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inaccurate redlich-kwong properties for transcritical CO2

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Old   October 20, 2009, 11:32
Default inaccurate redlich-kwong properties for transcritical CO2
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Hi everyone!

I'm using CO2 for my simulation and the inlet is at transcritical state (10MPa, 35C). I've used redlich kwong equation of state and increased the range of the table generation and max points. However when I checked the results for density (well converged solution) at inlet, it was about 20% lower than compared to REFPROP (@10MPa,35C). Do you have any suggestion please? Thanks a lot!

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Old   October 27, 2009, 17:06
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No easy solution. RK is likely not valid in that range. I think you'll need to create an RGP table (see doc). I see that CFX 11.0 has a low and high pressure rgp table available for carbon dioxide (.../ANSYS Inc/v110/CFX/etc/materials-extra), but for some reason I don't see those in 12.0. Check the valid range on those built in tables too.
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Old   October 28, 2009, 00:34
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Thanks stumpy! Now I'm creating RGP tables for the range of my problem. The available rgp table for CO2, though for "high pressure", is still below my range. Thanks again!
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