Verification & Validation

Verification

Adapt the Mesh

In order to test our simulation for convergence, we will refine the mesh. However, instead of refining the mesh everywhere (which would be wasteful, as most of the area of the domain far away from the shock has constant values), we will use our results to refine our mesh. Specifically, we are going to use the gradient of the pressure to determine where to refine the mesh. First, let's take a look at our mesh. In the Outline window, select Graphics and Animations, under _Graphics, select Mesh, then press Setup. Select all of the surfaces (except y=0.35) and press Display. This will display the current mesh.

You may now close the Mesh Display window. In the menu bar, go to Adapt > Gradient. Under Options uncheck Coarsen. Ensure that Gradients of > Pressure... Static Pressure are selected. Then press Compute.

This will compute the maximum and minimum gradients of static pressure. Next, we need to pick a threshold. For every element that has a pressure above that threshold, that element will be refined. Let's make our threshold 10000. Enter 10000 into Refine Threshold. Then press Adapt. You will be asked if you want to change the mesh. Press Yes.

It will seem like nothing has changed, but that is because we need to re-display the mesh in order to see the adaption. The new mesh should look something like this.