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You searched for subject:(Immersed interfaces). Showing records 1 – 3 of 3 total matches.

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Université Catholique de Louvain

1. Quan, Dieu Linh. A mesh-based technique for solving CFD problems with embedded geometries : anisotropic adaptive "nearly" body-fitted mesh approach.

Degree: 2014, Université Catholique de Louvain

Embedded geometry is a family of techniques dedicated to engineering problems involving remeshing on the fly during the simulation, or mesh generation in complex geometries. Embedded geometry has gained attention over the recent years due to its ability to shift a significant part of the burden of the geometrical description and/or discretization from the CAD tool to the simulation tool. The work presented in this thesis has led to a “purely” mesh-based technique to handle immersed geometries in Computational Fluid Dynamic problems. The proposed technique relies upon anisotropic mesh adaptivity in the vicinity of the embedded interface. The mesh adaptation is driven by the Hessian of the flow solution, and it contributes to improve the accuracy of the computation. An overview of existing methods for handling embedded geometry is given in the first part of the thesis. The state-of-the-art is discussed and existing trends for the treatment of immersed boundaries and immersed domains are reviewed and analysed in details, in order to pave the way for the proposed technique. In the context of the advocated ”nearly” body-fitted mesh approach, the use of very-large anisotropic elements in the vicinity of the interface results in an approximated interface, playing the role of an embedded boundary during simulation. Error analysis shows that an optimal rate of convergence can be recovered by a careful mesh size choice in the direction normal to the interface. The last part of the thesis deals with the application of the method to a number of Computational Fluid Dynamics problems, with the emphasis on immersed no-slip walls. The obtained results are shown to be in good agreement with reference studies by other authors, indicating that the proposed technique is an accurate, robust and convenient approach to solving CFD problems with embedded geometries.

(FSA - Sciences de l)  – UCL, 2014

Advisors/Committee Members: UCL - SST / IMMC / MEMA - Applied mathematics and mechanics, UCL - Ecole Polytechnique de Louvain, Remacle, Jean-Francois, Marchandise, Emilie, Winckelmans, Gregoire, Legat, Vincent, Chatelain, Philippe, Geuzaine, Christophe, Hachem, Elie.

Subjects/Keywords: Level-set; Anisotropic adaptivity; Mesh-based technique; Embedded geometries; Immersed interfaces

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Quan, D. L. (2014). A mesh-based technique for solving CFD problems with embedded geometries : anisotropic adaptive "nearly" body-fitted mesh approach. (Thesis). Université Catholique de Louvain. Retrieved from http://hdl.handle.net/2078.1/154134

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):

Quan, Dieu Linh. “A mesh-based technique for solving CFD problems with embedded geometries : anisotropic adaptive "nearly" body-fitted mesh approach.” 2014. Thesis, Université Catholique de Louvain. Accessed October 22, 2019. http://hdl.handle.net/2078.1/154134.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Quan, Dieu Linh. “A mesh-based technique for solving CFD problems with embedded geometries : anisotropic adaptive "nearly" body-fitted mesh approach.” 2014. Web. 22 Oct 2019.

Vancouver:

Quan DL. A mesh-based technique for solving CFD problems with embedded geometries : anisotropic adaptive "nearly" body-fitted mesh approach. [Internet] [Thesis]. Université Catholique de Louvain; 2014. [cited 2019 Oct 22]. Available from: http://hdl.handle.net/2078.1/154134.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Quan DL. A mesh-based technique for solving CFD problems with embedded geometries : anisotropic adaptive "nearly" body-fitted mesh approach. [Thesis]. Université Catholique de Louvain; 2014. Available from: http://hdl.handle.net/2078.1/154134

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Paino, Paulo Celso Vieira. Análise de desempenho de um método de interfaces imersas de alta ordem.

Degree: Mestrado, Aeronaves, 2011, University of São Paulo

No contexto de Dinâmica de Fluidos Computacional, métodos de simulação de objetos imersos em Malhas Cartesianas têm se mostrado vantajosos tanto em termos de Custo Computacional quanto em termos de precisão numérica. Entretanto, a representação física de objetos imersos nesses domínios computacionais impõe a perda de validade dos esquemas de Diferenças Finitas empregados, na região das superfícies introduzidas. Este trabalho analisa um Método de Interfaces Imersas quanto ao desempenho em aplicações a esquemas de solução numérica de Alta Ordem de precisão. Através de Testes de Refinamento de Malha, é feita a apreciação da ordem de decaimento dos erros das soluções numéricas em comparação com as soluções analíticas para 2 problemas unidimensionais. O primeiro envolve a solução da Equação de Calor unidimensional sujeita a uma Condição Inicial Unitária, e o segundo relaciona-se ao cálculo das duas primeiras derivadas espaciais das funções analíticas Seno e Tangente Hiperbólica. Também é promovida uma análise de forma fragmentária do método, a fim de individualizar a contribuição dos elementos envolvidos no comportamento das soluções geradas. Os resultados obtidos indicam eventuais alterações na ordem de precisão dos esquemas de Diferenças Finitas originalmente aplicados. Esse comportamento e visto como uma dependência que o método escolhido apresenta em relação a função discretizada. Por fim, são elaboradas considerações sobre restrições de aplicabilidade do método escolhido.

In the Computational Fluid Dynamics context, methods for simulating immersed objects in Cartesian Grids have shown advantages regarding both Computational Cost and numerical precision. Nevertheless, the physical representation of immersed objects within these computational domains leads to the loss of validity of the emplyed Finite Dierence Schemes near the immersed surfaces. This work analizes a Immersed Interface Method regarding its performance in High Order Schemes applications. The error decay order for numerical solutions of two 1D problems is observed. The rst problem relates to the solution of the Heat Equation subjected to the unitary initial condition. The second relates to the computation of the rst two derivatives of analytical functions Sin and Hyperbolic Tangent. It\'s also conducted a fragmentary analysis, which is intended to identify the contribution of each element of this method to the character of the generated solution. The results indicate some eventual changes in the Order of the Finite Dierences Schemes employed. This behaviour is regarded as a dependency of this method to the nature of the discretized function. Finaly, some remarks regarding restrictions to this method\'s applicability are made.

Advisors/Committee Members: Medeiros, Marcello Augusto Faraco de.

Subjects/Keywords: CFD; CFD; Esquemas de alta ordem; High order schemes; Immersed boundaries method; Immersed interface method; Métodos de fronteiras imersas; Métodos de interfaces imersas.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Paino, P. C. V. (2011). Análise de desempenho de um método de interfaces imersas de alta ordem. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/18/18148/tde-24072013-132604/ ;

Chicago Manual of Style (16th Edition):

Paino, Paulo Celso Vieira. “Análise de desempenho de um método de interfaces imersas de alta ordem.” 2011. Masters Thesis, University of São Paulo. Accessed October 22, 2019. http://www.teses.usp.br/teses/disponiveis/18/18148/tde-24072013-132604/ ;.

MLA Handbook (7th Edition):

Paino, Paulo Celso Vieira. “Análise de desempenho de um método de interfaces imersas de alta ordem.” 2011. Web. 22 Oct 2019.

Vancouver:

Paino PCV. Análise de desempenho de um método de interfaces imersas de alta ordem. [Internet] [Masters thesis]. University of São Paulo; 2011. [cited 2019 Oct 22]. Available from: http://www.teses.usp.br/teses/disponiveis/18/18148/tde-24072013-132604/ ;.

Council of Science Editors:

Paino PCV. Análise de desempenho de um método de interfaces imersas de alta ordem. [Masters Thesis]. University of São Paulo; 2011. Available from: http://www.teses.usp.br/teses/disponiveis/18/18148/tde-24072013-132604/ ;


North Carolina State University

3. Yang, Xingzhou. Immersed Interface Method for Elasticity Problems with Interfaces.

Degree: PhD, Applied Mathematics, 2004, North Carolina State University

An immersed interface method and an immersed finite element method for solving linear elasticity problems with two phases separated by an interface have been developed in this thesis. For the problem of interest, the underlying elasticity modulus is a constant in each phase but vary from phase to phase. The basic goal here is to design an efficient numerical method using a fixed Cartesian grid. The application of such a method to problems with moving interfaces driving by stresses has a great advantage: no re-meshing is needed. A local optimization strategy is employed to determine the finite difference equations at grid points near or on the interface. The bi-conjugate gradient method and the GMRES with preconditioning are both implemented to solve the resulting linear systems of equations and compared. The level set method is used to represent the interface. Numerical results are presented to show that the immersed interface method is second-order accurate. Advisors/Committee Members: Dr. Mansoor A. Haider, Committee Member (advisor), Dr. Kazufumi Ito, Committee Member (advisor), Dr. Sharon R. Lubkin, Committee Member (advisor), Dr. Zhilin Li, Committee Chair (advisor), Computational Mathematics (advisor).

Subjects/Keywords: finite differences; the immersed interface method; jump conditions; interfaces; Elasticity; optimization solvers.; PCG; GMRES; preconditioned BICGSTAB; stress; strain; Galerkin method; energy form; variation form; level set method; Cartesian grids method; Gaussian quadrature; immersed finite element method

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Yang, X. (2004). Immersed Interface Method for Elasticity Problems with Interfaces. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/5035

Chicago Manual of Style (16th Edition):

Yang, Xingzhou. “Immersed Interface Method for Elasticity Problems with Interfaces.” 2004. Doctoral Dissertation, North Carolina State University. Accessed October 22, 2019. http://www.lib.ncsu.edu/resolver/1840.16/5035.

MLA Handbook (7th Edition):

Yang, Xingzhou. “Immersed Interface Method for Elasticity Problems with Interfaces.” 2004. Web. 22 Oct 2019.

Vancouver:

Yang X. Immersed Interface Method for Elasticity Problems with Interfaces. [Internet] [Doctoral dissertation]. North Carolina State University; 2004. [cited 2019 Oct 22]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5035.

Council of Science Editors:

Yang X. Immersed Interface Method for Elasticity Problems with Interfaces. [Doctoral Dissertation]. North Carolina State University; 2004. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5035

.