Différences

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

--- sunfluidh:numerical_methods_setup_namelist [2016/11/28 22:43] – yann
+++ sunfluidh:numerical_methods_setup_namelist [2017/09/25 14:28] (Version actuelle) – [Number_Iteration_CoarseToFineFGrid (only if the SOR method is used)] yann
@@ Ligne 1: / Ligne 1: @@
-===== Namelist "Numerical_Methods" =====
+===== Namelist "Numerical_Methods" (old version) =====
 <WRAP info>
-This data setup is devoted to the selection of the numerical methods and schemes used in order to solve the conservation equations for velocity components, temperature, species mass fractions and density (in particuliar cases) and Poisson equation for the pressure. Some parameter setting could be also considered in respect with the numerical method selected.
+This data setup is devoted to the selection of the numerical methods and schemes used in order to solve the conservation equations for velocity components, temperature, species mass fractions and density (in particuliar cases) and Poisson equation for the pressure. Some parameter setting could be also considered in respect with the numerical method selected. The data are divided in three groups in order to define :
+    * the numerical method applied for solving the conservation equations (for velocity, temperature, species, ...)
+    * the choice of advective or convective flux discretization (for 2nd order schemes). the viscous, conductive or diffusive fluxes are always discretized with a centered 2nd order or 4th order scheme according to the previous choice.
+    * the numerical method (and associated parameters) for solving the Poisson's equation according to the type of problem considered. several methods are presented based on direct or iterative approaches.
 </WRAP>
+<note important>
+   * Two versions of this data setup exists. This one is related to an old release of the code that can always be used. The second one is presented for in the namelist [[New_Numerical_Methods_Setup_Namelist |Numerical_Methods (new version)]].
+   * The choice of numerical methods is here done by means of a set of option numbers
+   * The parameters related to iterative solvers can be directly included in this namelist
+</note>
@@ Ligne 18: / Ligne 27: @@
                        Number_max_Cycle= 10                      ,
                        Number_Iteration= 15,
-                       Matrix_Symmetrization               = .false. ,
+                       Number_Iteration_FineToCoarseGrid= 15,
+                       Number_Iteration_CoarsestGrid= 15,
+                       Number_Iteration_CoarseToFineGrid= 15,
                        Relaxation_Coefficient              = 1.80 ,
                        Convergence_Criterion = 1.D-08 /
 <note important>
-Following the problem treated, some numerical methods are better adapted than others, this point is precised for each available option.
+   * Following the problem treated, some numerical methods are better adapted than others, this point is precised for each available option.
+   * The partial diagonalization method (Iterative_Method_Selection=3) used for solving the Poisson equation is only permitted for separable problem.
+   * When the partial diagonalization method is used, the data related to the SOR and multigrid method are useless and can be removed.
 </note>
 ===== Definition of the data set =====
@@ Ligne 51: / Ligne 64: @@
      * 2 : 2nd order centered scheme in the advective formulation.
      * 3 : 2nd order centered scheme in the skew-symemetric formulation (developer's test).
-     * 4 : not commented (develper's test)
+     * 4 : not commented (developer's test)
      * 5 : QUICK scheme in the conservative formulation.\\ __** Not for the release SUNFLUIDH_EDU**__ .
      * 6 : 2nd order Upwind scheme in the conservative formulation.\\ __** Not for the release SUNFLUIDH_EDU**__ .
@@ Ligne 63: / Ligne 76: @@
 ==== Explicit_Solving_of_Density ====
    * Type : integer value. __** Not for the release SUNFLUIDH_EDU**__ .
-   * Selection of the numerical method for solving the density. Some of proposed methods are "experimental" and they must be used with caution. The options are :
+   * Selection of numerical schemes based on flux limiters with TVD properties for solving the density. Some of proposed methods are "experimental" and they must be used with caution. The options are :
      * 0 : The mass equation is not solved. For low Mach number flows, the density is deduced from the equation of state. This supposes that species mass fractions or/and temperature are calculated from their conservation equations if it is required.
       * 1, 2, 4, 5 : Obsolete methods
@@ Ligne 73: / Ligne 86: @@
       * 10 : The mass equation is solved with the Lax-Wendroff + a TVD scheme defined by the user (test).
       * 11 : The mass equation is solved with a WENO5 scheme (test).
-      * 12 : Special option for the simulation of two-phase incompressible flows with a level-set method (distance function is solved with weno5 scheme). This option is available if the variables of the namelist "Fluid_Properties" :
-        * Incomp_Multifluids= .true.
-        * Variable_Density= .true.
 -----
@@ Ligne 88: / Ligne 98: @@
      * 3: Partial diagonalisation of the Laplacian operator. BEWARE : the problem must be separable.\\ __** Not for the release SUNFLUIDH_EDU**__
      * 4 : SOR iterative method coupled with a multigrid method in order to accelerate the convergence. The matrix elements depend on the cell size and the density, the source term is defined from the divergence of the velocity.\\ __** Not for the release SUNFLUIDH_EDU**__
-     *
+     * 5 : Poisson's equation is solved by the HYPRE library tools. The matrix elements are constants. The parameters of the HYPRE library are set in the namelist [[ | ]]
 ==== Iterative_Method_Selection (only if the SOR method is used) ====
    * Type : Integer value
@@ Ligne 104: / Ligne 114: @@
    * Type : integer value
    * Number of iterations performed by the SOR method in order to approach the solution on each grid level.
+==== Number_Iteration_FineToCoarseGrid (only if the SOR 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_Iteration_CoarseToFineGrid (only if the SOR 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.
 ==== Relaxation_Coefficient (only if the SOR method is used) ====
    * Type : real value between one and two