Différences

Ci-dessous, les différences entre deux révisions de la page.

--- sunfluidh:hypredata_poissonsolver_namelist [2017/09/25 13:08] – créée yann
+++ sunfluidh:hypredata_poissonsolver_namelist [2017/09/27 16:32] (Version actuelle) – [SolverName] yann
@@ Ligne 8: / Ligne 8: @@
      * Poisson_NumericalMethod= Hypre-VariableMatrixCoef
    * The HYPRE library tools can be only used when the code is compiled with a MPI configuration.
+   * Even though numerical methods provided in the HYPRE library are similar to these ones present in the code, the input data are slightly different
    * __** Not for the release SUNFLUIDH_EDU**__
 </note>
@@ Ligne 15: / Ligne 16: @@
 ===== Full data set of the namelist =====
-   &HomeData_PoissonSolver  SolverName="SOR-Redblack-MPI",
+   &HypreData_PoissonSolver  SolverName= "PFMG" ,
-                            Number_max_Grid= 5,
+                             PreconditionerName= "NONE" ,
-                            Number_max_Cycle= 10,
+                             RelaxationMethodName= "SOR-RedBlack-Nonsym",
-                            Number_Iteration= 0,
+                             Convergence_Criterion = 1.D-08  ,
-                            Number_Iteration_FineToCoarseGrid= 1,
+                             Number_Iteration= 10 ,
-                            Number_Iteration_CoarseToFineGrid= 5,
+                             Number_Iteration_FineToCoarseGrid= 1,
-                            Number_Iteration_CoarsestGrid= 10 ,
+                             Number_Iteration_CoarseToFineGrid= 5 ,
-                            Relaxation_Coefficient= 1.7 ,
+                             Matrix_Symmetrization= .false. ,
-                            Convergence_Criterion= 1.D-15,
+                             Off_Set_Poisson_Source_term= .false. /
-                            Off_Set_Poisson_Source_term= .false. /
@@ Ligne 36: / Ligne 36: @@
 ==== SolverName ====
    * Type: Character string
-   * Selection of the iterative solver coupled with the multigrid method.
+   * Selection of numerical methods for solving the Poisson's equation( PFMG or SMG are recommanded).
-       * __JACOBI__           : Successive Over Relaxed solver based on the Jacobi's method
+       * __SMG__           : Parallel semicoarsening multigrid solver for the linear systems arising from finite difference, finite volume, or finite element discretizations of the diffusion equation. SMG is a particularly robust method. The algorithm semicoarsens in the z-direction and uses plane smoothing. The xy plane-solves are effected by one V-cycle of the 2D SMG algorithm, which semicoarsens in the y-direction and uses line smoothing.
-       * __SOR__              : Successive Over Relaxed solver based on the Gauss-Seidel method
+       * __PFMG__              : PFMG is a parallel semicoarsening multigrid solver similar to SMG. The main difference between the two methods is in the smoother: PFMG uses simple pointwise smoothing. As a result, PFMG is not as robust as SMG, but is much more efficient per V-cycle.
-       * __SOR-Redblack__     : Successive Over Relaxed solver based on a "Red-Black" algorithm (useful with OpenMP-parallel computations)
+==== SolverName ====
-       * __SOR-Redblack-MPI__ : Successive Over Relaxed solver based on a "Red-Black" algorithm optimized for the domain decomposition approach (MPI-parallel computations)
+   * Type: Character string
+   * Selection of a preconditioner. Not useful for SMG or PFMG methods.
-==== Number_max_Grid (multigrid method only) ====
+     * __NONE__ : No preconditioner is considered.
-   * Type : Integer value
+     * __SMG__  : The SMG method is used as preconditioner.
-   * Maximum number of grid levels used in the multigrid method.
+     * __PFMG__  : The PFMG method is used as preconditioner.
-==== Number_max_Cycle (multigrid method only) ====
-   * Type : Integer value
+==== RelaxationMethodName (for PFMG method only) ====
-   * Maximum number of V-cycles permitted in the multigrid method.
+   * Type : Character string
+   * Set the solver for the relaxation procedure
+       * __Jacobi__ : Jacobi's method
+       * __Weighted-Jacobi__ : Weighted Jacobi's method
+       * __SOR-Redblack-sym__ : SOR method for symmetrical matrix
+       * __SOR-Redblack-Nonsym__ : SOR method for non symmetrical matrix
+       *
 ==== Number_Iteration (only if the SOR method is used) ====
    * Type : integer value
-   * Number of iterations performed by the SOR method in order to approach the solution on each grid level. This value is the same for any grid level of the Multigrid procedure.
+   * Maximum number of iterations performed by the SMG or PFMG method
-==== Number_Iteration_FineToCoarseGrid (only if the SOR method is used) ====
+==== Number_Iteration_FineToCoarseGrid (only if the PFMG method is used) ====
-   * Type : integer value
-   * Number of iterations performed by the SOR solver during the restriction step of each V-cycle of the multigrid procedure. For some problems, the minimization of iterations during the restriction step can improve the time-performance of the code.\\ __BEWARE__ : this data is enabled only if the variable Number_Iteration= 0 or is removed from the Namelist.
-==== Number_Iteration_CoarsestGrid (only if the SOR method is used) ====
    * Type : integer value
-   * Number of iterations performed by the SOR solver on the coarsest grid of each V-cycle of the multigrid procedure.\\ __BEWARE__ : this data is enabled only if the variable Number_Iteration= 0 or is removed from the Namelist.
+   * Number of relaxation sweeps before coarse-grid correction
-==== Number_Iteration_CoarseToFineFGrid (only if the SOR method is used) ====
+==== Number_Iteration_CoarseToFineFGrid (only if the PFMG method is used) ====
    * Type : integer value
-   * Number of iterations performed by the SOR solver during the prolongation step of each V-cycle of the multigrid procedure.\\ __BEWARE__ : this data is enabled only if the variable Number_Iteration= 0 or is removed from the Namelist.
+   * Number of relaxation sweeps after coarse-grid correction
 ==== Relaxation_Coefficient (only if the SOR method is used) ====
    * Type : real value between one and two
@@ Ligne 65: / Ligne 69: @@
 ==== Convergence_Criterion (only if the SOR method is used) ====
    * Type : real value
-   * The nV-cycle procedure of the multigrid method is stopped if the L2-norm of the Poisson equation's residu is lower than the criterion chosen.
+   * the computation is stopped if the residu is lower than the criterion chosen.
+==== Matrix_Symmetrization ====
+    * Type Boolean value (default value= .false.). __** Not for the release SUNFLUIDH_EDU**__.
+    * The matrix is symmetric (set to .false. if any doubt exits)
 ==== Off_Set_Poisson_Source_term ====
-   * Type : Boolean value. __** Not for the release SUNFLUIDH_EDU**__.
+   * Type : Boolean value (default value= .false.). __** Not for the release SUNFLUIDH_EDU**__.
    * The source term is shifted from its averaged value such as its integral value over the domain is zero. This could facilitate the convergence in some particuliar cases. this option must be used with caution. For expert users only.