Is there a way to set the BCs for a one-way valve that exits to atmospheric pressures? It allows air to exit the system, but not enter it. The attached pdf shows the setup. I've read about using solid disks to close off the exit port, but we don't have the motion package to do that.
Is the outflow of the right boundary known? If yes, how about specifying that as a function of time and letting the left boundary take care of its own. But if you want to prescribe the left boundary definitively, and still want the right one as unidirectional, then can't think of any way...