Critical Flow, One Phase (Component)

The mass efflux associated with an ideal, perfect gas moving through a choke point is derived from six conditions/assumptions and equations for the first and second laws of thermodynamics; this model is then extended to a van der Waal gas. The last section demonstrates that often a liquid phase develops as the gas is depressurized and shows the possible errors of ignoring the development of this liquid phase for a fluid that is initially a pure gas.