Hybrid Mesh Movement
The CENTAUR mesh movement tool provides an important feature that allows the generation of derivative meshes for an existing geometry. It is applicable to design optimization problems as the mesh generated for the initial geometry deforms to follow the re-designs.
Example: Straked Cylinder
The reshape process is demonstrated via a simple straked cylinder geometry. A cylinder strapped with a helical strake of rectangular profile is altered to have a trapezoidal strake profile and the mesh is “migrated” onto the new geometry.
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.
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.
Example: Turbine Blade Twist
A straight turbine blade is twisted by five degrees in the tip region. The mesh follows the geometric change.
Example: Turbine Blade Tip Clearance
This example shows the variations of the tip clearance for a turbine blade. The tip clearance is reduced by 50% and the mesh automatically adjusts to the new clearance.