PREDICTION OF THE TRANSPORT PROPERTIES OF SF₆ WITH O₂, CO₂, CF₄, N₂ AND CH₄ MIXTURES AT LOW DENSITY BY THE INVERSION METHOD (PART II)

Abstract

Viscosity and diffusion coefficients for five equimolar binary gas mixtures of SF 6 with O 2, CO 2, CF 4, N 2 and CH 4 gases are determined from the extended principle of corresponding states of viscosity by the inversion technique. The Lennard–Jones 12-6 (LJ 12-6) potential energy function is used as the initial model potential required by the technique. The obtained interaction potential energies from the inversion procedure reproduce viscosity within 1% and diffusion coefficients within 5%.

Determination of a potential energy function for nitrogen trifluoride by inversion of the new reduced viscosity collision integrals at zero density

“…The direct inversion of the viscosity collision integral correlation obtained from a correlated formula of viscosity is obviously an outstanding method for establishing a precise pair-potential energy [7][8][9][10][11][12][13][14][15]. So far, we are unable to find any correlation relation for viscosity collision integrals in the literature as we presented especially in the common ECS.…”

“…The transport properties were calculated using Monchick-Mason approximation (MMA) [23] which provided a simple scheme whereby the collision integrals may be calculated. The details of the principal assumptions made in their approach are given elsewhere [10,11].…”

“…Of particular interest is the development of an inversion technique for bulk properties [5][6][7][8][9][10][11][12][13][14][15], which are readily available for a wide variety of substances. The inversion scheme is an important method for generating the intermolecular potentials from the bulk properties and their ESC correlation [26].…”

“…As mentioned in our previous works [7][8][9][10][11][12][13][14][15] the ultimate purpose of the kinetic theory is to relate the macroscopic properties of the individual molecules to their interaction potentials. Typically, the first improvement on the Enskog dense-gas theory lies in neglecting the binary collision hypothesis.…”

“…For the noble gases, which have spherically symmetric interactions, inversion of transport properties data is directly related to the pair interaction potential u(r). For near-spherical and non-spherical molecules [7][8][9][10][11][12][13][14][15] inversion of transport properties gives an effective spherical potential u eff (r) related to, but different from, the true pair-potential u(r, x) which depends on the intermolecular orientation, x. These effective potentials are determined and widely used in both statistical mechanics [16,17] and chemical engineering calculations [18][19][20].…”