Bottom Up Hexa Mesh Strategy for a Grid Fin

In this tutorial, you will generate a hexa mesh for a Grid Fin. This could be done with top down methods, as is done in other tutorials. For example, the triangles between the fins could be handled with the option to create Y-blocks, or by creating an Ogrid and then collapsing the corners. However, the point of this tutorial is to introduce bottom up blocking concepts that will be helpful on very difficult examples. Further, since the geometry does not change significantly in the Z-direction, the 3D blocking is created by extruding an initial 2D blocking. This is simpler than building a bottom up 3D blocking (you do not need to select as many vertex locations), but the concept is the same.

Also, the Grid Fin is part of a rotating machine. You will minimize the model size by modelling only a section of the rotating machinery, and then implementing symmetry with Periodic nodes.

The geometry is as shown in Figure 139: Grid Fin Geometry

Figure 139: Grid Fin Geometry

This tutorial demonstrates how to do the following:

Create an initial 2D block associated with a minor geometry.
Create an Ogrid to extend the 2D blocking.
Complete the 2D blocking using vertex placement.
Extrude the blocking to 3D, and then create further splits and associations.
Resolve zero thickness walls.
Define periodicity.
Generate and refine the mesh.