[PLD]

Hi,

I have a problem using pimpleDyMFoam when simulating a pitching hydrofoil (pitching from 0° to 15°): the solution converges but the lift coefficient is lower than expected, up to 50% ! The expected values come from CFX AND experiments so I think they are reliable.
I use OpenFOAM 2.1.1 with the k-omega SST turbulence model. I have tried two different ways to obtain the pitching but both give bad results :
- deforming mesh (dynamicMotionSolverFvMesh)
- sliding mesh (AMI)
I have read in other threads that pimpleDyMFoam may be unstable for CFL higher than 2 so I chose an adaptive time step with CFL = 1 (I have also tested fixed time steps dt=10^-5 and dt=10^-4).
I have tested 3 different meshes (22k, 41k and 76k cells).
I have tested 2 different angular velocities (6°/s and 63°/s).
Results of all these different tests differ a little but none of them gives good results...

It is strange because calculations at fixed angles of attack with simpleFoam and pimpleFoam give very good results for both lift and drag coefficients.

Do you have an idea regarding this issue ? Does it come from the solver pimpleDyMFoam ?

Thanks in advance,
Best Regards,