[oschi]

Hello,
I have searched for boundary conditions which let me define that there is zero (or another, prescribed) mass flux across certain boundary faces.

However, fixedValue U=(0,0,0) or inletFlowVelocity (massFlowRate=0) operate on absolute velocities on the fixed coordinate system, so that the relative velocities on a moving boundary are anything but zero.

Is it possible to modify the fixedValue, inletFlowVelocity, noslip or other boundary conditions such that the relative velocity ("U-meshU") is solved to the given value?

I am using the rhoPimpleDyMFoam solver with a boundary that is deforming as result from external forces, if that matters. So, the boundary position and motion is already known at every time.

Greetings
Olaf