[Mohamad.Baassiri]

Dears,

I am simulating a free jet CO2 through a micro-orifice. I have supercritical upstream conditions, and subcritical downstream conditions. I am using Peng Robinson real gas equation. Model works perfectly fine as long as the inlet temperature is >310 K. If I reduce the the inlet temperature to less than that, the model diverges and I get the error 'Invalid Cp (- xxxxx) at T= xxxx'.

Note that I am starting from a converged solution at T=310 K, and slightly changing T to 308 K (for example). I understand that this is a pseudo-critical region where properties of CO2 vary abruptly. So my question is would someone kindly suggest how to deal with this issue in Fluent?

Thank you,