[Stargazer]

Hi,

I am studying the best practice on external aerodynamics of vehicles given by Siemens. In this guideline, a1=1 under steady simulation, but what about the unsteady case if I use only SST k-w instead of DES? Is a1 can be still set as 1?

I realize that a1 can be tuned based upon experimental results, however what if the experimental data are unavailable, then what is the general suggestions under unsteady simulation? Thank you.

[f-w]

I only experimented with a1 in steady-state, but from a rational perspective, in the absence of experimental data, general suggestion would be to use the default value. Especially for a1, which significantly affects sensitivity to separation.

Results from this document (Figure 97), suggest that as well:
https://www.ansys.com/content/dam/am...nsys%20CFD.pdf

[Stargazer]

Originally Posted by f-w

I only experimented with a1 in steady-state, but from a rational perspective, in the absence of experimental data, general suggestion would be to use the default value. Especially for a1, which significantly affects sensitivity to separation.

Results from this document (Figure 97), suggest that as well:
https://www.ansys.com/content/dam/am...nsys%20CFD.pdf

Thanks for the suggestions. I am not sure how much could be the difference, for I use a1=1 in some unsteady simulations of some reports.