Zero Pressure Flat Plate CFD++
 

Hi, I'm trying to perform a trasient simulation of a subsonic flow over a
flat plate in CFD++.
I want to impose a ramp profile on the velocity at the inlet, like for
instance a smooth step, and look at the evolution of the boundary layer
over the plate due to this acceleration.
I want to perform this simulation without pressure gradient so I'm imposing
a back pressure value in outflow BC. The problem is that once I start the
acceleration at the inlet it creates a pressure gradient that travels to
the outlet, and since the pressure there is kept constant, the pressure
wave bounces creating instabilities
Does any one know how to perform this simulation without creating pressure
gradients?
Thanks