sunfluidh:numerical_methods_examples
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Ci-dessous, les différences entre deux révisions de la page.
Les deux révisions précédentesRévision précédenteProchaine révision | Révision précédente | ||
sunfluidh:numerical_methods_examples [2017/09/25 16:01] – yann | sunfluidh:numerical_methods_examples [2018/12/01 16:43] (Version actuelle) – [Example 2 : An iterative method coupled with a multigrid procedure using a in-house development] yann | ||
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===== Some examples illustrating how to use the relevant namelists to set the numerical methods for solving the equations ===== | ===== Some examples illustrating how to use the relevant namelists to set the numerical methods for solving the equations ===== | ||
- | ==== Context : Heat driven incompressible flow ==== | + | [[new_numerical_methods_setup_namelist |Click here to come back to the previous page]] |
+ | ==== Context : Heat driven incompressible flow ==== | ||
+ | <WRAP info> | ||
* Numerical scheme for solving the governing equations of velocity and temperature | * Numerical scheme for solving the governing equations of velocity and temperature | ||
* Time discretization : semi-implicit formulation with the 2nd order Backward Differentiation formula (BDF2) | * Time discretization : semi-implicit formulation with the 2nd order Backward Differentiation formula (BDF2) | ||
Ligne 8: | Ligne 10: | ||
* convective flux for momentum equation : 2nd order centered scheme, conservative form | * convective flux for momentum equation : 2nd order centered scheme, conservative form | ||
* advective flux for temperature equation : 2nd order centered scheme, conservative form | * advective flux for temperature equation : 2nd order centered scheme, conservative form | ||
- | * Solving Poisson' | + | * Solving Poisson' |
+ | </ | ||
==== Example 1 : Partial diagonalization method ==== | ==== Example 1 : Partial diagonalization method ==== | ||
Ligne 28: | Ligne 31: | ||
| | ||
- | ==== Example 2 : An iterative method coupled with a multigrid procedure | + | ==== Example 2 : An iterative method coupled with a multigrid procedure |
+ | |||
+ | <WRAP info> | ||
Suitable setting : | Suitable setting : | ||
Ligne 39: | Ligne 44: | ||
* 15 on the prolongation step (going from coarsest to the finnest grid) | * 15 on the prolongation step (going from coarsest to the finnest grid) | ||
* The stopping criterion based on the residu of the computation is 1E-08 | * The stopping criterion based on the residu of the computation is 1E-08 | ||
- | | + | </ |
- | As the fluid is incompressible, | + | As the fluid is incompressible, |
As a " | As a " | ||
- | * Using the namelist " | + | * Using the namelist " |
- | * Using the namelists " | + | * Using the namelists " |
- | + | ||
- | === Using the namelist " | + | |
- | The old version | + | === Using the namelist " |
+ | |||
| | ||
& | & | ||
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Convergence_Criterion | Convergence_Criterion | ||
| | ||
- | The corresponding | + | === Using the namelists " |
& | & | ||
MomentumConvection_Scheme=" | MomentumConvection_Scheme=" | ||
TemperatureAdvection_Scheme=" | TemperatureAdvection_Scheme=" | ||
- | Poisson_NumericalMethod=" | + | Poisson_NumericalMethod=" |
- | Number_max_Grid = 5 , | + | |
- | Number_max_Cycle= 10 , | + | & |
- | Number_Iteration= 15, | + | |
- | Number_Iteration_FineToCoarseGrid= 5, | + | Number_max_Cycle= 10 , |
- | Number_Iteration_CoarsestGrid | + | Number_Iteration= 15, |
- | Number_Iteration_CoarseToFineGrid= 10, | + | Number_Iteration_FineToCoarseGrid= 5, |
- | Relaxation_Coefficient | + | Number_Iteration_CoarsestGrid |
- | Convergence_Criterion | + | Number_Iteration_CoarseToFineGrid= 10, |
- | | + | Relaxation_Coefficient |
+ | Convergence_Criterion | ||
+ | |||
+ | ==== Example 3 : An iterative method coupled with a multigrid procedure using the HYPRE library ==== | ||
+ | |||
+ | <WRAP info> | ||
+ | |||
+ | Suitable setting : | ||
+ | |||
+ | * Selection of the PFMG method using a SOR relaxation method for non symmetrical matrix (even though the Poisson' | ||
+ | * The number of iterations is : | ||
+ | * The maximum iteration number is 20 | ||
+ | * 5 relaxation sweeps before coarse-grid correction | ||
+ | * 10 relaxation sweeps after coarse-grid correction | ||
+ | * The tolerance convergence is 1E-08 | ||
+ | </ | ||
+ | |||
+ | === Using the namelists " | ||
+ | |||
+ | |||
+ | & | ||
+ | | ||
+ | TemperatureAdvection_Scheme=" | ||
+ | Poisson_NumericalMethod=" | ||
+ | |||
+ | & | ||
+ | Number_Iteration | ||
+ | Number_Iteration_FineToCoarseGrid= 5, | ||
+ | Number_Iteration_CoarseToFineGrid= 10, | ||
+ | | ||
+ | |||
+ | |||
+ | |
sunfluidh/numerical_methods_examples.1506348096.txt.gz · Dernière modification : 2017/09/25 16:01 de yann