This library project shows how fast users can set up fluid flow analyses with SimScale. The CAD model was provided by Tommi P. Laiho. For the mesh creation I used the automated hex-dominant operation for external flow. This operation has about 5 input parameters that are enough to create a virtual wind tunnel around the CAD model shown in the picture above. The picture below shows the automatically created wind tunnel mesh.
Especially the region behind the car body where significant separation effects can be expected would need to be more refined in order to resolve the phenomena in this region. This shows that the automated hex-dominant mesh operations are meant for first test or rough analyses. For more detailed analyses, the fully featured hex-dominant operation can be used. An example mesh with a finer mesh resolution behind the car body is shown in the picture below.
The analysis itself was set up using the steady-state incompressible fluid flow analysis type with a k-omega-SST model for the turbulence. The analysis was carried out on 4 cores and took around an hour. The picture below shows the pressure map on the car surface
The residual plots of this simulation show that the solution has not converged. For a fully converged solution, we might use a finer mesh and a longer compute time. However it might also be possible that this car body leads to transient phenomena which can not be resolved in such a steady state simulation. To answer these questions, we would have to dive deeper into this analysis – but the objective of this project is to show the quick setup of a virtual wind tunnel. The picture below shows a streamline visualization, post-processed locally with ParaView