# Tutorial 12: Topology Design for a Curved Test Section

## Tutorial 12. Topology design for a curved test section

#### Step 1. Load the Geometry

Load the tut_10.fra file into the graphic manager. Make sure that the surface files that this TIL file refers to are accessible by the graphic manager.

You should be able to see the surfaces as shown in the next page. As you can see, the geometry consists of two turbine blades in a curved test section. Study the geometry and understand it before you move on create the topology for this.

#### Step 2. Creating a simple topology

Note that this gepmetry is topological similar to a geometry.

#### Step 3. Splitting corners to avoid the singularity

Now, lets go back to the topology builder and see what the singularity is all about.

#### Step 4. Avoiding the six point singularity

You had made the first correction and improved the quality of the grid near the corners. But by splitting corners, you had added more connections to some points and as a result, they now have 6 blocks sorrounding them. This is a bad sungularity.

#### Step 4. Avoiding the six point singularity

You had made the first correction and improved the quality of the grid near the corners. But by splitting corners, you had added more connections to some points and as a result, they now have 6 blocks sorrounding them. This is a bad sungularity.

#### Step 6. Making the case three dimensional

Now, for the fun of it, we are going to make the case three dimensional. Making this case three dimensional is pretty simple. The first step is to go to the dim pull down menu and select dim=3. The next step is to create two planes parallel to the plane to bound the test section in the z direction. And then, simple copy the present topology with op back edges to the cut plane to get the complete three dimensional case.

#### Step 7. Compact enrichment

You are now ready to add internal surfaces to the enhance the grid at important points. Remember that the geometry is now a three dimensional one.