Hybrid Mesh Movement
The CENTAUR mesh movement tool provides an important feature that allows the generation of derivative meshes for a geometry using an existing mesh. The advantage of hybrid mesh movement becomes clear when considering a geometry where the changes to the configuration are relatively small. These types of cases are typical of design optimization problems.
Mesh Movement Process:
Mesh Movement Benefits:
- Mesh generated for original configuration.
- Geometry changed to a new configuration.
- Original mesh is modified to conform to the new configuration.
- The connectivity of the mesh does not change:
- Solution for the original geometry can be used as a starting point for the new geometry
- All clustering in the original mesh will be present in the new mesh
- Mesh differences are less likely to be the cause of differences in the solution
- The mesh movement process requires significantly less time than a completely new mesh generation step.
- No additional setup time is required for new variations to the geometry.
Example: Straked Cylinder
The process is best demonstrated via a simple straked cylinder geometry. The first case is a cylinder strapped with a helical strake of rectangular profile. This geometry is then altered to have a trapezoidal strake profile and the mesh is "migrated" onto the new geometry.
Original Hybrid Mesh
The original hybrid grid is created with prisms grown from the surface of the cylinder and tetrahedra in the farfield. The first image shows a fieldcut of the mesh at the middle of the cylinder and the second image shows the mesh on the symmetry plane.
New Hybrid Mesh for Derivative Geometry
Next, the profile for the strakes is changed from a rectangular shape to a trapezoidal shape as shown below. The motion is not overly large, and it is restricted to the region immediately around the strake. The topology of the geometry has not been altered.
The resulting hybrid grid is shown below. The original mesh has been "migrated" onto the new geometry without any problems.