GAS PROPERTIES AT LOW PRESSURES

Gas transport properties are required to apply the theory given in Sections 3.3 and 3.4. Viscosities of pure nonpolar gases at low pressures are predicted from the Chapman-Enskog kinetic theory with a Lennard-Jones 12-6 potential. The collision integrals for viscosity and thermal conductivity with this potential are computed from the accurate curve-fits given by Neufeld et al. (1972). 

Lennard-Jones parameters for H2 at temperatures above 300 K are taken from Hirschfelder, Curtiss, and Bird (1954) as cr = 2.915A, e/n = 38.OK. Values for normal fluids are calculated from Correlation iii of Tee et al. (1966) 

Here is the fluid s critical pressure in atm, is the fluid s critical temperature in Kelvins, and u) is the fluid s acentric factor as defined in Poling et al. (2001). With these parameters, the kinetic theory reproduces the viscosities of the 14 investigated normal fluids with a RMS deviation of 2.13 percent. 

Thermal conductivities of pure nonpolar gases at low pressures are predicted by the method of Chung et al. as presented in Eqs. (10-3.14,15) of Poling et al. (2001), who report that this method except for polar compounds, yields values quite close to those reported experimentally. Viscosities of nonpolar gas mixtures at low pressures are calculated by the method of Wilke (1950) from the pure-component values at the same temperature and pressure, 

Thermal conductivities, km- of nonpolar gas mixtures at low pressures are calculated from a formula like Eq. (3.5-3), but with p replaced everywhere by k as in the book Transport Phenomena by Bird, Stewart, and Lightfoot 

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