Use of molecular shape factors in vapor‐liquid equilibrium calculations with the corresponding states principle

Abstract

= density = solution vector for O.D.E. $ Q = Thiele modulus D = spatial region Su bscripts e = equilibrium state o = initial state y z Superscripts * = steady state condition = derivative with respect to y = derivative with respect to zCalculation of fugacities of components in a goseous or liquid solution directly from the corresponding states principle requires an improvement in the pseudo-critical constonts for the mixture. The derivation of the pseudo-criticals must take into account deviations from the simple two parameter corresponding states principle which require additional parameters incorporated into the definition of the pseudo-criticals. I n this work porometers called moleculor shape factors are introduced into the pseudo-criticals. A generalized correlation for these shape factors is presented.Use of the shape factors greatly improves the calculation of vapor-liquid equilibrium ratios for nonpolar hydrocarbon mixtures with large differences in moleculor size and shape. Excellent results are obtained both in the low pressure and in the retrograde region when the pseudo-reduced properties of the vapor and liquid lie within the range of accurately known properties of a reference fluid and the reduced temperatures for each component is greater than opproximotely 0.6.

Numerical study of heat transfer deterioration of turbulent supercritical kerosene flow in heated circular tube

“…The thermodynamic and transport properties of China RP-3 kerosene are determined by a 10-species surrogate proposed in our previous work [16] and the Extended Corresponding State method (ECS) [18] with Benedict-Webb-Rubin equation. The species and mole fractions of the surrogate are listed in Table 1.…”

“…The Reynolds averaged NavierStokes equations are solved with a two-layer turbulence model, including the RNG k-e turbulence model and the Wolfstein one-equation model in the near-wall region. Thermal and transport properties of kerosene are determined by a 10-species surrogate proposed in our previous work [16] for China RP-3 aviation kerosene with the Extended Corresponding State method (ECS) [18]. The present numerical method is validated via study of mesh dependency and comparisons of wall and fuel temperatures with experimental data.…”

Extension of the shape‐factor method to highly polar systems

“…To deal with t h e latter, Leach et al (1968) have introduced the shape-factor method, an extension of the two-parameter corresponding states principle, in which an arbitrary fluid is made conformal to a reference fluid by relating the reduced properties of both fluids via dimensionless factors which depend on the shape of the molecules. This method has been widely applied to determine densities, vapor-liquid equilibria, enthalpies, critical states, surface tensions, thermal conductivities, viscosities, Joule-Thomson coefficients and azeotropic states.…”

Numerical investigation on flow and convective heat transfer of aviation kerosene at supercritical conditions

“…Navier-Stokes equations are solved by using RNG k-ɛ turbulence model with low Reynolds number corrections. The thermophysical and transport properties of the kerosene are determined by a 10-species surrogate [11] and the extended corresponding state method (ECS) [14] combined with Benedict-Webb-Rubin equation. The paper investigates properties of flow and convective heat transfer of kerosene with different wall heat fluxes and discusses the associated physical mechanisms.…”

“…[11] and the extended corresponding state method (ECS) [14] combined with Benedict-Webb-Rubin equation considering the real gas effect. The component and mole fraction of the surrogate are listed in Table 1.…”