake causes movement in a fault located underwater, and this movement will then cause the water column above it to be displaced. Tsunami models are sensitive to how the fault moves, and an accurate representation of this movement often takes much more time that the duration of a tsunami. This lengthy process is ineffective for short term modeling. This study instead estimates several possible scenarios of how the fault will behave, and model each of them. This will show how different locations of interest are sensitive to different geometries of fault failure. Initial results show that by varying this geometry, the tsunami wave behaves very differently, and will cause different amounts of run-up in the same location depending on which particular geometry is modeled. The automation of distinctly different earthquake sources serve as a good starting point for future work to be conducted to generate more accurate models.
Advisors/Committee Members: Weiss, Robert (committeechair), Warburton, Timothy (committee member), Stamps, D. Sarah (committee member), Chapman, Martin C. (committee member).
Subjects/Keywords: Numerical Modeling; Tsunami; GeoClaw; Finite Volume
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APA ·
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APA (6th Edition):
Wiersma, C. A. (2019). The Automation of Numerical Models of Coseismic Tsunamis. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/93273
Chicago Manual of Style (16th Edition):
Wiersma, Codi Allen. “The Automation of Numerical Models of Coseismic Tsunamis.” 2019. Masters Thesis, Virginia Tech. Accessed January 17, 2021.
http://hdl.handle.net/10919/93273.
MLA Handbook (7th Edition):
Wiersma, Codi Allen. “The Automation of Numerical Models of Coseismic Tsunamis.” 2019. Web. 17 Jan 2021.
Vancouver:
Wiersma CA. The Automation of Numerical Models of Coseismic Tsunamis. [Internet] [Masters thesis]. Virginia Tech; 2019. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/10919/93273.
Council of Science Editors:
Wiersma CA. The Automation of Numerical Models of Coseismic Tsunamis. [Masters Thesis]. Virginia Tech; 2019. Available from: http://hdl.handle.net/10919/93273
Wright State University
6.
Gross, Paul A., II.
Commercial Program Development for a Ground Loop Geothermal
System: Energy Loads, GUI, Turbulent Flow, Heat Pump Model and Grid
Study.
Degree: MSEgr, Renewable and Clean Energy, 2011, Wright State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=wright1324258915
► The use of the earth's thermal energy to heat and cool building space is nothing new; however, the heat transfer approximations used in modeling geothermal…
(more)
▼ The use of the earth's thermal energy to heat and cool
building space is nothing new; however, the heat transfer
approximations used in modeling geothermal systems, leave
uncertainty and lead to over sizing. The present work is part of a
Wright State effort to improve the computer modeling tools used to
simulate ground loop geothermal heating and cooling systems. The
modern computer processor has equipped us with the computation
speed to use a
finite volume technique to solve the unsteady heat
equation with hourly time steps for multi-year analyses in multiple
spatial dimensions. Thus we feel there is more need to use
approximate heat transfer solution techniques to model geothermal
heating and cooling systems.As part of a DOE funded project Wright
State has been developing a ground loop geothermal computer
modeling tool that uses a detailed heat transfer model based on the
governing differential energy equation. This tool is meant to be
more physically detailed and accurate than current commercial
ground loop geothermal computer codes. The Wright State code allows
the geothermal designer to optimize the system using a number of
outputs including temperature field outputs, existing fluid
temperature plots, heat exchange plots, and even a histogram of the
COP data. Careful attention to the algorithm speed allows for
multi-year simulations with minimal computation cost. Once the
thermal and heat transfer computations are complete, a payback
period calculator can compare any conventional heating and cooling
system to the designed geothermal system and payback periods are
displayed.The work being presented as part of this thesis deals
with five issues that were required to make the Wright State
geothermal computer code a reality. The five aspects of this
modeling tool addressed by this thesis work are: energy load
calculations, GUI (graphical user interface) development,
turbulence model development, heat pump model development, and
two-dimensional numerical grid development. The energy load, or
heating and cooling load, calculations are handled using the
sophisticated DOE program called EnergyPlus. This thesis work
developed a technique for coupling EnergyPlus to the Wright State
geothermal code and devising a way for novice users to obtain
energy loads quickly and easily, while still allowing expert users
to utilize the full strength of EnergyPlus. The GUI for the Wright
State computer program was developed with the novice and expert
users in mind. The GUI offers ease of use while maintaining the
ability for the expert users to setup unique designs for
simulation. A unique way of modeling the effects of turbulent flow
in the ground tube has allowed the Wright State code to maintain
low computation times, while having small errors for a wide range
of Reynolds numbers. To make the Wright State ground loop computer
model more complete, a heat pump was developed as part of this
work. The heat pump model uses the performance characteristics of
commercial heat pumps to determine the performance of the
geothermal system. The…
Advisors/Committee Members: Menart, James (Committee Chair).
Subjects/Keywords: Mechanical Engineering; geothermal; numerical; EnergyPlus; finite volume
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APA (6th Edition):
Gross, Paul A., I. (2011). Commercial Program Development for a Ground Loop Geothermal
System: Energy Loads, GUI, Turbulent Flow, Heat Pump Model and Grid
Study. (Masters Thesis). Wright State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=wright1324258915
Chicago Manual of Style (16th Edition):
Gross, Paul A., II. “Commercial Program Development for a Ground Loop Geothermal
System: Energy Loads, GUI, Turbulent Flow, Heat Pump Model and Grid
Study.” 2011. Masters Thesis, Wright State University. Accessed January 17, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=wright1324258915.
MLA Handbook (7th Edition):
Gross, Paul A., II. “Commercial Program Development for a Ground Loop Geothermal
System: Energy Loads, GUI, Turbulent Flow, Heat Pump Model and Grid
Study.” 2011. Web. 17 Jan 2021.
Vancouver:
Gross, Paul A. I. Commercial Program Development for a Ground Loop Geothermal
System: Energy Loads, GUI, Turbulent Flow, Heat Pump Model and Grid
Study. [Internet] [Masters thesis]. Wright State University; 2011. [cited 2021 Jan 17].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=wright1324258915.
Council of Science Editors:
Gross, Paul A. I. Commercial Program Development for a Ground Loop Geothermal
System: Energy Loads, GUI, Turbulent Flow, Heat Pump Model and Grid
Study. [Masters Thesis]. Wright State University; 2011. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=wright1324258915
Colorado State University
7.
Meisner, Noah.
Entropy stability for a fourth-order accurate finite-volume method for Burgers' equation.
Degree: MS(M.S.), Mechanical Engineering, 2019, Colorado State University
URL: http://hdl.handle.net/10217/195421
► Computational fluid dynamics (CFD) algorithms need efficiency, accuracy, and robustness to be useful to engineers. Faster computers improve the effective speed of a given method,…
(more)
▼ Computational fluid dynamics (CFD) algorithms need efficiency, accuracy, and robustness to be useful to engineers. Faster computers improve the effective speed of a given method, and larger memories allow higher grid resolution, improving accuracy. However, robustness cannot be achieved through advancements in computer hardware. Improvements in this area require a fundamental understanding of the mathematical and physical aspects of the algorithm being investigated. For high-order numerical algorithms, the stability can easily be aggravated with the presence of strong gradients. Many methods in CFD incorporate some kind of numerical limiter to suppress spurious oscillations and handle nonlinear instabilities for flows with strong discontinuities. However, these limiters often lack a basis in the physics that governs the fluid flow. For this reason, the present research employs a limiting method that is based on the second law of thermodynamics to achieve numerical robustness for a higher order code in solving flows with strong discontinuities. The aim of this work is to address the question of robustness for a high-order
finite-
volume method (FVM) by extending the entropy stability strategy developed by Marshal L. Merriam for a second-order FVM. Unlike generic limiters or artificial viscosity, the approach explored in this thesis provides a physical, quantitative explanation for artificial viscosity or limiters in the form of entropy. The mathematical derivation of the entropy stability method is presented in detail, shortcomings of the method by Merriam are explored, and a more robust approach to deriving an entropy stable limiting method was carried out for the low-order methods. As a first step, this study focuses on the application to Burgers' equation for both a first- and second-order accurate solution to a problem with the onset of shocks. Then, a cell entropy fix for the fourth-order discretization scheme is derived and applied to Burgers' equations. Although the oscillations near the discontinuities can be mitigated, the logical conditions associated with ensuring the entropy constraints become impractical to implement for high-order discretization schemes. Through this research, it is deemed that the entropy stability method proposed by Merriam may not be a viable solution to effectively suppress oscillations near strong discontinuities of problems governed by systems of nonlinear equations, particularly, for high-order schemes.
Advisors/Committee Members: Gao, Xinfeng (advisor), Guzik, Stephen (committee member), Liu, Jiannguo (committee member).
Subjects/Keywords: computational; finite-volume; algorithm; fluid; dynamics
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APA ·
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Manager
APA (6th Edition):
Meisner, N. (2019). Entropy stability for a fourth-order accurate finite-volume method for Burgers' equation. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/195421
Chicago Manual of Style (16th Edition):
Meisner, Noah. “Entropy stability for a fourth-order accurate finite-volume method for Burgers' equation.” 2019. Masters Thesis, Colorado State University. Accessed January 17, 2021.
http://hdl.handle.net/10217/195421.
MLA Handbook (7th Edition):
Meisner, Noah. “Entropy stability for a fourth-order accurate finite-volume method for Burgers' equation.” 2019. Web. 17 Jan 2021.
Vancouver:
Meisner N. Entropy stability for a fourth-order accurate finite-volume method for Burgers' equation. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/10217/195421.
Council of Science Editors:
Meisner N. Entropy stability for a fourth-order accurate finite-volume method for Burgers' equation. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195421
King Abdullah University of Science and Technology
8.
Mantravadi, Bhargav.
Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension.
Degree: 2019, King Abdullah University of Science and Technology
URL: http://hdl.handle.net/10754/644887
► The ideal two-fluid plasma model is a more generalized plasma model compared to the ideal MHD and it couples the ion and electron Euler equations…
(more)
▼ The ideal two-fluid plasma model is a more generalized plasma model compared to the ideal MHD and it couples the ion and electron Euler equations via Maxwell's equations. Two-fluid plasma model is essential when the ion and electron fluids are at different temperatures. In this work, a fundamental investigation on the effect of non-dimensional light speed, ion-to-electron mass ratio and plasma beta on the plasma dynamics in the Brio-Wu shock tube Riemann problem is presented. A one dimensional finite volume code is developed based on the macroscopic governing equations, with second order accuracy in space and time. The source terms are treated implicitly and the homogeneous flux terms are treated explicitly. The credibility of the numerical results is assessed by performing several linear and nonlinear tests.
Realistic light speed results in increasing the stiffness of the equations and severe time step restriction, which poses a challenge to the numerical simulations. In the context of the Brio-Wu shock tube problem, it is observed that the light speed is not important with respect to the hydrodynamics. However, light speed does affect the magnitude of the self generated electric field. Mass ratio affects the electron plasma dynamics. The speed of the fast moving electron plasma waves changes with the mass ratio. The results obtained using a mass ratio of 500 are in close agreement with that of realistic mass ratio of 1836. Increasing plasma beta suppresses the amplitude of the fast moving electron plasma waves.
Subjects/Keywords: two-fluid plasma; MHD; Finite Volume Method
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APA (6th Edition):
Mantravadi, B. (2019). Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/644887
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):
Mantravadi, Bhargav. “Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension.” 2019. Thesis, King Abdullah University of Science and Technology. Accessed January 17, 2021.
http://hdl.handle.net/10754/644887.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mantravadi, Bhargav. “Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension.” 2019. Web. 17 Jan 2021.
Vancouver:
Mantravadi B. Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2019. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/10754/644887.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mantravadi B. Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension. [Thesis]. King Abdullah University of Science and Technology; 2019. Available from: http://hdl.handle.net/10754/644887
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
9.
Sokolova, Irina (author).
MultiScale finite volume method for finite-volume based poromechanics simulations.
Degree: 2018, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:5a9b21a8-b6fb-4719-af1d-8e57f9ab0f09
► We propose a multiscale finite volume method (MSFV) for simulation of coupled flow-deformation in heterogeneous porous media under elastic deformation (i.e., poroelastic model). The fine-scale…
(more)
▼ We propose a multiscale finite volume method (MSFV) for simulation of coupled flow-deformation in heterogeneous porous media under elastic deformation (i.e., poroelastic model). The fine-scale fully resolved system of equations is obtained based on a conservative finite-volume method in which the displacement and pore pressure unknowns are located in a staggered configuration. The coupling is treated through a fully-coupled fully-implicit formulation. On this fully-coupled finite-volume system, coarse-scale grids for flow and deformation are imposed. Local basis functions for scalar pore pressure and vectorial displacement unknowns are then solved over their respective local domains at the beginning of the simulation, and reused for the rest of the time-dependent simulations. These local basis functions are then clustered to form the prolongation operator. As for the finite-volume nature of the proposed multiscale system, finite-volume restriction operators for poroelastic systems are utilised. Once the coarse-scale system is solved, its solution is prolonged back to the original fine-scale resolution, providing approximate fine-scale solution. The finite-volume multiscale formulation provides conservative stress andmass flux both at fine and coarse scale. Several numerical test cases are provided first to validate the fine-scale finite-volume discrete fully-implicit simulation, and then to investigate the accuracy of the proposed multiscale formulation. Our multiscale method allows for quantification of the elastic geomechanical behaviour with using only a fraction of the fine-scale grid cells, even for highly heterogeneous time-dependent models. As such, it casts a promising approach for field-scale quantification of the mechanical deformation and stress field due to injection and production in a subsurface formation. In order to extend the fine-scale finite volume (FV) framework for fractured media, we implement a discontinuity enriched FV method for mechanical deformation. We model fracture shear failure, based on static friction law. We demonstrate the results, obtained for a single fracture test case and show convergence of shear slip solution. The discontinuity enriched FV method is a basis for promising developments within a coupled flow-deformation framework for fractured reservoirs.
Petroleum Engineering
Advisors/Committee Members: Hajibeygi, Hadi (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: multiscale finite-volume method; poromechanics; geomechanics; porous media; finite volume method; algebraic multiscale solver
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APA (6th Edition):
Sokolova, I. (. (2018). MultiScale finite volume method for finite-volume based poromechanics simulations. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:5a9b21a8-b6fb-4719-af1d-8e57f9ab0f09
Chicago Manual of Style (16th Edition):
Sokolova, Irina (author). “MultiScale finite volume method for finite-volume based poromechanics simulations.” 2018. Masters Thesis, Delft University of Technology. Accessed January 17, 2021.
http://resolver.tudelft.nl/uuid:5a9b21a8-b6fb-4719-af1d-8e57f9ab0f09.
MLA Handbook (7th Edition):
Sokolova, Irina (author). “MultiScale finite volume method for finite-volume based poromechanics simulations.” 2018. Web. 17 Jan 2021.
Vancouver:
Sokolova I(. MultiScale finite volume method for finite-volume based poromechanics simulations. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 17].
Available from: http://resolver.tudelft.nl/uuid:5a9b21a8-b6fb-4719-af1d-8e57f9ab0f09.
Council of Science Editors:
Sokolova I(. MultiScale finite volume method for finite-volume based poromechanics simulations. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:5a9b21a8-b6fb-4719-af1d-8e57f9ab0f09
University of Pretoria
10.
[No author].
Development of parallel strongly coupled hybrid
fluid-structure interaction technology involving thin geometrically
non-linear structures
.
Degree: 2012, University of Pretoria
URL: http://upetd.up.ac.za/thesis/available/etd-05022012-001550/
► This work details the development of a computational tool that can accurately model strongly-coupled fluid-structure-interaction (FSI) problems, with a particular focus on thin-walled structures undergoing…
(more)
▼ This work details the development of a computational
tool that can accurately model strongly-coupled
fluid-structure-interaction (FSI) problems, with a particular focus
on thin-walled structures undergoing large, geometrically
non-linear deformations, which has a major interest in, amongst
others, the aerospace and biomedical industries. The first part of
this work investigates improving the efficiency with which a stable
and robust in-house code, Elemental, models thin structures
undergoing dynamic fluid-induced bending deformations. Variations
of the existing
finite volume formulation as well as linear and
higher-order
finite element formulations are implemented. The
governing equations for the solid domain are formulated in a total
Lagrangian or undeformed conguration and large geometrically
non-linear deformations are accounted for. The set of equations is
solved via a single-step Jacobi iterative scheme which is
implemented such as to ensure a matrix-free and robust solution.
Second-order accurate temporal discretisation is achieved via
dual-timestepping, with both consistent and lumped mass matrices
and with a Jacobi pseudo-time iteration method employed for
solution purposes. The matrix-free approach makes the scheme
particularly well-suited for distributed memory parallel hardware
architectures. Three key outcomes, not well documented in
literature, are highlighted: the issue of shear locking or
sensitivity to element aspect ratio, which is a common problem with
the linear Q4
finite element formulation when subjected to bending,
is evaluated on the
finite volume formulations; a rigorous
comparison of
finite element vs.
finite volume methods on
geometrically non-linear structures is done; a higher-order
finite
volume solid mechanics procedure is developed and evaluated. The
second part of this work is concerned with fluid-structure
interaction (FSI) modelling. It considers the implementation and
coupling of a higher order
finite element structural solver with
the existing
finite volume fluid-flow solver in Elemental. To the
author’s knowledge, this is the first instance in which a
strongly-coupled hybrid
finite element–
finite volume FSI
formulation is developed. The coupling between the fluid and
structural components with non-matching nodes is rigorously
assessed. A new partitioned fluid-solid interface coupling
methodology is also developed, which ensures stable partitioned
solution for strongly-coupled problems without any additional
computational overhead. The solver is parallelised for distributed
memory parallel hardware architectures. The developed technology is
successfully validated through rigorous temporal and mesh
independent studies of representative two-dimensional
strongly-coupled large-displacement FSI test problems for which
analytical or benchmark solutions exist.
Advisors/Committee Members: Prof A G Malan (advisor), Dr S Kok (advisor), Prof J P Meyer (advisor).
Subjects/Keywords: Fluid-structure interaction;
Finite volume;
Finite element;
UCTD
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
author], [. (2012). Development of parallel strongly coupled hybrid
fluid-structure interaction technology involving thin geometrically
non-linear structures
. (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-05022012-001550/
Chicago Manual of Style (16th Edition):
author], [No. “Development of parallel strongly coupled hybrid
fluid-structure interaction technology involving thin geometrically
non-linear structures
.” 2012. Masters Thesis, University of Pretoria. Accessed January 17, 2021.
http://upetd.up.ac.za/thesis/available/etd-05022012-001550/.
MLA Handbook (7th Edition):
author], [No. “Development of parallel strongly coupled hybrid
fluid-structure interaction technology involving thin geometrically
non-linear structures
.” 2012. Web. 17 Jan 2021.
Vancouver:
author] [. Development of parallel strongly coupled hybrid
fluid-structure interaction technology involving thin geometrically
non-linear structures
. [Internet] [Masters thesis]. University of Pretoria; 2012. [cited 2021 Jan 17].
Available from: http://upetd.up.ac.za/thesis/available/etd-05022012-001550/.
Council of Science Editors:
author] [. Development of parallel strongly coupled hybrid
fluid-structure interaction technology involving thin geometrically
non-linear structures
. [Masters Thesis]. University of Pretoria; 2012. Available from: http://upetd.up.ac.za/thesis/available/etd-05022012-001550/
University of Pretoria
11.
Suliman, Ridhwaan.
Development of
parallel strongly coupled hybrid fluid-structure interaction
technology involving thin geometrically non-linear
structures.
Degree: Mechanical and Aeronautical
Engineering, 2012, University of Pretoria
URL: http://hdl.handle.net/2263/24288
► This work details the development of a computational tool that can accurately model strongly-coupled fluid-structure-interaction (FSI) problems, with a particular focus on thin-walled structures undergoing…
(more)
▼ This work details the development of a computational tool
that can accurately model strongly-coupled
fluid-structure-interaction (FSI) problems, with a particular focus
on thin-walled structures undergoing large, geometrically
non-linear deformations, which has a major interest in, amongst
others, the aerospace and biomedical industries. The first part of
this work investigates improving the efficiency with which a stable
and robust in-house code, Elemental, models thin structures
undergoing dynamic fluid-induced bending deformations. Variations
of the existing
finite volume formulation as well as linear and
higher-order
finite element formulations are implemented. The
governing equations for the solid domain are formulated in a total
Lagrangian or undeformed conguration and large geometrically
non-linear deformations are accounted for. The set of equations is
solved via a single-step Jacobi iterative scheme which is
implemented such as to ensure a matrix-free and robust solution.
Second-order accurate temporal discretisation is achieved via
dual-timestepping, with both consistent and lumped mass matrices
and with a Jacobi pseudo-time iteration method employed for
solution purposes. The matrix-free approach makes the scheme
particularly well-suited for distributed memory parallel hardware
architectures. Three key outcomes, not well documented in
literature, are highlighted: the issue of shear locking or
sensitivity to element aspect ratio, which is a common problem with
the linear Q4
finite element formulation when subjected to bending,
is evaluated on the
finite volume formulations; a rigorous
comparison of
finite element vs.
finite volume methods on
geometrically non-linear structures is done; a higher-order
finite
volume solid mechanics procedure is developed and evaluated. The
second part of this work is concerned with fluid-structure
interaction (FSI) modelling. It considers the implementation and
coupling of a higher order
finite element structural solver with
the existing
finite volume fluid-flow solver in Elemental. To the
author’s knowledge, this is the first instance in which a
strongly-coupled hybrid
finite element–
finite volume FSI
formulation is developed. The coupling between the fluid and
structural components with non-matching nodes is rigorously
assessed. A new partitioned fluid-solid interface coupling
methodology is also developed, which ensures stable partitioned
solution for strongly-coupled problems without any additional
computational overhead. The solver is parallelised for distributed
memory parallel hardware architectures. The developed technology is
successfully validated through rigorous temporal and mesh
independent studies of representative two-dimensional
strongly-coupled large-displacement FSI test problems for which
analytical or benchmark solutions exist.
Advisors/Committee Members: Malan, A.G. (advisor), Kok, Schalk (advisor), Meyer, Josua P. (advisor).
Subjects/Keywords: Fluid-structure interaction (FSI); Finite
volume; Finite
element;
UCTD
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Suliman, R. (2012). Development of
parallel strongly coupled hybrid fluid-structure interaction
technology involving thin geometrically non-linear
structures. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/24288
Chicago Manual of Style (16th Edition):
Suliman, Ridhwaan. “Development of
parallel strongly coupled hybrid fluid-structure interaction
technology involving thin geometrically non-linear
structures.” 2012. Masters Thesis, University of Pretoria. Accessed January 17, 2021.
http://hdl.handle.net/2263/24288.
MLA Handbook (7th Edition):
Suliman, Ridhwaan. “Development of
parallel strongly coupled hybrid fluid-structure interaction
technology involving thin geometrically non-linear
structures.” 2012. Web. 17 Jan 2021.
Vancouver:
Suliman R. Development of
parallel strongly coupled hybrid fluid-structure interaction
technology involving thin geometrically non-linear
structures. [Internet] [Masters thesis]. University of Pretoria; 2012. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/2263/24288.
Council of Science Editors:
Suliman R. Development of
parallel strongly coupled hybrid fluid-structure interaction
technology involving thin geometrically non-linear
structures. [Masters Thesis]. University of Pretoria; 2012. Available from: http://hdl.handle.net/2263/24288
University of Windsor
12.
Salih, Ali.
A New Cell-Centred Finite Difference Scheme for CFD Simulations.
Degree: MA, Mechanical, Automotive, and Materials Engineering, 2011, University of Windsor
URL: https://scholar.uwindsor.ca/etd/5388
► The governing partial differential equations of fluid motion are usually numerically approximated using one of the three classical methods: Finite Difference (FD), Finite Volume…
(more)
▼ The governing partial differential equations of fluid motion are usually numerically approximated using one of the three classical methods:
Finite Difference (FD),
Finite Volume (FV) or
Finite Element (FE). In this thesis, a new cell-centred FD (CCFD) formulation is developed, in which the governing fluid flow equations are differenced over all the cell centres instead of grid points. The nodes (grid points) are then updated by averaging the property from all the cell centres that share that node. This feature, which is motivated by development of the FV method, allows the application of the proposed FD numerical formulation on unstructured grids. Several test cases are investigated here to illustrate this approach. To verify the results, the analytical solution for the test case is used if available. Otherwise, the numerical solution is compared to the traditional FD solution.
Advisors/Committee Members: Ronald M Barron.
Subjects/Keywords: Cell-Centred; Finite Difference; Finite Volume; Numerical Simulation; PDE
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Salih, A. (2011). A New Cell-Centred Finite Difference Scheme for CFD Simulations. (Masters Thesis). University of Windsor. Retrieved from https://scholar.uwindsor.ca/etd/5388
Chicago Manual of Style (16th Edition):
Salih, Ali. “A New Cell-Centred Finite Difference Scheme for CFD Simulations.” 2011. Masters Thesis, University of Windsor. Accessed January 17, 2021.
https://scholar.uwindsor.ca/etd/5388.
MLA Handbook (7th Edition):
Salih, Ali. “A New Cell-Centred Finite Difference Scheme for CFD Simulations.” 2011. Web. 17 Jan 2021.
Vancouver:
Salih A. A New Cell-Centred Finite Difference Scheme for CFD Simulations. [Internet] [Masters thesis]. University of Windsor; 2011. [cited 2021 Jan 17].
Available from: https://scholar.uwindsor.ca/etd/5388.
Council of Science Editors:
Salih A. A New Cell-Centred Finite Difference Scheme for CFD Simulations. [Masters Thesis]. University of Windsor; 2011. Available from: https://scholar.uwindsor.ca/etd/5388
University of Texas – Austin
13.
Trembacki, Bradley Louis.
Electrochemical transport simulation of 3D lithium-ion battery electrode microstructures.
Degree: PhD, Mechanical Engineering, 2015, University of Texas – Austin
URL: http://hdl.handle.net/2152/63883
► Lithium-ion batteries are commonly modeled using a volume-averaged formulation (porous electrode theory) in order to simulate battery behavior on a large scale. These methods utilize…
(more)
▼ Lithium-ion batteries are commonly modeled using a
volume-averaged formulation (porous electrode theory) in order to simulate battery behavior on a large scale. These methods utilize effective material properties and assume a simplified spherical geometry of the electrode particles. In contrast, a particle-scale (non-porous electrode) simulation applied to resolved electrode geometries predicts localized phenomena. Complete simulations of batteries require a coupling of the two scales to resolve the relevant physics. A central focus of this thesis is to develop a fully-coupled
finite volume methodology for the simulation of the electrochemical equations in a lithium-ion battery cell at both the particle scale and using
volume-averaged formulations. Due to highly complex electrode geometries at the particle scale, the formulation employs an unstructured computational mesh and is implemented within the MEMOSA software framework of Purdue’s PRISM (Prediction of Reliability, Integrity and Survivability of Microsystems) center. Stable and efficient algorithms are developed for full coupling of the nonlinear species transport equations, electrostatics, and Butler-Volmer kinetics. The model is applied to synthetic electrode particle beds for comparison with porous electrode theory simulations and to evaluate numerical performance capabilities. The model is also applied to a half-cell mesh created from a real cathode particle bed reconstruction to demonstrate the feasibility of such simulations. The second focus of the thesis is to investigate 3D battery electrode architectures that offer potential energy density and power density improvements over traditional particle bed battery geometries. A singular feature of these geometries is their interpenetrating nature, which significantly reduces diffusion distance. Advancement of micro-scale additive manufacturing techniques has made it possible to fabricate these electrode microarchitectures. A fully-coupled
finite volume methodology for the transport equations coupled to the relevant electrochemistry is implemented in the PETSc (Portable, Extensible Toolkit for Scientific Computation) software framework which allows for a straightforward scalable simulation on orthogonal hexahedral meshes. Such scalability becomes important when performing simulations on fully resolved microstructures with many parameter sweeps across multiple variables. Using the computational model, a variety of 3D battery electrode geometries are simulated and compared across various battery discharge rates and length scales in order to quantify performance trends and investigate geometrical factors that improve battery performance. The energy density and power density of the 3D battery microstructures are compared in several ways, including a uniform surface area to
volume ratio comparison as well as a comparison requiring a minimum manufacturable feature size. Significant performance improvements over traditional particle bed electrode designs are observed, and electrode microarchitectures…
Advisors/Committee Members: Murthy, Jayathi (advisor), Moser, Robert D (committee member), Roberts, Scott A (committee member), Duoss, Eric B (committee member), Chen, Dongmei (committee member).
Subjects/Keywords: Battery; Simulation; Lithium-ion; Microstructure; Transport; Finite volume; Interpenetrating; Particle-scale; Volume-averaged; PETSc
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Trembacki, B. L. (2015). Electrochemical transport simulation of 3D lithium-ion battery electrode microstructures. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/63883
Chicago Manual of Style (16th Edition):
Trembacki, Bradley Louis. “Electrochemical transport simulation of 3D lithium-ion battery electrode microstructures.” 2015. Doctoral Dissertation, University of Texas – Austin. Accessed January 17, 2021.
http://hdl.handle.net/2152/63883.
MLA Handbook (7th Edition):
Trembacki, Bradley Louis. “Electrochemical transport simulation of 3D lithium-ion battery electrode microstructures.” 2015. Web. 17 Jan 2021.
Vancouver:
Trembacki BL. Electrochemical transport simulation of 3D lithium-ion battery electrode microstructures. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2015. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/2152/63883.
Council of Science Editors:
Trembacki BL. Electrochemical transport simulation of 3D lithium-ion battery electrode microstructures. [Doctoral Dissertation]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/63883
Texas A&M University
14.
Frisani, Angelo 1980-.
Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach.
Degree: PhD, Nuclear Engineering, 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/148236
► Two immersed boundary methods (IBM) for the simulation of conjugate heat transfer problems with complex geometries are introduced: a finite element (IFEM) and a finite…
(more)
▼ Two immersed boundary methods (IBM) for the simulation of conjugate heat transfer problems with complex geometries are introduced: a
finite element (IFEM) and a
finite volume (IFVM) immersed boundary methods are discussed. In the IFEM a projection approach is presented for the coupled system of time-dependent incompressible Navier-Stokes equations (NSEs) and energy equation in conjunction with the immersed boundary method for solving fluid flow and heat transfer problems in the presence of rigid objects not represented by the underlying mesh. The IBM allows solving the flow for geometries with complex objects without the need of generating a body-fitted mesh. Dirichlet boundary constraints are satisfied applying a boundary force at the immersed body surface. Using projection and interpolation operators from the fluid
volume mesh to the solid surface mesh (i.e., the “immersed” boundary) and vice versa, it is possible to impose the extra constraint to the NSEs as a Lagrange multiplier in a fashion very similar to the effect pressure has on the momentum equations to satisfy the divergence-free constraint. The IFEM approach presented shows third order accuracy in space and second order accuracy in time when the simulation results for the Taylor-Green decaying vortex are compared to the analytical solution.
For the IFVM a ghost-cell approach with sharp interface scheme is used to enforce the boundary condition at the fluid/solid interface. The interpolation procedure at the immersed boundary preserves the overall second order accuracy of the base solver. The developed ghost-cell method is applied on a staggered configuration with the Semi-Implicit Method for Pressure-Linked Equations Revised algorithm. Second order accuracy in space and first order accuracy in time are obtained when the Taylor-Green decaying vortex test case is compared to the IFVM analytical solution.
Computations were performed using the IFEM and IFVM approaches for the two-dimensional flow over a backward-facing step, two-dimensional flow past a stationary circular cylinder, three-dimensional flow past a sphere and two and three-dimensional natural convection in an enclosure with/without immersed body. The numerical results obtained with the discussed IFEM and IFVM were compared against other IBMs available in literature and simulations performed with the commercial computational fluid dynamics code STAR-CCM+/V7.04.006. The benchmark test cases showed that the numerical results obtained with the implemented immersed boundary methods are in good agreement with the predictions from STAR-CCM+ and the numerical data from the other IBMs. The immersed boundary method based of
finite element approach is numerically more accurate than the IBM based on
finite volume discretization. In contrast, the latter is computationally more efficient than the former.
Advisors/Committee Members: Hassan, Yassin A (advisor), Annamalai, Kalyan (committee member), Chen, Hamn-Ching (committee member), Marlow, William H (committee member).
Subjects/Keywords: immersed boundary; sharp interface; diffuse interface; direct forcing; finite volume; finite element
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Frisani, A. 1. (2012). Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/148236
Chicago Manual of Style (16th Edition):
Frisani, Angelo 1980-. “Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach.” 2012. Doctoral Dissertation, Texas A&M University. Accessed January 17, 2021.
http://hdl.handle.net/1969.1/148236.
MLA Handbook (7th Edition):
Frisani, Angelo 1980-. “Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach.” 2012. Web. 17 Jan 2021.
Vancouver:
Frisani A1. Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/1969.1/148236.
Council of Science Editors:
Frisani A1. Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/148236
Penn State University
15.
Elsworth, Cooper W.
Verification of an Overset-grid Enabled Fluid-structure Interaction Solver.
Degree: 2014, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/22622
► Coupled systems occur when two domains governed by dissimilar physics interact dynamically, resulting in strong two-way coupling between the domains. Research into these systems has…
(more)
▼ Coupled systems occur when two domains governed by dissimilar physics interact dynamically, resulting in strong two-way coupling between the domains. Research into these systems has become increasingly prevalent due to the wide variety of physical examples that exhibit these characteristics, as well as recent advancements in computational capability and parallelism. A notable example of coupled systems occurs in fluid-structure interaction (FSI), in which a deformable solid is surrounded by and/or immersed in a fluid. These systems exhibit strong, two-way coupling between the fluid and solid domains that require the development of expanded computational methods to solve. While current methods have provided the basis for the solution of these types of problems, optimizations are needed to solve realistic FSI problems.
Existing overset mesh technology has been incorporated into an ALE based Fluid-Structure Interaction (FSI) code, producing a novel approach for investigating fully-coupled FSI phenomena. In particular, the Suggar++/DiRTlib overset mesh technology has been implemented into a partitioned FSI solver based on OpenFOAM and an in-house structural code. The impetus of this solver has been to address some of the problems that occur in complex FSI simulations, most notably concerns with the mesh motion experienced in large deformation cases. The overset solver intends to simplify mesh generation, maintain mesh quality throughout the simulation, and provide similar performance to current approaches. This thesis provides verification of the overset FSI solver and presents the effects of overset methods on FSI simulations.
Verification is presented through the method of manufactured solutions on the disparate solver components and mesh refinement studies are performed on the coupled code. The method of manufactured solutions provides rigorous code verification, with error magnitudes and solver convergence rates determined for the separate solver components. Discussion of the challenges experienced in the establishment of a unified manufactured solution for partitioned FSI algorithms is also presented. The disparate solvers used in this work are found to exhibit the expected orders of convergence, verifying the correct implementation of the governing equations in these domains. A mesh refinement study with Richardson extrapolation further confirms the monotonic convergence of the FSI solution, and provides insight into the order of accuracy of the coupled solver.
Use of the Turek and Hron benchmark case facilitates a consistent comparison of the proposed solver to current FSI methods and performance. Simulation data is presented, while investigations into the benefits of overset methods for FSI simulations is discussed. In addition, the relative performance of the solver is presented, in order to address the viability of the proposed solver's application.
Advisors/Committee Members: Jonathan S Pitt, Thesis Advisor/Co-Advisor, Scott Miller, Thesis Advisor/Co-Advisor.
Subjects/Keywords: Fluid-Structure Interaction; Verification; Method of Manufactured Solutions; Overset; Finite Volume; Finite Element
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Elsworth, C. W. (2014). Verification of an Overset-grid Enabled Fluid-structure Interaction Solver. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/22622
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):
Elsworth, Cooper W. “Verification of an Overset-grid Enabled Fluid-structure Interaction Solver.” 2014. Thesis, Penn State University. Accessed January 17, 2021.
https://submit-etda.libraries.psu.edu/catalog/22622.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Elsworth, Cooper W. “Verification of an Overset-grid Enabled Fluid-structure Interaction Solver.” 2014. Web. 17 Jan 2021.
Vancouver:
Elsworth CW. Verification of an Overset-grid Enabled Fluid-structure Interaction Solver. [Internet] [Thesis]. Penn State University; 2014. [cited 2021 Jan 17].
Available from: https://submit-etda.libraries.psu.edu/catalog/22622.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Elsworth CW. Verification of an Overset-grid Enabled Fluid-structure Interaction Solver. [Thesis]. Penn State University; 2014. Available from: https://submit-etda.libraries.psu.edu/catalog/22622
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Waterloo
16.
Rahman, G M Ashikur.
Numerical Simulation of Nonlinear and Dispersive Wave Equations using Adaptive Mesh Refinement (AMR).
Degree: 2020, University of Waterloo
URL: http://hdl.handle.net/10012/16015
► Numerical solution of time dependent Partial Differential Equations plays an important role in different fluid flow modelling problems. Sometimes a little portion of the computational…
(more)
▼ Numerical solution of time dependent Partial Differential Equations plays an important role in different fluid flow modelling problems. Sometimes a little portion of the computational domain needs high grid resolution in order to resolve phenomena such as steep fronts or shocks while use of a very high resolution mesh for the whole computational domain is a waste of computational resources since they are not required all over the domain. An Adaptive Mesh Refinement (AMR) procedure is an efficient and practical method for the numerical solution of Partial Differential Equation problems with regions of large gradients occupying a small subregion of the domain. An AMR algorithm refines grids by placing finer and finer subgrids in the different portions of the computational domain where they are required. For the time dependent problem the refinement is dynamic since the regions requiring refinement change with time and the AMR algorithm adaptively changes that. In this thesis we developed an AMR code for the numerical solution of linear, nonlinear and dispersive wave equations inspired by existing algorithms in the literature. In this work we kept the implementation simple and we use simple refinement criteria although the code allows for the use of more complex refinement criteria. In addition the implementation of the data structure was also kept simple. We have done the refinement in both time and space. In our code we generate finer grids which can also have finer grids using a recursive grid generation procedure. We give a review of some existing work along with the necessary components of our work. Numerical simulations of the linear advection equation, Burger's equation and the Regularized Long Wave (RLW) equation have been run with our AMR code. The results of these simulations are shown to have good agreement with numerical solutions obtained on fine resolution single grids which signify the success of our code. A significant time reduction in all the numerical simulations suggests the good performance of our code.
Subjects/Keywords: partial differential equation; finite volume method; finite difference method; adaptive mesh refinement
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APA (6th Edition):
Rahman, G. M. A. (2020). Numerical Simulation of Nonlinear and Dispersive Wave Equations using Adaptive Mesh Refinement (AMR). (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/16015
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):
Rahman, G M Ashikur. “Numerical Simulation of Nonlinear and Dispersive Wave Equations using Adaptive Mesh Refinement (AMR).” 2020. Thesis, University of Waterloo. Accessed January 17, 2021.
http://hdl.handle.net/10012/16015.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Rahman, G M Ashikur. “Numerical Simulation of Nonlinear and Dispersive Wave Equations using Adaptive Mesh Refinement (AMR).” 2020. Web. 17 Jan 2021.
Vancouver:
Rahman GMA. Numerical Simulation of Nonlinear and Dispersive Wave Equations using Adaptive Mesh Refinement (AMR). [Internet] [Thesis]. University of Waterloo; 2020. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/10012/16015.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Rahman GMA. Numerical Simulation of Nonlinear and Dispersive Wave Equations using Adaptive Mesh Refinement (AMR). [Thesis]. University of Waterloo; 2020. Available from: http://hdl.handle.net/10012/16015
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Edinburgh
17.
Hamilton, Brian.
Finite difference and finite volume methods for wave-based modelling of room acoustics.
Degree: PhD, 2016, University of Edinburgh
URL: http://hdl.handle.net/1842/22940
► Wave-based models of sound propagation can be used to predict and synthesize sounds as they would be heard naturally in room acoustic environments. The numerical…
(more)
▼ Wave-based models of sound propagation can be used to predict and synthesize sounds as they would be heard naturally in room acoustic environments. The numerical simulation of such models with traditional time-stepping grid-based methods can be an expensive process, due to the sheer size of listening environments (e.g., auditoriums and concert halls) and due to the temporal resolution required by audio rates that resolve frequencies up to the limit of human hearing. Finite difference methods comprise a simple starting point for such simulations, but they are known to suffer from approximation errors that may necessitate expensive grid refinements in order to achieve sufficient levels of accuracy. As such, a significant amount of research has gone into designing finite difference methods that are highly accurate while remaining computationally efficient. The problem of designing and using accurate finite difference schemes is compounded by the fact that room acoustics models require complex boundary conditions to model frequency-dependent wall impedances over non-trivial geometries. The implementation of such boundary conditions in a numerically stable manner has been a challenge for some time. Stable boundary conditions for finite difference room acoustics simulations have been formulated in the past, but generally they have only been useful in modelling trivial geometries (e.g., idealised shoebox halls). Finite volume methods have recently been shown to be a viable solution to the problem of complex boundary conditions over non-trivial geometries, and they also allow for the use of energy methods for numerical stability analyses. Finite volume methods lend themselves naturally to fully unstructured grids and they can simplify to the types of grids typically used in finite difference methods. This allows for room acoustics simulation models that balance the simplicity of finite difference methods for wave propagation in air with the detail of finite volume methods for the modelling of complex boundaries. This thesis is an exploration of these two distinct, yet related, approaches to wave-based room acoustic simulations. The overarching theme in this investigation is the balance between accuracy, computational efficiency, and numerical stability. Higher-order and optimised schemes in two and three spatial dimensions are derived and compared, towards the goal of finding accurate and efficient finite difference schemes. Numerical stability is analysed using frequency-domain analyses, as well as energy techniques whenever possible, allowing for stable and frequency-dependent boundary conditions appropriate for room acoustics modelling. Along the way, the use of non-Cartesian grids is investigated, geometric relationships between certain finite difference and finite volume schemes are explored, and some problems associated to staircasing effects at boundaries are considered. Also, models of sound absorption in air are incorporated into these numerical schemes, using physical parameters that are appropriate for room…
Subjects/Keywords: 620.2; room acoustics; finite difference methods; finite volume methods; FDTD methods; computational acoustics; numerical methods
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APA (6th Edition):
Hamilton, B. (2016). Finite difference and finite volume methods for wave-based modelling of room acoustics. (Doctoral Dissertation). University of Edinburgh. Retrieved from http://hdl.handle.net/1842/22940
Chicago Manual of Style (16th Edition):
Hamilton, Brian. “Finite difference and finite volume methods for wave-based modelling of room acoustics.” 2016. Doctoral Dissertation, University of Edinburgh. Accessed January 17, 2021.
http://hdl.handle.net/1842/22940.
MLA Handbook (7th Edition):
Hamilton, Brian. “Finite difference and finite volume methods for wave-based modelling of room acoustics.” 2016. Web. 17 Jan 2021.
Vancouver:
Hamilton B. Finite difference and finite volume methods for wave-based modelling of room acoustics. [Internet] [Doctoral dissertation]. University of Edinburgh; 2016. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/1842/22940.
Council of Science Editors:
Hamilton B. Finite difference and finite volume methods for wave-based modelling of room acoustics. [Doctoral Dissertation]. University of Edinburgh; 2016. Available from: http://hdl.handle.net/1842/22940
Virginia Tech
18.
Bloxom, Andrew Lawrence.
Numerical Simulation of the Fluid-Structure Interaction of a Surface Effect Ship Bow Seal.
Degree: PhD, Aerospace Engineering, 2014, Virginia Tech
URL: http://hdl.handle.net/10919/50592
► Numerical simulations of fluid-structure interaction (FSI) problems were performed in an effort to verify and validate a commercially available FSI tool. This tool uses an…
(more)
▼ Numerical simulations of fluid-structure interaction (FSI) problems were performed in an effort to verify and validate a commercially available FSI tool. This tool uses an iterative partitioned coupling scheme between CD-adapco's STAR-CCM+
finite volume fluid solver and Simulia's Abaqus
finite element structural solver to simulate the FSI response of a system. Preliminary verification and validation work (VandV) was carried out to understand the numerical behavior of the codes individually and together as a FSI tool.
Verification and Validation work that was completed included code order verification of the respective fluid and structural solvers with Couette-Pouiselle flow and Euler-Bernoulli beam theory. These results confirmed the 2nd order accuracy of the spatial discretizations used. Following that, a mixture of solution verifications and model calibrations was performed with the inclusion of the physics models implemented in the solution of the FSI problems. Solution verifications were completed for fluid and structural stand-alone models as well as for the coupled FSI solutions. These results re-confirmed the spatial order of accuracy but for more complex flows and physics models as well as the order of accuracy of the temporal discretizations. In lieu of a good material definition, model calibration is performed to reproduce the experimental results. This work used model calibration for both instances of hyperelastic materials which were presented in the literature as validation cases because these materials were defined as linear elastic.
Calibrated, three dimensional models of the bow seal on the University of Michigan bow seal test platform showed the ability to reproduce the experimental results qualitatively through averaging of the forces and seal displacements. These simulations represent the only current 3D results for this case. One significant result of this study is the ability to visualize the flow around the seal and to directly measure the seal resistances at varying cushion pressures, seal immersions, forward speeds, and different seal materials. SES design analysis could greatly benefit from the inclusion of flexible seals in simulations, and this work is a positive step in that direction. In future work, the inclusion of more complex seal geometries and contact will further enhance the capability of this tool.
Advisors/Committee Members: Neu, Wayne L. (committeechair), McCue-Weil, Leigh S. (committee member), Yim, Solomon C. (committee member), Roy, Christopher John (committee member).
Subjects/Keywords: Surface Effect Ship; Bow Seal; Finite Volume; Finite Element; Fluid-Structure Interaction; Iterative Partitioned Coupling
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APA (6th Edition):
Bloxom, A. L. (2014). Numerical Simulation of the Fluid-Structure Interaction of a Surface Effect Ship Bow Seal. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/50592
Chicago Manual of Style (16th Edition):
Bloxom, Andrew Lawrence. “Numerical Simulation of the Fluid-Structure Interaction of a Surface Effect Ship Bow Seal.” 2014. Doctoral Dissertation, Virginia Tech. Accessed January 17, 2021.
http://hdl.handle.net/10919/50592.
MLA Handbook (7th Edition):
Bloxom, Andrew Lawrence. “Numerical Simulation of the Fluid-Structure Interaction of a Surface Effect Ship Bow Seal.” 2014. Web. 17 Jan 2021.
Vancouver:
Bloxom AL. Numerical Simulation of the Fluid-Structure Interaction of a Surface Effect Ship Bow Seal. [Internet] [Doctoral dissertation]. Virginia Tech; 2014. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/10919/50592.
Council of Science Editors:
Bloxom AL. Numerical Simulation of the Fluid-Structure Interaction of a Surface Effect Ship Bow Seal. [Doctoral Dissertation]. Virginia Tech; 2014. Available from: http://hdl.handle.net/10919/50592
University of Texas – Austin
19.
Bryant, Eric Cushman.
Hydraulic fracture modeling with finite volumes and areas.
Degree: MSin Engineering, Petroleum Engineering, 2016, University of Texas – Austin
URL: http://hdl.handle.net/2152/47078
► In Chapter 1, a finite volume-based arbitrary fracture propagation model is used to simulate fracture growth and geomechanical stresses during hydraulic fracture treatments. Single-phase flow,…
(more)
▼ In Chapter 1, a
finite volume-based arbitrary fracture propagation model is used to simulate fracture growth and geomechanical stresses during hydraulic fracture treatments. Single-phase flow, poroelastic displacement, and in situ stress tensor equations are coupled within a poroelastic reservoir domain. Stress analysis is used to identify failure initiation that proceeds by failure along
Finite Volume (FV) cell faces in excess of a threshold effective stress. Fracture propagation proceeds by the cohesive zone (CZ) model, to simulate propagation of non-planar fractures in heterogeneous porous media under anisotropic far-field stress. In Chapter 2, we are concerned with stress analysis of both elastic and poroelastic solids on the same domain, using a FV-based numerical discretization. As such our main purposes are twofold: introduce a hydromechanical coupling term into the linear elastic displacement field equation, using the standard model of linearized poroelasticity; and, maintain the continuity of total traction over any multi-material interfaces (meaning an interface over which residual stresses, Biot’s coefficient, Young’s modulus, or Poisson’s ratio vary). In Chapter 3, we are concerned with modeling fluid flow in cracks bounded by deforming rock, and specifically, inside those initial discontinuities, softening regions and failed zones which constitute the solid interfaces of propagating hydraulic fractures. To accomplish this task the
Finite Area (FA) method is an ideal candidate, given its proven facility for the discretization and solution of 2D coupled partial differential equations along the boundaries of 3D domains. In Chapter 4, rock formations’ response to a propagating, pressurized hydraulic fracture is examined. In order to initiate CZ applied traction-separation processes, an effective stress tensor is constructed by additively combining the total stress with pore pressures multiplied into a scalar factor. In effect, this scalar factor constitutes the Biot’s coefficient as acts inside the CZ. Integral analysis at the cohesive tip is used to show that this factor must be equal to the Biot’s coefficient in the bounding solid (for a small-strain constitutive relation). Also, effects of an initial residual stress state are accounted for.
Advisors/Committee Members: Sharma, Mukul M. (advisor), Foster, John T (committee member).
Subjects/Keywords: Hydraulic fracture; Finite Volume; Finite Area; Hydraulic fracture modeling; Poroelastic solids; Poroelasticity; Cohesive zone
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APA (6th Edition):
Bryant, E. C. (2016). Hydraulic fracture modeling with finite volumes and areas. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/47078
Chicago Manual of Style (16th Edition):
Bryant, Eric Cushman. “Hydraulic fracture modeling with finite volumes and areas.” 2016. Masters Thesis, University of Texas – Austin. Accessed January 17, 2021.
http://hdl.handle.net/2152/47078.
MLA Handbook (7th Edition):
Bryant, Eric Cushman. “Hydraulic fracture modeling with finite volumes and areas.” 2016. Web. 17 Jan 2021.
Vancouver:
Bryant EC. Hydraulic fracture modeling with finite volumes and areas. [Internet] [Masters thesis]. University of Texas – Austin; 2016. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/2152/47078.
Council of Science Editors:
Bryant EC. Hydraulic fracture modeling with finite volumes and areas. [Masters Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/47078
Queensland University of Technology
20.
Pasdunkorale Arachchige, Jayantha.
Accurate finite volume methods for the numerical simulation of transport in highly anistropic media.
Degree: 2003, Queensland University of Technology
URL: http://eprints.qut.edu.au/37145/
Subjects/Keywords: Finite volume method; thesis; doctoral
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APA (6th Edition):
Pasdunkorale Arachchige, J. (2003). Accurate finite volume methods for the numerical simulation of transport in highly anistropic media. (Thesis). Queensland University of Technology. Retrieved from http://eprints.qut.edu.au/37145/
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):
Pasdunkorale Arachchige, Jayantha. “Accurate finite volume methods for the numerical simulation of transport in highly anistropic media.” 2003. Thesis, Queensland University of Technology. Accessed January 17, 2021.
http://eprints.qut.edu.au/37145/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pasdunkorale Arachchige, Jayantha. “Accurate finite volume methods for the numerical simulation of transport in highly anistropic media.” 2003. Web. 17 Jan 2021.
Vancouver:
Pasdunkorale Arachchige J. Accurate finite volume methods for the numerical simulation of transport in highly anistropic media. [Internet] [Thesis]. Queensland University of Technology; 2003. [cited 2021 Jan 17].
Available from: http://eprints.qut.edu.au/37145/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pasdunkorale Arachchige J. Accurate finite volume methods for the numerical simulation of transport in highly anistropic media. [Thesis]. Queensland University of Technology; 2003. Available from: http://eprints.qut.edu.au/37145/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Utah
21.
Nelson, Blake William.
Accurate and interactive visualization of high-order finite element fields.
Degree: PhD, Computing (School of), 2012, University of Utah
URL: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/1120/rec/128
► High-order finite element methods, using either the continuous or discontinuous Galerkin formulation, are becoming more popular in fields such as fluid mechanics,solid mechanics and computational…
(more)
▼ High-order finite element methods, using either the continuous or discontinuous Galerkin formulation, are becoming more popular in fields such as fluid mechanics,solid mechanics and computational electromagnetics. While the use of these methods is becoming increasingly common, there has not been a corresponding increase in the availability and use of visualization methods and software that are capable of displaying visualizations of these volumes both accurately and interactively. A fundamental problem with the majority of existing visualization techniques is that they do not understandnor respect the structure of a high-order field, leading to visualization error.Visualizations of high-order fields are generally created by first approximating the field with low-order primitives and then generating the visualization using traditionalmethods based on linear interpolation. The approximation step introduces error into the visualization pipeline, which requires the user to balance the competing goals of image quality, interactivity and resource consumption. In practice, visualizationsperformed this way are often either undersampled, leading to visualization error, or oversampled, leading to unnecessary computational effort and resource consumption.Without an understanding of the sources of error, the simulation scientist is unable to determine if artifacts in the image are due to visualization error, insufficient mesh resolution, or a failure in the underlying simulation. This uncertainty makes it difficultfor the scientists to make judgments based on the visualization, as judgments made on the assumption that artifacts are a result of visualization error when they are actually a more fundamental problem can lead to poor decision-making.This dissertation presents new visualization algorithms that use the high-order data in its native state, using the knowledge of the structure and mathematicalproperties of these fields to create accurate images interactively, while avoiding the error introduced by representing the fields with low-order approximations. First, a new algorithm for cut-surfaces is presented, specifically the accurate depiction of colormapsand contour lines on arbitrarily complex cut-surfaces. Second, a mathematical analysis of the evaluation of the volume rendering integral through a high-orderfield is presented, as well as an algorithm that uses this analysis to create accurate volume renderings. Finally, a new software system, the Element Visualizer (ElVis),is presented, which combines the ideas and algorithms created in this dissertation in a single software package that can be used by simulation scientists to create accurate visualizations. This system was developed and tested with the assistance of the ProjectX simulation team. The utility of our algorithms and visualization system are then demonstrated with examples from several high-order fluid flow simulations.
Subjects/Keywords: Cut surfaces; GPU programming; High-order finite elements; Visualization; Volume rendering
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APA (6th Edition):
Nelson, B. W. (2012). Accurate and interactive visualization of high-order finite element fields. (Doctoral Dissertation). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/1120/rec/128
Chicago Manual of Style (16th Edition):
Nelson, Blake William. “Accurate and interactive visualization of high-order finite element fields.” 2012. Doctoral Dissertation, University of Utah. Accessed January 17, 2021.
http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/1120/rec/128.
MLA Handbook (7th Edition):
Nelson, Blake William. “Accurate and interactive visualization of high-order finite element fields.” 2012. Web. 17 Jan 2021.
Vancouver:
Nelson BW. Accurate and interactive visualization of high-order finite element fields. [Internet] [Doctoral dissertation]. University of Utah; 2012. [cited 2021 Jan 17].
Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/1120/rec/128.
Council of Science Editors:
Nelson BW. Accurate and interactive visualization of high-order finite element fields. [Doctoral Dissertation]. University of Utah; 2012. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd3/id/1120/rec/128
University of Manchester
22.
Cozzi, Olivier.
Free surface flow simulation: correcting and benchmarking
the ALE method in Code_Saturne.
Degree: 2011, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:122180
► The present thesis was written by Olivier Cozzi at the University of Manchester in pursuance of the degree of Master of Philosophy in 2010. It…
(more)
▼ The present thesis was written by Olivier Cozzi at
the University of Manchester in pursuance of the degree of Master
of Philosophy in 2010. It presents “Free surface flow simulation:
correcting and benchmarking the ALE method in Code_Saturne”, that
is to say the implementation of free surface flows within
Code_Saturne, an in-house code developed by EDF (Électricité de
France) to solve CFD problems, using the Arbitrary Lagrangian
Eulerian (ALE) method already embedded in this code. For a code
like Code_Saturne, which aims at being easily implemented in a wide
range of applications, the handling of free surface flows is
critical because it extends the range of possible applications
(tank filling, marine turbine interactions with waves and currents,
water supply and reject points ...). Up to now, the ALE module
within Code_Saturne was only used for fluid coupling with a solid
structure; thus we had to adapt it to free-surface flows by adding
a convergence loop to perform the free surface movement
incrementally within each time step. Afterwards, the geometry was
updated at the outer iterations level by imposing the displacement
of each cell-vertex within the global domain: the cell-vertex
motion is then computed for the free-surface cell-vertices in the
first place and for the internal cell-vertices secondly. The new
free-surface module was then implemented to three different test
cases: a standing wave in a tank (unsteady test case with a
periodic analytic solution), a solitary wave in a tank (unsteady
test case with an analytic solution), a submerged hydrofoil (steady
test case with experimental measurements). The results are
encouraging and the feasibility is clearly demonstrated. Some
limitations still exist – mainly caused by the inaccurate
interpolation performed by Code_Saturne between the free-surface
cell-vertex displacement and the free-surface cell-face centre
velocities – but these could be eliminated during the next stages
of the project.
Advisors/Committee Members: Stansby, Peter.
Subjects/Keywords: finite volume method; ALE method; free surface flows; Code_Saturne
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Export
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APA (6th Edition):
Cozzi, O. (2011). Free surface flow simulation: correcting and benchmarking
the ALE method in Code_Saturne. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:122180
Chicago Manual of Style (16th Edition):
Cozzi, Olivier. “Free surface flow simulation: correcting and benchmarking
the ALE method in Code_Saturne.” 2011. Doctoral Dissertation, University of Manchester. Accessed January 17, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:122180.
MLA Handbook (7th Edition):
Cozzi, Olivier. “Free surface flow simulation: correcting and benchmarking
the ALE method in Code_Saturne.” 2011. Web. 17 Jan 2021.
Vancouver:
Cozzi O. Free surface flow simulation: correcting and benchmarking
the ALE method in Code_Saturne. [Internet] [Doctoral dissertation]. University of Manchester; 2011. [cited 2021 Jan 17].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:122180.
Council of Science Editors:
Cozzi O. Free surface flow simulation: correcting and benchmarking
the ALE method in Code_Saturne. [Doctoral Dissertation]. University of Manchester; 2011. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:122180
University of Saskatchewan
23.
Hosseini Kalajahi, Seyed Mehrdad 1987-.
ADDRESSING PARTIAL VOLUME ARTIFACTS WITH QUANTITATIVE COMPUTED TOMOGRAPHY-BASED FINITE ELEMENT MODELING OF THE HUMAN PROXIMAL TIBIA.
Degree: 2018, University of Saskatchewan
URL: http://hdl.handle.net/10388/8584
► Quantitative computed tomography (QCT) based finite element modeling (FE) has potential to clarify the role of subchondral bone stiffness in osteoarthritis. The limited spatial resolution…
(more)
▼ Quantitative computed tomography (QCT) based
finite element modeling (FE) has potential to clarify the role of subchondral bone stiffness in osteoarthritis. The limited spatial resolution of clinical CT systems, however, results in partial
volume (PV) artifacts and low contrast between the cortical and trabecular bone, which adversely affect the accuracy of QCT-FE models. Using different cortical modeling and partial
volume correction algorithms, the overall aim of this research was to improve the accuracy of QCT-FE predictions of stiffness at the proximal tibial subchondral surface.
For Study1, QCT-FE models of the human proximal tibia were developed by (1) separate modeling of cortical and trabecular bone (SM), and (2) continuum models (CM). QCT-FE models with SM and CM explained 76%-81% of the experimental stiffness variance with error ranging between 11.2% and 20.2%. SM did not offer any improvement relative to CM. The segmented cortical region indicated densities below the range reported for cortical bone, suggesting that cortical voxels were corrupted by PV artifacts. For Study #2, we corrected PV layers at the cortical bone using four different methods including: (1) Image Deblurring of all of the proximal tibia (IDA); (2) Image Deblurring of the cortical region (IDC); (3) Image Remapping (IR); and (4) Voxel Exclusion (VE). IDA resulted in low predictive accuracy with R2=50% and error of 76.4%. IDC explained 70% of the measured stiffness variance with 23.3% error. The IR approach resulted in an R2 of 81% with 10.6% error. VE resulted in the highest predictive accuracy with R2=84%, and 9.8% error. For Study #3, we investigated whether PV effects could be addressed by mapping bone’s elastic modulus (E) to mesh Gaussian points. Corresponding FE models using the Gauss-point method converged with larger elements when compared to the conventional method which assigned a single elastic modulus to each element (constant-E). The error at the converged mesh was similar for constant-E and Gauss-point; though, the Gauss-point method indicated this error with larger elements and less computation time (30 min vs 180 min).
This research indicated that separate modeling of cortical and trabecular bone did not improve predictions of stiffness at the subchondral surface. However, this research did indicate that PV correction has potential to improve QCT-FE models of subchondral bone. These models may help to clarify the role of subchondral bone stiffness in knee OA pathogenesis with living people.
Advisors/Committee Members: Johnston, James J.D., McWalter, Emily J., Lanovaz, Joel, Boulfiza, Mohammed.
Subjects/Keywords: QCT imaging; Finite Element modeling; Proximal tibia; Stiffness; Partial volume artifacts
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Export
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APA (6th Edition):
Hosseini Kalajahi, S. M. 1. (2018). ADDRESSING PARTIAL VOLUME ARTIFACTS WITH QUANTITATIVE COMPUTED TOMOGRAPHY-BASED FINITE ELEMENT MODELING OF THE HUMAN PROXIMAL TIBIA. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/8584
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):
Hosseini Kalajahi, Seyed Mehrdad 1987-. “ADDRESSING PARTIAL VOLUME ARTIFACTS WITH QUANTITATIVE COMPUTED TOMOGRAPHY-BASED FINITE ELEMENT MODELING OF THE HUMAN PROXIMAL TIBIA.” 2018. Thesis, University of Saskatchewan. Accessed January 17, 2021.
http://hdl.handle.net/10388/8584.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Hosseini Kalajahi, Seyed Mehrdad 1987-. “ADDRESSING PARTIAL VOLUME ARTIFACTS WITH QUANTITATIVE COMPUTED TOMOGRAPHY-BASED FINITE ELEMENT MODELING OF THE HUMAN PROXIMAL TIBIA.” 2018. Web. 17 Jan 2021.
Vancouver:
Hosseini Kalajahi SM1. ADDRESSING PARTIAL VOLUME ARTIFACTS WITH QUANTITATIVE COMPUTED TOMOGRAPHY-BASED FINITE ELEMENT MODELING OF THE HUMAN PROXIMAL TIBIA. [Internet] [Thesis]. University of Saskatchewan; 2018. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/10388/8584.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Hosseini Kalajahi SM1. ADDRESSING PARTIAL VOLUME ARTIFACTS WITH QUANTITATIVE COMPUTED TOMOGRAPHY-BASED FINITE ELEMENT MODELING OF THE HUMAN PROXIMAL TIBIA. [Thesis]. University of Saskatchewan; 2018. Available from: http://hdl.handle.net/10388/8584
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Penn State University
24.
Nelson, Cameron Stuart.
A Higher-Order Numerical Method for Solid Conductive Heat Transfer.
Degree: 2016, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/28757
► This thesis details the development of a higher-order numerical finite volume method for solid conductive heat transfer. Important thermodynamic and mathematical principles applied are conservation…
(more)
▼ This thesis details the development of a higher-order numerical
finite volume method for solid conductive heat transfer. Important thermodynamic and mathematical principles applied are conservation of energy, the heat diffusion equation, Fourier’s Law, the thermal contact resistance concept, Taylor series expansion, and the first-order backward Euler time-differencing method. The higher-order method turns out to be second-order accurate in space and third-order accurate in time with respect to temperature.
Advisors/Committee Members: John Michael Cimbala, Thesis Advisor/Co-Advisor, Daniel Connell Haworth, Thesis Advisor/Co-Advisor.
Subjects/Keywords: higher-order; finite volume; numerical; conduction; heat transfer
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APA (6th Edition):
Nelson, C. S. (2016). A Higher-Order Numerical Method for Solid Conductive Heat Transfer. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/28757
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):
Nelson, Cameron Stuart. “A Higher-Order Numerical Method for Solid Conductive Heat Transfer.” 2016. Thesis, Penn State University. Accessed January 17, 2021.
https://submit-etda.libraries.psu.edu/catalog/28757.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nelson, Cameron Stuart. “A Higher-Order Numerical Method for Solid Conductive Heat Transfer.” 2016. Web. 17 Jan 2021.
Vancouver:
Nelson CS. A Higher-Order Numerical Method for Solid Conductive Heat Transfer. [Internet] [Thesis]. Penn State University; 2016. [cited 2021 Jan 17].
Available from: https://submit-etda.libraries.psu.edu/catalog/28757.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nelson CS. A Higher-Order Numerical Method for Solid Conductive Heat Transfer. [Thesis]. Penn State University; 2016. Available from: https://submit-etda.libraries.psu.edu/catalog/28757
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Rice University
25.
Doyle, Bryan.
A Hybrid Numerical Scheme for Immiscible Two-Phase Flow.
Degree: PhD, Engineering, 2020, Rice University
URL: http://hdl.handle.net/1911/108783
► This thesis proposes a hybrid numerical scheme for immiscible, two-phase flow in porous media, for two separate partial differential equation (PDE) formulations. Discontinuous Galerkin (DG)…
(more)
▼ This thesis proposes a hybrid numerical scheme for immiscible, two-phase flow in porous media, for two separate partial differential equation (PDE) formulations. Discontinuous Galerkin (DG) methods are a commonly used numerical scheme in
such applications due to their local mass conservation and ability to handle discontinuous coefficients. Another popular choice are fi nite
volume (FV) methods, which are computationally cheaper than their DG counterparts but are only first order
accurate and struggle when discontinuous coefficients are introduced. The proposed hybrid numerical scheme uses the DG method in areas of the domain where accuracy is important or around regions where coefficients are discontinuous, and the FV method in all other areas. Preliminary numerical results show that such a hybrid
method produces similar results to the standard DG and FV methods in cases of homogeneous and heterogeneous
fluid flow, at a fraction of the computational cost. Applications of this work include simulating the quarter- five spot validation test and the channel-flow problem.
Advisors/Committee Members: Riviere, Beatrice (advisor).
Subjects/Keywords: discontinuous Galerkin; finite volume; immiscible; multiphase; deadoil; numerical scheme
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APA (6th Edition):
Doyle, B. (2020). A Hybrid Numerical Scheme for Immiscible Two-Phase Flow. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/108783
Chicago Manual of Style (16th Edition):
Doyle, Bryan. “A Hybrid Numerical Scheme for Immiscible Two-Phase Flow.” 2020. Doctoral Dissertation, Rice University. Accessed January 17, 2021.
http://hdl.handle.net/1911/108783.
MLA Handbook (7th Edition):
Doyle, Bryan. “A Hybrid Numerical Scheme for Immiscible Two-Phase Flow.” 2020. Web. 17 Jan 2021.
Vancouver:
Doyle B. A Hybrid Numerical Scheme for Immiscible Two-Phase Flow. [Internet] [Doctoral dissertation]. Rice University; 2020. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/1911/108783.
Council of Science Editors:
Doyle B. A Hybrid Numerical Scheme for Immiscible Two-Phase Flow. [Doctoral Dissertation]. Rice University; 2020. Available from: http://hdl.handle.net/1911/108783
University of Wollongong
26.
Wanayalage, Chandrasiri Kumara.
Load-deformation behaviour of rough rock fractures subjected to internal water flow.
Degree: PhD, 2014, University of Wollongong
URL: 090501
Civil
Geotechnical
Engineering,
010302
Numerical
Solution
of
Differential
and
Integral
Equations,
0403
GEOLOGY,
0404
GEOPHYSICS
;
https://ro.uow.edu.au/theses/4136
► Underground rock strata are often fractured and their permeability is mainly governed by interconnected fracture networks. Flow through fractures must be studied in order…
(more)
▼ Underground rock strata are often fractured and their permeability is mainly governed by interconnected fracture networks. Flow through fractures must be studied in order to design and operate underground activities such as tunnelling and mine operations, as well as groundwater and petroleum extraction. Flow through a fracture is primarily influenced by its aperture, and because fracture apertures can be distributed widely within a rockmass, they have closures as well as wide openings depending on the location and in-situ stress conditions. Past research studies have been carried out on defining the equivalent aperture to predict fracture flows from uni-directional flow models. However, in most civil engineering applications, plane strain conditions can be assumed (e.g. tunnels, rock slopes), and in such situations two-dimensional fracture models have been suggested for stationary fracture walls. Modelling flow through deformable fractures in plane stain, two-dimensional domain would provide profound insight into rock fracture hydraulics, and these models available now have been simulated using common numerical flow solvers. In this regard, a customised numerical solver to simulate fracture hydraulics would be an important addition to this research area.
In contrast to available literature, in this PhD study, an equivalent twodimensional flow model was derived from the three-dimensional Navier-Stokes theory for deformable rock fractures. The proposed model contains pressure-velocity coupled equations, and a numerical solution is subsequently introduced by modifying the SIMPLE (Semi Implicit Method for Pressure Linked Equations) algorithm. The Writer’s own computer programme (Rock Fracture Flow Solver or RFFS) was developed to solve the proposed model using MATLAB computer language. Laboratory experiments were carried out for mated and dislocated fracture specimens using the high pressure triaxial apparatus (HPTPTA) designed and built in University of Wollongong. The fracture apertures were measured by replicating them and scanning the surfaces using a 3D laser scanner. Flows through the rock fractures were simulated using the Rock Fracture Flow Solver (RFFS), and the validity of the proposed model was verified for general underground fracture flow situations.
Subjects/Keywords: fracture permeability; fluid flow; aperture distribution; triaxial testing; finite volume method
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APA (6th Edition):
Wanayalage, C. K. (2014). Load-deformation behaviour of rough rock fractures subjected to internal water flow. (Doctoral Dissertation). University of Wollongong. Retrieved from 090501 Civil Geotechnical Engineering, 010302 Numerical Solution of Differential and Integral Equations, 0403 GEOLOGY, 0404 GEOPHYSICS ; https://ro.uow.edu.au/theses/4136
Chicago Manual of Style (16th Edition):
Wanayalage, Chandrasiri Kumara. “Load-deformation behaviour of rough rock fractures subjected to internal water flow.” 2014. Doctoral Dissertation, University of Wollongong. Accessed January 17, 2021.
090501 Civil Geotechnical Engineering, 010302 Numerical Solution of Differential and Integral Equations, 0403 GEOLOGY, 0404 GEOPHYSICS ; https://ro.uow.edu.au/theses/4136.
MLA Handbook (7th Edition):
Wanayalage, Chandrasiri Kumara. “Load-deformation behaviour of rough rock fractures subjected to internal water flow.” 2014. Web. 17 Jan 2021.
Vancouver:
Wanayalage CK. Load-deformation behaviour of rough rock fractures subjected to internal water flow. [Internet] [Doctoral dissertation]. University of Wollongong; 2014. [cited 2021 Jan 17].
Available from: 090501 Civil Geotechnical Engineering, 010302 Numerical Solution of Differential and Integral Equations, 0403 GEOLOGY, 0404 GEOPHYSICS ; https://ro.uow.edu.au/theses/4136.
Council of Science Editors:
Wanayalage CK. Load-deformation behaviour of rough rock fractures subjected to internal water flow. [Doctoral Dissertation]. University of Wollongong; 2014. Available from: 090501 Civil Geotechnical Engineering, 010302 Numerical Solution of Differential and Integral Equations, 0403 GEOLOGY, 0404 GEOPHYSICS ; https://ro.uow.edu.au/theses/4136
University of Manitoba
27.
Jeffrey, Ian.
Finite-volume simulations of Maxwell's equations on unstructured grids.
Degree: Electrical and Computer Engineering, 2011, University of Manitoba
URL: http://hdl.handle.net/1993/4459
► Herein a fully parallel, upwind and flux-split Finite-Volume Time-Domain (FVTD) numerical engine for solving Maxwell's Equations on unstructured grids is developed. The required background theory…
(more)
▼ Herein a fully parallel, upwind and flux-split
Finite-
Volume Time-Domain (FVTD) numerical engine for solving Maxwell's Equations on unstructured grids is developed. The required background theory for solving Maxwell's Equations using FVTD is given in sufficient detail, including a description of both the temporal and spatial approximations used. The details of the local-time stepping strategy of Fumeaux et al. is included. A global mesh-truncation scheme using field integration over a Huygens' surface is also presented.
The capabilities of the FVTD algorithm are augmented with thin-wire and subcell circuit models that permit very flexible and accurate simulations of circuit-driven wire structures. Numerical and experimental validation shows that the proposed models have a wide-range of applications. Specifically, it appears that the thin-wire and subcell circuit models may be very well suited to the simulation of radio-frequency coils used in magnetic resonance imaging systems.
A parallelization scheme for the volumetric field solver, combined with the local-time stepping, global mesh-truncation and subcell models is developed that theoretically provides both linear time- and memory scaling in a distributed parallel environment.
Finally, the FVTD code is converted to the frequency domain and the possibility of using different flux-reconstruction schemes to improve the iterative convergence of the
Finite-
Volume Frequency-Domain algorithm is investigated.
Advisors/Committee Members: LoVetri, Joe (Electrical and Computer Engineering) (supervisor), Okhmatovski, Vladimir (Electrical and Computer Engineering) Bridges, Greg (Electrical and Computer Engineering) Lui, Shaun (Mathematics) So, Poman (Electrical and Computer Engineering University of Victoria) (examiningcommittee).
Subjects/Keywords: Finite-volume; Maxwell's equations; Numerical methods; Electromagnetics; Subcell models
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Manager
APA (6th Edition):
Jeffrey, I. (2011). Finite-volume simulations of Maxwell's equations on unstructured grids. (Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/4459
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):
Jeffrey, Ian. “Finite-volume simulations of Maxwell's equations on unstructured grids.” 2011. Thesis, University of Manitoba. Accessed January 17, 2021.
http://hdl.handle.net/1993/4459.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Jeffrey, Ian. “Finite-volume simulations of Maxwell's equations on unstructured grids.” 2011. Web. 17 Jan 2021.
Vancouver:
Jeffrey I. Finite-volume simulations of Maxwell's equations on unstructured grids. [Internet] [Thesis]. University of Manitoba; 2011. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/1993/4459.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Jeffrey I. Finite-volume simulations of Maxwell's equations on unstructured grids. [Thesis]. University of Manitoba; 2011. Available from: http://hdl.handle.net/1993/4459
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Manitoba
28.
Liu, Qingfan.
Field measurement and finite element simulation of pavement responses to standard and reduced tire pressure.
Degree: Civil Engineering, 2011, University of Manitoba
URL: http://hdl.handle.net/1993/4463
► To evaluate the impact of reduced truck tire pressure on strain response of low volume spring-restricted roads, research was conducted on two instrumented pavement sections…
(more)
▼ To evaluate the impact of reduced truck tire pressure on strain response of low
volume spring-restricted roads, research was conducted on two instrumented pavement sections in Manitoba, Canada. Tire pressure control systems tests were carried out at the sections in spring and fall 2009.
Measured maximum tensile strain at the bottom of asphalt layer decreased by 15-20% when tire pressure was reduced by 50%. Measured strain at the bottom of asphalt layer in fall is about 50% less than in spring. The effects of gauge orientation, truck speed, and tire offset from the strain gauge were also analyzed. A
finite element model with static load was developed and verified.
The bearing capacity is lower in spring than in normal condition for flexible pavements
subject to deep frost action. Reduced tire pressure is effective to reduce bottom up failure of the pavement, and is less effective to prevent rutting.
Advisors/Committee Members: Shalaby, Ahmed (Civil Engineering) (supervisor), Clayton, Alan (Civil Engineering) Luo, Yunhua (Mechanical and Manufacturing Engineering) (examiningcommittee).
Subjects/Keywords: low-volume road; spring load restriction; instrumentation; finite element analysis
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APA ·
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Manager
APA (6th Edition):
Liu, Q. (2011). Field measurement and finite element simulation of pavement responses to standard and reduced tire pressure. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/4463
Chicago Manual of Style (16th Edition):
Liu, Qingfan. “Field measurement and finite element simulation of pavement responses to standard and reduced tire pressure.” 2011. Masters Thesis, University of Manitoba. Accessed January 17, 2021.
http://hdl.handle.net/1993/4463.
MLA Handbook (7th Edition):
Liu, Qingfan. “Field measurement and finite element simulation of pavement responses to standard and reduced tire pressure.” 2011. Web. 17 Jan 2021.
Vancouver:
Liu Q. Field measurement and finite element simulation of pavement responses to standard and reduced tire pressure. [Internet] [Masters thesis]. University of Manitoba; 2011. [cited 2021 Jan 17].
Available from: http://hdl.handle.net/1993/4463.
Council of Science Editors:
Liu Q. Field measurement and finite element simulation of pavement responses to standard and reduced tire pressure. [Masters Thesis]. University of Manitoba; 2011. Available from: http://hdl.handle.net/1993/4463
Hong Kong University of Science and Technology
29.
Mesgari Sohani, Sara CIVL.
A framework for handling boundary conditions in waterhammer within Boltzmann-based finite volume methods.
Degree: 2015, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-94661
;
http://repository.ust.hk/ir/bitstream/1783.1-94661/1/th_redirect.html
► Planned transient waves can be beneficially used in the detection of defects in pipelines. Such applications show that the higher is the frequency of the…
(more)
▼ Planned transient waves can be beneficially used in the detection of defects in pipelines. Such applications show that the higher is the frequency of the injected wave the better is the detection. Finite volume (FV) methods have recently been applied to waterhammer problems and are known to be well suited for high frequency waves. However, FV methods are formulated for simple boundary conditions such no-flux or no-slip, but not for typical boundary conditions in pressurized pipeline systems (e.g., junctions, control valves, orifices, tanks, and reservoirs). In the instances in the literature where FV has been applied to waterhammer problems, the approach has been to use FV for internal sections and the Method of Characteristics (MOC) at the boundaries. This global order of accuracy of the FV-MOC is governed by the MOC solution. This thesis is a first attempt in handling boundary conditions within the FV framework. The approach places the boundary element within a FV to enforce mass and momentum conservation within this volume. The fluxes between the FV and the adjacent elements are then formulated in the usual manner. The approach is illustrated for the case of a valve, a reservoir and a junction. The finite volume method used is the Boltzmann-type scheme, which is a mesoscopic model. In particular, the 1st and 2nd-order collisionless Boltzmann-type scheme (i.e., the kinetic flux vector splitting (KFVS)) and the 2nd-order Bhatnagar-Gross-Krook (BGK) Boltzmann scheme are formulated and applied to one-dimensional transient flows. The accuracy and efficiency of all schemes with the proposed non-iterative FV formulation of the boundary conditions are demonstrated through the following test cases: (i) problems due to sudden closing of a valve, (ii) wave interactions with a junction boundary characterized by a geometric discontinuity, (iii) wave interactions with a junction boundary characterized by a discontinuity in the value of wave speed, and (iv) wave interactions with a junction characterized by a flow rate discontinuity. The pure FV formulation guarantees the mass and momentum conservation. The Boltzmann-based FV schemes capture the discontinuity as well as wave interaction with boundary elements accurately. The stability of the proposed FV schemes is satisfied when Cr < 0:5. The comparison between the efficiency of the conventional scheme (i.e., the Fix- MOC and Godunov schemes) and those of the mesoscopic-based schemes (i.e., the KFVS and BGK schemes) reveals that none of the proposed schemes is better than the 2nd-order Godunov scheme for classical waterhammer. Nevertheless, it is found that the CPU time needed by the 2nd-order BGK scheme to achieve a predefined degree of accuracy is not too far from that by the 2nd-order Godunov scheme. The KFVS scheme is more dissipative than the BGK scheme due to the lack of particle collisions in the formulation.
Subjects/Keywords: Water hammer
; Mathematical models
; Finite volume method
; Lattice Boltzmann methods
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APA (6th Edition):
Mesgari Sohani, S. C. (2015). A framework for handling boundary conditions in waterhammer within Boltzmann-based finite volume methods. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-94661 ; http://repository.ust.hk/ir/bitstream/1783.1-94661/1/th_redirect.html
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):
Mesgari Sohani, Sara CIVL. “A framework for handling boundary conditions in waterhammer within Boltzmann-based finite volume methods.” 2015. Thesis, Hong Kong University of Science and Technology. Accessed January 17, 2021.
http://repository.ust.hk/ir/Record/1783.1-94661 ; http://repository.ust.hk/ir/bitstream/1783.1-94661/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mesgari Sohani, Sara CIVL. “A framework for handling boundary conditions in waterhammer within Boltzmann-based finite volume methods.” 2015. Web. 17 Jan 2021.
Vancouver:
Mesgari Sohani SC. A framework for handling boundary conditions in waterhammer within Boltzmann-based finite volume methods. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2015. [cited 2021 Jan 17].
Available from: http://repository.ust.hk/ir/Record/1783.1-94661 ; http://repository.ust.hk/ir/bitstream/1783.1-94661/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mesgari Sohani SC. A framework for handling boundary conditions in waterhammer within Boltzmann-based finite volume methods. [Thesis]. Hong Kong University of Science and Technology; 2015. Available from: http://repository.ust.hk/ir/Record/1783.1-94661 ; http://repository.ust.hk/ir/bitstream/1783.1-94661/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
30.
Asadollahi, M. (author).
Finite Volume Method for Poroelasticity.
Degree: 2017, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:f1097b23-80da-4eda-8c94-58e033f730d8
► When modelling fluid fl ow in subsurface, the impact of solid deformation on fluid fl ow is often oversimplified/neglected in reservoir simulators. It is assumed…
(more)
▼ When modelling fluid fl ow in subsurface, the impact of solid deformation on fluid fl ow is often oversimplified/neglected in reservoir simulators. It is assumed that solid
volume/s-tate of stress is a function of fluid pressure, while the opposite effect is not considered. This assumption is made mainly to reduce computational costs and complexity of fl uid flow models. Nevertheless, this simplification is not valid in case of unconsolidated rocks. This oversimplification results in wrong estimation in prediction of surface subsidence, earthquakes and fault activation, fluid production and rock permeability values, etc. Numerous reports suggest that neglecting the two-way coupling (i.e. both fluid-to-solid and solid-to- fluid coupling ) has led to disastrous events in many cases. This necessitates modified fl uid models and simulators which take into account the two-way coupled nature of solid deformation and fl uid flow in porous media. Efforts have been made to model this two-way coupled nature properly which can be categorized as follows. There have been attempts to connect commercial softwares to model this problem. They fail due to differences in data structure, different underlying assumptions embedded and due to the increased computational costs. Therefore, it is essential to integrate fluid modelling and solid deformation into a single simulator. This requires developing new numerical models. Presuming an elastic nature for unconsolidated rocks, Biot's consolidation equations are employed to numerically model the two-way coupled solid deformation and fluid fl ow in porous media, so called poroelasticity. During my master work, I developed 2D MATLAB codes based on two different
finite volume discretization schemes (cell-centred and vertex-centred FVM). In the first stage, two cell-centred FVM 2D MATLAB codes were developed: One to model fluid flow, and one to model solid equations in poroelasticity. At the next stage, the two cell centred codes were iteratively coupled. Then, another 2D fully coupled model based on a vertex-centred
finite volume discretization scheme was developed for poroelasticity. The fl uid and solid data structure in both developed models are the same; in other words, unknowns are collocated. To verify and conduct error analysis on the developed
finite volume based simulators, 2D MATLAB codes for one classic benchmark problem in poroelasticity, namely the Mandel problem, as well as 2D MATLAB codes for synthetic test cases were developed. At the next stage, the performance of the two models is compared. Though both methods illustrate adequate performance, fully coupled
finite volume method is preferred. Finally, the reaction of the fully coupled
finite volume model to different systems, its performance under stress and displacement boundary condition configuration, sensitivity of the model to uncertainty of input parameters, robustness of the model, and applications of this method are being analysed. Furthermore, thorough discussion on enhancement of the model is provided. To our…
Advisors/Committee Members: Barnhoorn, A. (mentor).
Subjects/Keywords: finite volume method; fully coupled; sequentially coupled; poroelasticity
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APA ·
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APA (6th Edition):
Asadollahi, M. (. (2017). Finite Volume Method for Poroelasticity. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:f1097b23-80da-4eda-8c94-58e033f730d8
Chicago Manual of Style (16th Edition):
Asadollahi, M (author). “Finite Volume Method for Poroelasticity.” 2017. Masters Thesis, Delft University of Technology. Accessed January 17, 2021.
http://resolver.tudelft.nl/uuid:f1097b23-80da-4eda-8c94-58e033f730d8.
MLA Handbook (7th Edition):
Asadollahi, M (author). “Finite Volume Method for Poroelasticity.” 2017. Web. 17 Jan 2021.
Vancouver:
Asadollahi M(. Finite Volume Method for Poroelasticity. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 17].
Available from: http://resolver.tudelft.nl/uuid:f1097b23-80da-4eda-8c94-58e033f730d8.
Council of Science Editors:
Asadollahi M(. Finite Volume Method for Poroelasticity. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:f1097b23-80da-4eda-8c94-58e033f730d8
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Open Access Theses and Dissertations