Define an equation of State
 

Hi,

I struggle since days to see a density in my simulation. (a supersonic 300K gas jet of H2 in pipes with a low background pressure of 1000 Pa roughly)

I simulate this with H2 as "constant property gas" how I can set the density by using the built of Redlich Kwong equation?

I tried all the tab without success and the help index doesn't help. Do i need to define the density expression before running the simulation ? Because i get strange results ( such as negative absolute pressure) despite my 0 Pa reference pressure.

Thx

Florian M.