Contracting the Basic Mesh

To do this, you need to set control planes surrounding the region and assign the proper Ratio values to the respective intervals. The cell sizes on the interval are changed gradually so that the proportion between the first and the last cells of the interval is close (but not necessarily equal) to the entered Ratio value. Negative values of the ratio correspond to the reverse order of cell size increase. Alternatively, you may explicitly set the Number of cells (Ncell) for each interval (Ii), in which case the Ratio value (R) becomes mandatory. For example, assume that there are two control planes Plane 1 and Plane 2 (see Figure 1) and the ratio on the interval between them is set to 2. Then the basic mesh cells adjacent to the Plane 1 will be approximately two times longer than the basic mesh cells adjacent to the Plane 2.

Use of control planes is especially recommended for external analyses, where the computational domain may be substantially larger than the model.

In the Table 1 (b) two custom control planes are set around the body in each coordinate direction with the ratio set to 5 and –5, respectively.