Coarsen Grid

The Coarsen Grid option is the opposite way to the Refine Grid option in that it decreases the resolution of the grid. It operates independently by dividing the existing number of cells in the current grid in I, J directions. There are three types of coarsening grid, global, by segment, and by block as described below:

(1) Coarsen grid globally

1. LMC on the grid layer in the Layer Control to select the grid to coarsen
2. Select Coarsen Grid option from the Grid menu, or click the Coarsen Grid button from the main toolbar (Figure 1).
3. The Grid Block Coarsening form will be displayed, as shown in Figure 1. Enter the Coarsening Factor then click the OK button. The default value for factors is 2. Figure 2 shows an example of grid refinement.

Figure 1 Coarsen grid.

Figure 2 Grid after Coarsening.

(2) Coarsen grid with a selected grid segment

1. LMC on the grid layer in the Layer Control to select the grid to coarsen
2. Select the Select object button from the main toolbar
3. LMC on a grid node then hold Shift key. LMC on the second node on same grid segment in I or J direction, and the segment will be highlighted as shown in Figure 3.
4. From Grid menu, select Coarsen Grid option (or select the Coarsen Grid button from the main toolbar), the Grid Block Coarsening form will be displayed as shown in Figure 4. Enter the Coarsening Factor then click the OK button. Figure 5 shows an example of grid coarsening for a selected grid segment.

Figure 3 Select a grid segment to highlight.

Figure 4 Grid Block Coarsening form.

Figure 5 An example of coarsening grid with a selected grid segment.

(3) Coarsen grid with a selected grid block

1. LMC on the grid layer in the Layer Control to select grid to coarsen
2. Select the Select object button from the main toolbar
3. LMC on a grid node then hold the Shift key. LMC a second node which is not on the same grid segment in I or J direction. The grid block will be highlighted as shown in Figure 6.
4. From Grid menu, select Coarsen Grid option (or select Coarsen Grid button from the main toolbar), the Grid Block Coarsening form will be displayed as shown in Figure 7. The user needs to enter the Coarsening Factor then click the OK button. Figure 8 shows examples for grid coarsening with a selected grid block.

Figure 6 Select a grid block to highlight.

Figure 7 Grid Block Coarsening form.

Figure 8 An example of coarsening grid with a selected grid block.