You must specify the pressure at the cavity surface as a boundary condition of the simulation. Prescribing a pressure in the cavity is equivalent to applying a uniform pressure to the cavity boundary using a distributed load. When you prescribe a pressure using the cavity pressure feature, the fluid volume adjusts automatically to fill the cavity. In other words, you can assume that the fluid enters and leaves the cavity, as required, to maintain the prescribed pressure. This behavior is useful in situations where a load deforms the cavity before the introduction of the effect of the fluid. | |||||||||