# How does ANSYS Fluent calculate its enthalpy?

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 November 28, 2015, 05:46 How does ANSYS Fluent calculate its enthalpy? #1 New Member   Join Date: Nov 2015 Posts: 4 Rep Power: 10 Hey guys! I am working with ANSYS Fluent at the moment and now there appeared a question. I wrote the User-Defined Funtions, one for the density and one for the viscosity - both dependent on the enthalpy. While running the calculation with one of these UDFs I set the other parameter (density or viscosity) constant. All other settings stayed the same in those two calculations. Now ANSYS Fluent gave me different enthalpy-values in both calculations. Now I am a bit confused because the density and the viscosity respectively should be calculated based on the enthalpy-values and not the other way around. So can anyone help me and explain to me why I have different enthalpy-values when I just changed the terms for density and viscosity? Thanks up front! Last edited by RebeccaKn92; November 28, 2015 at 07:45.

June 4, 2018, 05:20
#2
New Member

DU Shen
Join Date: Nov 2016
Posts: 14
Rep Power: 9
hi, did you figure out the enthalpy calculation in FLUENT?

Quote:
 Originally Posted by RebeccaKn92 Hey guys! I am working with ANSYS Fluent at the moment and now there appeared a question. I wrote the User-Defined Funtions, one for the density and one for the viscosity - both dependent on the enthalpy. While running the calculation with one of these UDFs I set the other parameter (density or viscosity) constant. All other settings stayed the same in those two calculations. Now ANSYS Fluent gave me different enthalpy-values in both calculations. Now I am a bit confused because the density and the viscosity respectively should be calculated based on the enthalpy-values and not the other way around. So can anyone help me and explain to me why I have different enthalpy-values when I just changed the terms for density and viscosity? Thanks up front!

 Tags density, enthalpy, udf, viscosity