Hi,

I have a theoritical problem appeared after different simulations and I hope this is the right place to find help ... I simulate sloshing in a closed 3/4 filled tank undergoing movements and I observed that the amplitude of the waves is smaller when I increase the pressure of the void part of my tank. It seems ok with physic sense but I can not find how to explain it looking at the equations ! Where does it appears ? I work in laminar flow with viscosity. Thanks in advance for any clue you could give me ... it is driving me crazy !

Look at the conditions at the interface between gas and liquid. As the normal stresses are balanced by the curvature, the smaller pressure difference means smaller curvature, i.e. larger radius, smaller interfacial area, smaller amplitude...