Isomorphic Viscosity Equation of State for Binary Fluid Mixtures

Abstract

The thermodynamic behavior of the simple binary mixtures in the vicinity of critical line has a universal character and can be mapped from pure components using the isomorphism hypothesis. Consequently, based upon the principle of isomorphism, critical phenomena and similarity between P -ρ -T and T -η -(viscosity) -P relationships, the viscosity model has been developed adopting two cubic, Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR), equations of state (EsoS) for predicting the viscosity of the binary mixtures. This procedure has been applied to the methane-butane mixture and predicted its viscosity data. Reasonable agreement with the experimental data has been observed. In conclusion, we have shown that the isomorphism principle in conjunction with the mapped viscosity EoS suggests a reliable model for calculating the viscosity of mixture of hydrocarbons over a wide pressure range up to 35 MPa within the stated experimental errors.

Critical phase behavior in multi-component fluid mixtures: Complete scaling analysis

“…In Eqs. (51) and (53) we already have ∆ρ and δt, both as functions ofρ (for fixedň). Solving the second of these equations forρ gives to leading order…”

“…Such properties could include Tolman's length, 46 dielectric constant, 47 refractive index, 48 thermal and transport properties, 45,49,50 and more generally other properties that can be obtained from the dependence of the pressure on the other variables. 51 It will be interesting to see what new physical insights can be gained from the inclusion of polydispersity and potential pressure mixing effects. We also plan to study more closely the crossover between monodisperse and polydisperse critical behaviour that one expects to see in weakly polydisperse systems, building on perturbative approaches to polydisperse critical behaviour.…”