Différences

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

--- sunfluidh:sunfluidh_tools [2020/10/21 16:25] – [Staggered grid] yann
+++ sunfluidh:sunfluidh_tools [2020/10/27 15:47] (Version actuelle) – [Staggered grid] yann
@@ Ligne 23: / Ligne 23: @@
 ----
-The spatial discretization of equations is carried out on a cartesian staggered grid :
+The spatial discretization of equations is carried out on a staggered grid :
      * The velocity components are located at the cell-faces
      * The scalar quantities (temperature, pressure, density, ...) are located at the center of cells.
-{{ :sunfluidh:maillages_decales.jpg?direct&400 |}}
+{{ :sunfluidh:maillages_decales.jpg?direct&600 |}}
-     * Scalar quantities and velocity components are therefore their own coordinate set as this can be seen on this 2D configuration :
+     * Scalar quantities and velocity components are therefore their own coordinate set as this can be seen on this 2D sketch (same rules are adopted for a 3D configuration). Coordinate sets are defined from cell-centre coordinates {$x_c(i), y_c(j)$} and cell-face coordinates {$x_i(i), y_i(j)$}:
+           * for any scalar quantity like the pressure $P(i,j)$ : {$x_c(i),y_c(j)$}
+           * for the horizontal velocity component $U(i,j)$ : {$x_i(i),y_c(j)$}
+           * for the vertical velocity component $V(i,j)$ : {$x_c(i),y_i(j)$}
-{{ :sunfluidh:maillages_decales_volcontrol.jpg?direct&400 |}}
+{{ :sunfluidh:maillages_decales_volcontrol.jpg?direct&800 |}}
+----
+==== Ghost-cells ====
+----
+The code uses ghost-cells at the domain's ends in order to handle the boundary conditions. These ghost-cells are placed around the computational domain, which is plotted with red lines in the next figure.
+{{ :sunfluidh:dom-maillages-decalees.jpg?direct&600 |}}
+<note important>
+The grid size over the computational domain, which is set in the input data file, is enhanced by two in each direction (for example, a 2D grid size $64 \times 64$ over the computational domain becomes $66 \times 66$ in the code).
+</note>
 ----
 ==== Boundary conditions ====