[fuhrmanj]

I try to implement a 2d steady state, incompressible channel flow with cyclic boundary conditions. The walls are "noSlip" and the inlet and outlet should have periodic boundary conditions (i.e. what flows out of outlet flows in at inlet). The flow should be driven by a "meanVelocityForce" which I implemented in "fvOptions". I am using simpleFoam with all turbulent properties turned off (the plan is to turn them on later, but for now I want to keep it simple). My mesh is generated using blockMesh. I am using two connected blocks because I want to be able to change the geometry of the second block later on to test its impact on the flow in the first block. Checking the mesh with "checkMesh" reports "Ok". I am using simpleFoam. The calculation converges at time=353. The case files are attached. You can execute it via blockMesh -> topoSet -> simpleFoam. I have also attached a picture of the velocity profile.

Here is my question: The picture shows, that the velocity slowly fades/vanishes towards the outlet. Since the inlet-outlet boundary conditions are cyclic and the flow is incompressible, I would expect that the cross-section averaged velocity is conserved, i.e. no fading. I would also expect the velocity profile to be somewhat continuous with no jump. This is clearly not the case. What do you think I am missing? Thank yo so much for your help!