Options for Grid

The hybrid mesh consists of the overlapped structured and unstructured meshes. The visualization options for the hybrid mesh is documented in this section.

Options for Grid dialog for controlling of the mesh visualization 

Figure 4.  Options for Grid dialog for controlling of the mesh visualization

Category

parameter

Show grid used for actual variable

The transport equations are solved and the field variables are calculated either on the unstructured or on the overlapped structured mesh, provided both types of the mesh are available. The kind of the used mesh depends on the transport equation.

Switching the option "Show grid used for actual variable" chooses the kind of the mesh for visualization automatically in dependence of the transport equation corresponding to the selected variable group. The variable group is selected in the top of the main CrysMAS window.

Show only unstructured grid

This indicates only unstructured mesh everywhere. The structured mesh, if available, will be hidden.

Show only structured grid

This indicates vice versa only structured mesh everywhere if available, the unstructured mesh will be hidden.

Show bad Grid

This option can be useful for diagnostic of the structured mesh quality. The activation of the option causes the colorization of the structured mesh cells with too large deviation from the orthogonality condition. The threshold orthogonality deviation is given by the next GUI parameter.

critical non-orthogonality [Deg]:

Deviation from the orthogonality in degrees for two systems of mesh lines within the structured mesh block. The default angle value about 30 degrees corresponds to occurrence of angles 90-30=60d degrees and 90+30=30 degrees in the structured mesh.

Usually the fluid mechanics and turbulence computation on the structured mesh runs without any mesh related problems if the critical deviation from orthogonality of 30 degrees is not exceeded. The deviation about 45 degrees may be critical for stability of the computations. Additionally a bad orthogonality increases the required number of iterations and the computational time.

Angles between the lines of the structured mesh at the inner block boundary have the same impact on the stability and computational time as the angles between the inner lines inside of the block. Note that these angles are not indicated by means of this dialog. Therefore additional care should be taken for the smooth mesh transitions at inner block boundaries.