[t.m]

Hi,

I am quite new to OpenFOAM and am currently working on the simulation of a tube oscillating at a high frequency (see picture).


I've tried both an open tube with a constant internal flow and a closed one without any internal flow at all. The case is solved using pimpleDyMFoam with angular oscillating displacement. The boundary conditions of the walls are set as movingWallVelocity (0 0 0) for U, respectively as zeroGradient for p (the case with inflow uses different conditions for the inlet and outlet).
The simulation itself appears to converge just fine, the final velocity and pressure fields, however, keep showing strange results at the walls (the errors in the middle are likely created due to the grid transition in the corners of the central square; see picture).

(Fullsize: https://imageshack.us/a/img577/4117/u020.png)

(Fullsize: https://imageshack.us/a/img442/5807/p020.png)

Has anyone experienced similar problems? Are maybe even the boundary conditions (especially the one for the pressure) wrong, as there actually should be some gradient due to inertia?

Thank you in advance,
Tobias