SimScale CAE Forum

Problems with yaw simulations

Good Day,

We are currently looking into running yaw simulations for our car model. In direct flow the simulation worked as expected and we are happy with the results.

The only change we have made between the direct flow, and yaw models, is that the wheels have been rotated. We have followed the same mesh procedure that worked in direct flow and unfortunately it does not seem to work.

The issues seen in simulations runs 1-6, suggest velocity divergence for the cause of failure. Typically, these occur around the wheels, suspension or small faces. Orginally i thought the cause may have been the rotating wheels, trying a simulations with this taken out was also no help.

I have tried, as best as i can, to target these issue with mesh refinements but every simulaiton a new velocity divergence issue seems to crop up at a different location

This issuse is slighty confusing, as mentioned earlier, we don’t believe the change in geometry is drastic enough to cause the issue.

Any help would be greatly appreciated.

I have a link to the project below, i have set this to public so hopefully it can be accessed.

Many thanks

https://www.simscale.com/projects/2a79252ca57a4a/yaw_17/

1 Like

Hi there :smiley:

Instead of having to rotate the wheels for each angle you wish to test, you can simply control the inlet velocity’s vectors:

https://www.simscale.com/workbench/?pid=1594826736729207029&mi=spec%3A9e37d6c8-a5ee-423b-8e2d-38265cf8f813%2Cservice%3ASIMULATION%2Cstrategy%3A1&ps=analysis%2FIncompressible--oneOf%2FboundaryConditions%2F0

In any case, you can locate the ‘bad’ cells that need refinement with the isovolume method described here:

Let me know what you think :slight_smile:

Bets regards,
Fillia

Thank you! I will give this a go :slight_smile:

1 Like

Hi, Just wondering how the second velocity is calculated? I can’t seem to figure out where they got 7.28 m/s from?

This is because of the angle of attack that is being tested: