Description

For Gmsh export, the Set Solver Attributes panel provides a number of settings to control the polynomial degree of the exported mesh.

CAE, Solver Attributes, Gmsh
The polynomial degree can be specified for Gmsh solver export.

The settings in the Set Solver Attributes panel for Gmsh are used to set up elevation of the polynomial degree of the exported grid:

 

Note: High-order polynomial elevation is only available for 3D grids.

  • Convergence Cost Threshold: Sets a maximum threshold value for the minimum curving cost function and stops the smoothing routine prior to reaching the specified number of smoothing passes if this maximum is reached. Convergence Cost Threshold varies from 0.0 to 1.0 and defaults to 0.8.
  • Max Included Angle: Sets the angle to determine which cells in the mesh will receive smoothing prior to elevation. Max Included Angle varies from 0.0 to 180.0 and defaults to 175.0 degrees. An entry of 180.0 turns off smoothing prior to elevation.
  • Polynomial Degree: Sets the polynomial degree for grid elevation. The default is Q1 or first degree. The mesh can be elevated to Q2, Q3, or Q4.
  • Step Size Relaxation Factor: Sets the step size to be used when iteratively smoothing the high-order nodes. Step Size Relaxation Factor varies from 0.0 to 0.5 and defaults to 0.05.
  • WCNSmoothing Passes: Sets the number of iterations or steps of the WCN Smoothing routine that will be run for each smoothing pass. WCNSmoothing Passes can be an integer between 0 and 10000 and defaults to 1000.
  • WCNWeighting Factor: Sets a weighting factor which determines the amount that the minimum curving cost function influences the WCN component. The normalized Jacobian value will be calculated as 1 - WCNWeighting Factor. WCNWeighting Factor varies from 0.0 to 1.0 and defaults to 0.5.
  • WCNWeighting Factor Mode: Sets whether WCNWeighting Factor is calculated (Calculate) or used directly as the value input (UseValue) and described above. WCNWeighting Factor Mode defaults to Calculate.
  • Write HOVTU: If set to true, then a high-order VTK Unstructured (VTU) grid file is exported in addition to Gmsh files. This VTU file can be used with ParaView to visualize P3 and P4 elements. Write HOVTU defaults to false.

Demonstration

High-Order Mesh Setup

High-Order Mesh Export