Learning Forum

[ssyadav]

Dear Amine

I hope you are safe from the ongoing pandemic and pray that you remain so.

 I am sorry I am bugging you again and again.

I am stuck at another step, this time related to how to incorporate spinodal data into the RGP tables.

I simulated two different fluid flows inside nozzles.

Case 1) Flow of water in Moses  and Stein nozzle, Real Gas Data: IAPWS equation for water

Case 2) Flow of CO2 in another nozzle by Nakagwa, Real Gas Data: (a) RGP file for CO2 based on REFPROP, (b) Redlich Kwong EOS

I am following Ansys CFX guidelines which say that first switch off the nucleation process so that vapor super-cooling develops and then allow nucleation for the phase change process to occur.

The issue is: I am able to see significant water vapor super-cooling even after phase change in the nozzle with IAPWS data for water. Whereas, the super-cooling vanishes for CO2 once phase change starts. These happens with RGP files as well as with Redlich Kwong equation of state for CO2.  The figures attached above show things more clearly.

Now the CFX manual says that IAPWS library extends to metastable regions.

I am writing my own RGP file generator based on REFPROP.

I have two questions:

1) How to force CFX solver to read metastable data for CO2 when using Redlich Kwong equation of state. Any expert parameter for it?

2) Where I can find more information on the spinodal data to be put in RGP files?

Thanks once again for all the help till now.

Regards

Shyam