Odd CFD Results

Project Support
1

Hello, I am an f1 student trying to test the drag on my car so I can improve its aerodynamics, but the numbers don’t seem right. The test was set up as I always have done but the chart is all over the shop and doesn’t make sense.

Graph??
Graph??2182×1266 175 KB

Thank you Bill

2

Hi Bill, thank you for sharing!

The case here is not converged. I have a couple of suggestions:

  1. Simulate half the model, and use the Standard mesher. You can use this tutorial as a reference.

  2. Make sure to calculate the width of the first cell on the walls appropriately, using this guide: How to Control and Analyze Y+ in Meshing Simulation | SimScale

  3. Toggle on the ‘Potential Flow initialization’ on the Simulation tab prior to the run.

  4. For this type of simulation, it would be best to have at least 1000 loops performed (this is the “End time” on the simulation control panel)

simulation control

  1. Check the convergence plot too to see whether the solution is stabilized is also advised: How to Check Convergence of a CFD Simulation? | SimScale

Best regards,
Fillia