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Viscosity calculation of supercritcal gases based on the modified Enskog theory
Yousef Ghayeb, Bijan Najafi, Vahid Moeini, Gholamabbas Parsafar

A new method, based on the modified Enskog theory, is presented for the calculation of viscosity of some supercritical fluids, including refrigerants R152a and HFC-125 at high temperatures and pressures. For this purpose, new correlation functions for the calculation of the thermal pressure coefficient and co-volume have been derived. The extended corresponding-states method has been applied to derive a universal function for the reduced thermal pressure coefficient of different gases and refrigerants. It is shown that by using these accurate values for the thermal pressure coefficient and co-volume in the modified Enskog theory, it is possible to calculate the viscosity of supercritical fluids and refrigerants, without any density and temperature limitation. The accuracy of the calculated viscosity is about 0.3%, which is much better than in previous works.

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