Wake Refinement

Wake refinement using the Parts-Based meshing approach allows you to define the direction, distance, and spread angle of the wake relative to a part surface or part curve from which the wake grows.

The wake grows from the part surface or part curve into the fluid volume of the wake which is then refined to the parameters that you specify. Setting a large growth rate means that the cell size increases rapidly from the part surface or part curve into the wake. The cells within the wake stop growing when the cell size reaches the specified maximum cell size within the wake. Using a large part surface to grow a wake from can cause excessive cell counts in the fluid volume. It is computationally less expensive to use part curves which define a specific feature instead of a large part surface. When you intend to view a scalar output in 3D in the wake, use a part surface. However, if you only intend to view a scalar output on a plane propagating downstream, you can use part curves at the trailing edge for wake refinement.

The main advantage in using the wake refinement option rather than a volumetric control is that you define the refinement zone with a surface. Therefore, if the boundary surface changes, the wake refinement changes also. This characteristic is useful in parametric or batch studies where the same settings are applied to several geometries.

You can perform wake refinement using an Automated Mesh Operation with any of the following meshers:
  • Surface Remesher
  • Polyhedral Mesher
  • Tetrahedral Mesher
  • Trimmed Cell Mesher
NoteYou can also use the Prism Layer Mesher with a core mesher, although, it is not possible to specify wake refinement settings for the Prism Layer Mesher.
Before refining the mesh in a wake, make sure that the starting geometry represents the fluid that surrounds the object which causes the wake.
  1. Right-click the Geometry > Operations node and select New > Automated Mesh Operation.
  2. In the Create Automated Mesh Operation dialog:
    1. Set Parts to the part which represents the fluid volume.
    2. Select the meshers that you require for meshing the fluid volume.
    3. Click OK.
  3. Expand the Automated Mesh > Default Controls node and set the parameters that you require for the overall fluid domain.
  4. Right-click the Automated Mesh > Custom Controls node and select New > Surface Control or New > Curve Control.
    To avoid confusion, you can rename the Surface Control or Curve Control node to represent the Wake Refinement.
  5. Select the Surface Control or Curve Control node and in the Properties window:
    1. Ensure that Enable Control is activated.
    2. Specify the Part Surfaces or Part Curves from which the wake refinement should grow.
  6. Define the Part Surfaces or Part Curves custom controls. Either:
    • Expand the Custom Controls > Surface Control > Controls node, then specify the Surface Controls for the Part Surface that is selected and the wake. See Surface Controls And Values.
    • Expand the Custom Controls > Curve Control > Controls node, then specify the Curve Controls for the Part Curve that is selected and the wake. See Curve Controls And Values.
    NoteThe quality of the surface mesh affects the quality of the wake directly.
When refining the mesh settings, make sure that you set the controls and values correctly in the area that you intend. The following example shows the wake from a car and the location in the simulation tree where you can refine each area. A surface control is set for the car surface and the wake occurs within the polyhedral volume mesh in a specified direction up to a specified angle and distance from the car surface.




  1. Execute the Automated Mesh Operation.
  2. If necessary, modify the mesh settings and re-execute the Automated Mesh Operation.
    NoteIf the cell size within the wake refinement grows too quickly to the specified maximum cell size, you can increase the maximum cell size that is specified for the wake, or you can decrease the growth rate.
  3. To turn off wake refinement temporarily without losing any settings that are already defined, you can either:
    • Deactivate all Surface Control or Curve Control settings and the wake refinement by selecting the Custom Controls > Surface Control or Custom Controls > Curve Control node and deactivating Enable Control.
    • If you want to maintain all Surface Control or Curve Control settings except the wake refinement, select the Custom Controls > Surface Control > Wake Refinement node or the Custom Controls > Curve Control > Wake Refinement node and deactivate Specify wake refinement options.