Numerical simulation of real gas flows in natural gas supersonic separation processing

The real gas effects on natural gas supersonic separation were investigated using a computational fluid dynamics approach with ideal gas and real gas models. The computed results showed that the fluid properties calculated by the ideal gas law diverged significantly from the real gas cases in the supersonic zones, while the real gas models predicted a similar result from one to the other. The deviation of the gas Mach number between the ideal and real gas models was about 13.50% at the nozzle exit, while the error in the gas density was more than 20% in the whole supersonic separators. The shock wave position calculated by the real gas model was ahead of the one calculated by the ideal gas law. The shock position moved forward with the increasing inlet pressure, while the real gas predicted value was always in front of the ideal gas value. The relative error of the gas Mach number exceeded 15% with an inlet temperature of 283 K.