Learning Forum

[jackzhe551]

IN vof/mixture model  ,I calculate the one fluid heat exchanger by fluent，I only care the outlet temperature and pressure，can steady mode be used for calculation？

[Rob]

It depends. Steady boundaries don't always mean you have a steady flow field. 

[jackzhe551]

But if steady mode cannot calculate，transient mode cannot calculate，too？

[jackzhe551]

could you help me remind Prashanth that he always does not reply to me, maybe he did not see.phase change hydrogen in heat exchanger (ansys.com)

[jackzhe551]

If we do not calculate the physical properties from NIST, where can we get the hydrogen physical properties polynomial?

[Rob]

Textbooks? There are other databases and methods, however it's not data I can share as I'm very limited in what I can do on here. 

[jackzhe551]

 

Do 2020 R2 support importing Rgp files？ In the user guide for 2020， I cannot find the RGP table tutorial.Additionally,I cannot understand the tutorial,like fig shows,these words are written in a txt file or not?and then import into fluent udf?and the commands are written in console to launch python?

 

[Rob]

That's the 21R2 documentation, so it may not be available in 2020 as there's no reference to RGP in 2020R2 Fluent documentation. The above looks like Python, but also refer to system coupling. 

[jackzhe551]

A strange thing happened, my heat exchanger cold fluid (H2) inlet is at 22K, while the hot fluid inlet is at 360K. The cold fluid is H2, and I used NIST real gas, but without using tables, so there shouldn't be any limitations on the range of property parameters. However, in the calculation, it shows that the temperature has dropped to 13.939K. I expected the cold fluid to start heating up from 22K, so how could it drop below 22K? I'm puzzled that NIST doesn't seem to work well. Could you please provide me with a polynomial property equation for H2? Thank you."

[Rob]

We don't provide fluid material properties other than what's in the Fluent solver, and I'd treat those with some caution. Check the materials input for whatever you've set up, and both operating and boundary conditions.