Hi Everyone,

I'm working on solving the Redlich-Kwong equations in SolidWorks Flow Simulation and then comparing those values to REFPROP gas properties. Stop me if it has been done before.

I'm doing this to better my understanding and to choose the best Redlich-Kwong modification to use for my gas species. 

Anyway, in the help manual describing the equations used there is a statement that says "Real Gases

Pc, Tc  and Vc are the user-specified critical parameters of the gas, F=Tr^-1.5 is the attractive term, Zc is the gas compressibility factor that also defines the a, b, and c constants." Reference the attached image. 

In the engineering database, Vc  is not a user-specified critical parameter. The critical parameter should be compressibility, Zc? Again Reference the below picture. Let me know what you think..