I have done an unsteady problem of a blade moving in a fluid with the moving mesh. I have also done it with MRF in steady state.

After a while, the unsteady problem with the moving mesh gives the same velocity profiles as with MRF in steady state.

1)Is it normal (I am sorry, but I don't understand very much the explanations of the users' guide)? Can I consider the MRF as the calculation is very shorter?

I also did in steady state with Moving mesh, but the results aren't the same. 2)Why? Whtt's the difference with MRF?

Thanks a lot for your answers

Hi,

if your problem is to model a single blade moving in the fluid then it is the same thing than having a fixed blade in a rotating air.

So it is absolutly normal that you have the same results with moving mesh, MRF and a single rotating frame of reference. A single rotating frame would be sufficient to solve your problem and it is also the correct approach.

On the other hand you can't do steady state calculation with moving mesh : it an intrisic unsteady model.

Best regards