Pressure distribution in an open cavity at linear increasing external pressure

A method is described for calculating the pressure profile in a cavity, connected by an opening with an environment in which the pressure is increasing linearly. The following conditions were assumed: constant volume, no gas sources inside the cavity, the same gases inside and outside the cavity and equal pressures at the start. Calculations were performed for both the adiabatic and isothermal changes of state, taking into account in first approximation the gas friction inside the opening. The solutions depend on two parameters. All necessary functions are given in the form of diagrams. The measured pressure functions obtained for an approximately 3 liter vessel are compared with theoretical results.