[alimea]

Hi all

I want to simulate the viscoelastic fluid flow in a curved duct at the creeping flow regime using rheoFoam solver. I solved this problem in the inertial regime and got good convergence, physical results, and short run-time in both low and high Weissenberg numbers. But the problem is very sensitive to the time-step and grid and has a long runtime in the high Wi case (Wi = 2) of creeping flow regime (There is no problem in Wi < 0.1). Also, when I plotted the pressure at a special point (to check the convergence), I faced some fluctuations. In addition, there are some strange structures in the streamlines (I think these are unphysical).

Is it normal for a creeping flow regime? Or related to the viscoelastic fluids? or related to my setup and solver?
How can I reduce the run time, and get stable physical results (without fluctuations)?

Thank you