[Martin_Sz]

Can anyone help me to make expressions to N2 properties
Heat capacity, heat conductivity dependent on pressure value

I have simulation with heat transfer - cooling system of the gears
I need to simulate cooling with two different pressures 1 bar and 5 bars
Best regards

[tomson199]

If you know mathematical equations for this dependances, write an exspression and put it in material definion

[Opaque]

Not exactly certain what equation of state you are using. However, keep in mind that for ideal gases the specific heat capacity can only be a function of temperature, and not pressure.

You may be able to write an expression for specific heat as a function of pressure, but you will be introducing thermodynamic inconsistencies in your model.

However, if you model N2 as a real gas, then the specific heat capacity can be a function of pressure as well.

The above is not a restriction in ANSYS CFX, it is pure thermodynamics.

[Martin_Sz]

I use n2 at stp. So differences between temperaturę on gear after 100 seconds of cooling is too small about 2 degrees on two pressures on outlet 2 and 6 bars. I define this pressure on outlet because if i define on Domanin. Average pressure on this two simulations (2 bars and 6 bars) is atmospheric 1 bar on hole time of analyzes. On solver i choose thermal energy and sst. So i do not see on default setup of n2 at stp dependences between pressure and jest transfer on the gear