Talk:Twu-Sim-Tassone equation of state

a and b

Dear Joseph,

I have replaced the values that you added for $a$ and $b$ to be those found in the original publication (Eqs. 3 and 4 in Chorng H. Twu, Wayne D. Sim and Vince Tassone "A versatile liquid activity model for SRK, PR and a new cubic equation-of-state TST", Fluid Phase Equilibria 194-197 pp. 385-399 (2002)). The values that you inserted appear as Eqs. 3.3 and 3.4 in the Reference Guide (June 2005 R350 Release) of the UniSim Clean Fuels Property Package. Without having gone through the algebra, I shall err on the side of the caution and assume the values of Twu et al. are the correct ones. All the best, -- Carl McBride (talk) 12:41, 7 November 2011 (CET)

Addendum: the prefactors of $a$ (0.427481) and $b$ (0.086641) appear to be close to those of the Redlich-Kwong equation of state. -- Carl McBride (talk) 17:31, 7 November 2011 (CET)