Author: Joe Antoine Rached
Publisher:
ISBN:
Category :
Languages : en
Pages : 266
Book Description
The aim of this thesis is divided into two parts. The first part consists of imp lementing and testing the accuracy of polygonal grids in the Finite Volume Metho d (FVM) context, a method usually used in Computational Fluid Mechanics (CFD). T he use of polygonal elements instead of triangular or quadrilateral elements lie s behind the nature of the FVM, which adapts to any Control Volume (CV) shape. P ure advection and real flow test cases were conducted for this end. Results show ed that more insight should be made in developing a tailored differencing scheme to be used on polygonal grids. The accuracy was acceptable but the solution tim e was not enhanced. The second part of this thesis is to implement Adaptive Mesh Refinement (AMR) us ing the hanging nodes method, a technique that resolves cells in regions where n eeded. Since the computational cost is directly related to the number of element s used in the numerical simulation, AMR is capable of automatically refining the grid where large gradients are present and hence the accuracy of the solution i s increased with less computational cost and time, compared to uniform refinemen t. Mesh refinement alone is not sufficient because previously refined grids migh t not be needed anymore, especially in transient problems. To this end, a new me sh coarsening method was developed in order to decrease the density of the grid in regions where large gradients are not present anymore. AMR and Coarsening (AM RC) are usually implemented in a tree-structure, using a children-parent sort of linkage. In the developed method, the tree structure is abandoned and AMRC is d one locally without the need to store the history of the refined element. In order to speed up the simulation on adapted grids, a good initial guess on th e refined grid is needed. To this end, the solution of the original grid is mapp ed on the initial grid, leading to less time and computational cost in reaching a converged solution. Pure advection and real flow problems for fluid flows at a ll speeds where conducted. The method proves accuracy especially in the compress ible flow regime.
On the Accuracy of the Finite Volume Method on Polygonal Grids with Adaptive Mesh Refinement and Coarsening
Author: Joe Antoine Rached
Publisher:
ISBN:
Category :
Languages : en
Pages : 266
Book Description
The aim of this thesis is divided into two parts. The first part consists of imp lementing and testing the accuracy of polygonal grids in the Finite Volume Metho d (FVM) context, a method usually used in Computational Fluid Mechanics (CFD). T he use of polygonal elements instead of triangular or quadrilateral elements lie s behind the nature of the FVM, which adapts to any Control Volume (CV) shape. P ure advection and real flow test cases were conducted for this end. Results show ed that more insight should be made in developing a tailored differencing scheme to be used on polygonal grids. The accuracy was acceptable but the solution tim e was not enhanced. The second part of this thesis is to implement Adaptive Mesh Refinement (AMR) us ing the hanging nodes method, a technique that resolves cells in regions where n eeded. Since the computational cost is directly related to the number of element s used in the numerical simulation, AMR is capable of automatically refining the grid where large gradients are present and hence the accuracy of the solution i s increased with less computational cost and time, compared to uniform refinemen t. Mesh refinement alone is not sufficient because previously refined grids migh t not be needed anymore, especially in transient problems. To this end, a new me sh coarsening method was developed in order to decrease the density of the grid in regions where large gradients are not present anymore. AMR and Coarsening (AM RC) are usually implemented in a tree-structure, using a children-parent sort of linkage. In the developed method, the tree structure is abandoned and AMRC is d one locally without the need to store the history of the refined element. In order to speed up the simulation on adapted grids, a good initial guess on th e refined grid is needed. To this end, the solution of the original grid is mapp ed on the initial grid, leading to less time and computational cost in reaching a converged solution. Pure advection and real flow problems for fluid flows at a ll speeds where conducted. The method proves accuracy especially in the compress ible flow regime.
Publisher:
ISBN:
Category :
Languages : en
Pages : 266
Book Description
The aim of this thesis is divided into two parts. The first part consists of imp lementing and testing the accuracy of polygonal grids in the Finite Volume Metho d (FVM) context, a method usually used in Computational Fluid Mechanics (CFD). T he use of polygonal elements instead of triangular or quadrilateral elements lie s behind the nature of the FVM, which adapts to any Control Volume (CV) shape. P ure advection and real flow test cases were conducted for this end. Results show ed that more insight should be made in developing a tailored differencing scheme to be used on polygonal grids. The accuracy was acceptable but the solution tim e was not enhanced. The second part of this thesis is to implement Adaptive Mesh Refinement (AMR) us ing the hanging nodes method, a technique that resolves cells in regions where n eeded. Since the computational cost is directly related to the number of element s used in the numerical simulation, AMR is capable of automatically refining the grid where large gradients are present and hence the accuracy of the solution i s increased with less computational cost and time, compared to uniform refinemen t. Mesh refinement alone is not sufficient because previously refined grids migh t not be needed anymore, especially in transient problems. To this end, a new me sh coarsening method was developed in order to decrease the density of the grid in regions where large gradients are not present anymore. AMR and Coarsening (AM RC) are usually implemented in a tree-structure, using a children-parent sort of linkage. In the developed method, the tree structure is abandoned and AMRC is d one locally without the need to store the history of the refined element. In order to speed up the simulation on adapted grids, a good initial guess on th e refined grid is needed. To this end, the solution of the original grid is mapp ed on the initial grid, leading to less time and computational cost in reaching a converged solution. Pure advection and real flow problems for fluid flows at a ll speeds where conducted. The method proves accuracy especially in the compress ible flow regime.
Adaptive Mesh Refinement - Theory and Applications
Author: Tomasz Plewa
Publisher: Springer Science & Business Media
ISBN: 3540270396
Category : Mathematics
Languages : en
Pages : 550
Book Description
Advanced numerical simulations that use adaptive mesh refinement (AMR) methods have now become routine in engineering and science. Originally developed for computational fluid dynamics applications these methods have propagated to fields as diverse as astrophysics, climate modeling, combustion, biophysics and many others. The underlying physical models and equations used in these disciplines are rather different, yet algorithmic and implementation issues facing practitioners are often remarkably similar. Unfortunately, there has been little effort to review the advances and outstanding issues of adaptive mesh refinement methods across such a variety of fields. This book attempts to bridge this gap. The book presents a collection of papers by experts in the field of AMR who analyze past advances in the field and evaluate the current state of adaptive mesh refinement methods in scientific computing.
Publisher: Springer Science & Business Media
ISBN: 3540270396
Category : Mathematics
Languages : en
Pages : 550
Book Description
Advanced numerical simulations that use adaptive mesh refinement (AMR) methods have now become routine in engineering and science. Originally developed for computational fluid dynamics applications these methods have propagated to fields as diverse as astrophysics, climate modeling, combustion, biophysics and many others. The underlying physical models and equations used in these disciplines are rather different, yet algorithmic and implementation issues facing practitioners are often remarkably similar. Unfortunately, there has been little effort to review the advances and outstanding issues of adaptive mesh refinement methods across such a variety of fields. This book attempts to bridge this gap. The book presents a collection of papers by experts in the field of AMR who analyze past advances in the field and evaluate the current state of adaptive mesh refinement methods in scientific computing.
A Freestream-Preserving High-Order Finite-Volume Method for Mapped Grids with Adaptive-Mesh Refinement
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
A fourth-order accurate finite-volume method is presented for solving time-dependent hyperbolic systems of conservation laws on mapped grids that are adaptively refined in space and time. Novel considerations for formulating the semi-discrete system of equations in computational space combined with detailed mechanisms for accommodating the adapting grids ensure that conservation is maintained and that the divergence of a constant vector field is always zero (freestream-preservation property). Advancement in time is achieved with a fourth-order Runge-Kutta method.
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
A fourth-order accurate finite-volume method is presented for solving time-dependent hyperbolic systems of conservation laws on mapped grids that are adaptively refined in space and time. Novel considerations for formulating the semi-discrete system of equations in computational space combined with detailed mechanisms for accommodating the adapting grids ensure that conservation is maintained and that the divergence of a constant vector field is always zero (freestream-preservation property). Advancement in time is achieved with a fourth-order Runge-Kutta method.
Surface Modeling, Grid Generation, and Related Issues in Computational Fluid Dynamic (CFD) Solutions
Author:
Publisher:
ISBN:
Category : Airframes
Languages : en
Pages : 876
Book Description
Publisher:
ISBN:
Category : Airframes
Languages : en
Pages : 876
Book Description
High-Order WENO Finite Volume Methods on Cartesian Grids with Adaptive Mesh Refinement
Author: Pawel Buchmüller
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Grid-quality Measures for Error Estimation and Solution-adaptive Mesh Refinement in CFD
Author: Xubin Gu
Publisher:
ISBN:
Category : Fluid dynamic measurements
Languages : en
Pages : 488
Book Description
Publisher:
ISBN:
Category : Fluid dynamic measurements
Languages : en
Pages : 488
Book Description
Parallel Anisotropic Block-Based Adaptive Mesh Refinement Finite-Volume Scheme
Author: Jenmy Zimi Zhang
Publisher:
ISBN: 9780494766118
Category :
Languages : en
Pages : 224
Book Description
A novel anisotropic adaptive mesh refinement (AMR) technique is proposed and de- scribed. A block-based AMR approach is used which permits highly efficient and scalable implementations on parallel computer architectures and the use of multi-block, body-fitted computational grids for the treatment of complex geometries. However, rather than adopting the more usual isotropic approach to the refinement of the grid blocks, the proposed approach uses a binary hierarchical tree data structure that allows for anisotropic refinement of the grid blocks in each of the coordinate directions in an inde- pendent fashion. This allows for more efficient and accurate treatment of narrow layers, discontinuities, and/or shocks in the solutions which occur, for example, in the thin boundary and mixing layers of high-Reynolds-number viscous flows and in the regions of strong non-linear wave interactions of high-speed compressible flows with shocks. The anisotropic AMR technique is implemented within an existing finite-volume framework, which encompasses both explicit and implicit solution methods, and is capable of per- forming calculations with both second- and higher-order spatial accuracy. To clearly demonstrate the potential and feasibility of the proposed AMR technique, it is applied to the unsteady and steady-state solutions of both a model system, the advection diffusion equation, as well as the Euler equations governing compressible, inviscid, gaseous flows, both in two space dimensions.
Publisher:
ISBN: 9780494766118
Category :
Languages : en
Pages : 224
Book Description
A novel anisotropic adaptive mesh refinement (AMR) technique is proposed and de- scribed. A block-based AMR approach is used which permits highly efficient and scalable implementations on parallel computer architectures and the use of multi-block, body-fitted computational grids for the treatment of complex geometries. However, rather than adopting the more usual isotropic approach to the refinement of the grid blocks, the proposed approach uses a binary hierarchical tree data structure that allows for anisotropic refinement of the grid blocks in each of the coordinate directions in an inde- pendent fashion. This allows for more efficient and accurate treatment of narrow layers, discontinuities, and/or shocks in the solutions which occur, for example, in the thin boundary and mixing layers of high-Reynolds-number viscous flows and in the regions of strong non-linear wave interactions of high-speed compressible flows with shocks. The anisotropic AMR technique is implemented within an existing finite-volume framework, which encompasses both explicit and implicit solution methods, and is capable of per- forming calculations with both second- and higher-order spatial accuracy. To clearly demonstrate the potential and feasibility of the proposed AMR technique, it is applied to the unsteady and steady-state solutions of both a model system, the advection diffusion equation, as well as the Euler equations governing compressible, inviscid, gaseous flows, both in two space dimensions.
AIAA Journal
Author: American Institute of Aeronautics and Astronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1364
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1364
Book Description
The Finite Volume Method in Computational Fluid Dynamics
Author: F. Moukalled
Publisher: Springer
ISBN: 3319168746
Category : Technology & Engineering
Languages : en
Pages : 799
Book Description
This textbook explores both the theoretical foundation of the Finite Volume Method (FVM) and its applications in Computational Fluid Dynamics (CFD). Readers will discover a thorough explanation of the FVM numerics and algorithms used for the simulation of incompressible and compressible fluid flows, along with a detailed examination of the components needed for the development of a collocated unstructured pressure-based CFD solver. Two particular CFD codes are explored. The first is uFVM, a three-dimensional unstructured pressure-based finite volume academic CFD code, implemented within Matlab. The second is OpenFOAM®, an open source framework used in the development of a range of CFD programs for the simulation of industrial scale flow problems. With over 220 figures, numerous examples and more than one hundred exercise on FVM numerics, programming, and applications, this textbook is suitable for use in an introductory course on the FVM, in an advanced course on numerics, and as a reference for CFD programmers and researchers.
Publisher: Springer
ISBN: 3319168746
Category : Technology & Engineering
Languages : en
Pages : 799
Book Description
This textbook explores both the theoretical foundation of the Finite Volume Method (FVM) and its applications in Computational Fluid Dynamics (CFD). Readers will discover a thorough explanation of the FVM numerics and algorithms used for the simulation of incompressible and compressible fluid flows, along with a detailed examination of the components needed for the development of a collocated unstructured pressure-based CFD solver. Two particular CFD codes are explored. The first is uFVM, a three-dimensional unstructured pressure-based finite volume academic CFD code, implemented within Matlab. The second is OpenFOAM®, an open source framework used in the development of a range of CFD programs for the simulation of industrial scale flow problems. With over 220 figures, numerous examples and more than one hundred exercise on FVM numerics, programming, and applications, this textbook is suitable for use in an introductory course on the FVM, in an advanced course on numerics, and as a reference for CFD programmers and researchers.
Block-Based Adaptive Mesh Refinement Finite-Volume Scheme for Hybrid Multi-Block Meshes
Author: Jason Z. X. Zheng
Publisher:
ISBN: 9780494929377
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN: 9780494929377
Category :
Languages : en
Pages :
Book Description