Curve Controls and Values

Use the curve controls and values to define the mesh controls that you want to modify.

You can modify several mesh controls with a curve control:

Controls - Minimum and Target Surface Size Properties

For the mesh controls that are listed, you can specify the properties as relative or absolute.

  • Minimum Surface Size
  • Target Surface Size
Control Custom

Allows you to specify a value for this control that overrides the default control.

Parent

Uses the same value as the default control.

Controls - Anisotropic Surface Size

Specify anisotropic surface size settings

Allows you to use anisotropic meshing when Meshing Method is set to Quad Dominant. Activating this property creates a set of sub-nodes which allows you to set anisotropic cell sizes on part curves. For more information, see Anisotropic Meshing for Lifting Surfaces.

Specify anisotropic mesh distribution between close Part Curves Activating this property creates a set of sub-nodes which allows you to specify the anisotropic mesh distribution between two part curves.

For example, you should activate this option to generate a good quality mesh at the blunt trailing edge of a wing.

Values - Anisotropic Surface Size

Growth Ratio Controls how fast the thickness of the layers increases and it is expressed as a ratio between adjacent layers. When the growth ratio is set to a low value, the transition between quadrilateral cells is very gradual. When a higher value is used, the transition is far more rapid.
Maximum Aspect Ratio Controls the maximum value to which the quad elements can stretch along the part curve. The available range is 3 to 10. The default value of 10 is recommended. Lower values allow you to fine tune the mesh sizing along the curve.
For the best quality mesh:
  • Ensure opposing anisotropic curves have similar settings.
  • Avoid having non-anisotropic curves next to anisotropic mesh controls.
  • Avoid a high number of anisotropic curves within a small area. This over-constrains the problem.

For certain applications, such as 3D Cell Designer, a high aspect ratio can speed up the anisotropic meshing process.
Number of Constant Layers

Controls the number of layers that are generated within the First Layer Thickness on a part curve. When anisotropic meshing is enabled on a curve, the surface remesher generates a number of face layers (n) of fixed size, normal to the curve. Starting from n+1, the anisotropic layers grows in size with a ratio equal to the growth ratio until the anisotropic size of the layers are the same as the isotropic size (target size) of the surface in that position.
First Layer Thickness

Sets the thickness of the layer growing normally from the part curve (typically the short distance in the streamwise direction).
Minimum Layer Size in Narrow Regions of Thin Areas

Allows you to specify the size of the layers in the thin area between two anisotropic part curves. This option is useful when you have two opposite part curves that meet together in a cusp. It allows you to use fewer than the Minimum Number of Layers when approaching the cusp.

The example below shows how to generate a good quality mesh in thin areas between two part curves. The first example (top image) shows an aligned mesh where the layers becomes thin as they approach the trailing edge. For this case, the Minimum Number of Layers is set to 3 and Minimum Layer Size in Narrow Regions of Thin Areas is set to a small value close to zero. The second example (bottom image) shows a low quality mesh where the layers decreases as they approach the trailing edge. In this example, the Minimum Number of Layers is set to 3 without specifying a Minimum Layer Size in Narrow Regions of Thin Areas value.

This option is an advanced parameter and should only be used in rare circumstances. When specifying a value, make sure that the value is less than or equal to the First Layer Thickness .

Minimum Number of Layers Specify the minimum number of layers that are generated between two anisotropic curves (thin area), for example in the blunt edge of a wing. This option should only be applied to thin areas and it is not recommended to use a large number of layers.

Controls - Wake Refinement Properties

The curve controls and values for wake refinement are the same as the surface controls and values for wake refinement. See Surface Controls And Values.