I am currently performing the design of a centrifugal compressor working with supercritical CO2 and I wanted to know if the NISTtoRGP application it was posted before can be used for generating the properties table in that state.
I have tried to get values from 1 MPa to 30 MPa (Pcrit=7.37MPa), but it is a bit strange because while creating the tables this message appears:
TPRHO failed so extrapolating 2D data.
P/Pc=(increasing factor until reaching the critical pressure)
I have seen that this does not happen if I just go beyond the critical point.
Can anybody help with this? How can I create a look-up table that include two-phase and supercritical states?
In addition, when I run a simulation with the rgp file I am attaching and my simulation quickly "converges" after like 4 iterations after clipping a lot of variables and putting a lot of walls in the outflow region to avoid reverse flow!!! A total non-sense... Any guesses what is going on?
My inlet conditions are the following ones, just in case it helps: