Viscosity correlations of normal gases at normal pressures and several HFC refrigerants using the corresponding states theory

Coupling the corresponding states theory with the dimensional analysis method, the viscosity correlations for calculating gas-phase viscosity at normal pressures were proposed by correlating the non-dimensional viscosity η* with the reduced temperature T_r and the critical compressibility factor Z_C. The correlations would apply to monatomic gases, diatomic gases, hydrocarbons and halogenated hydrocarbons. Compared the calculated results with literature data, the absolute average of relative deviations (AADs) of the correlations are 0.47% for monatomic gases, 0.57% for diatomic gases, 0.37% for hydrocarbons and 0.43% for halogenated hydrocarbons, respectively.Meanwhile, the viscosity correlations of five halogenated hydrocarbons R32, R125, R134a, R143a and R152a were presented. The correlations were established by correlating the reduced residual viscosity Δη_r and the reduced density ρ_r on the base of the corresponding states theory. Compared the calculated results with literature data, the AADs of the correlations are 2.16%, 2.39%, 1.10%, 1.41% and 1.38%, respectively.