Can fluent calculate the Joule-Thomson effect ?
 

Hi,

I'm calculating the isothermal fluid flow of CO2 in a vertical long pipe (with the diameter of 0.5 m and length of 1000m). The CO2 is injected into the pipe from top (mass flow rate inlet boudary condition) and goes out from the bottom (pressure outlet boundary condition). The operating density is set to be 0 and the operating pressure is set to be 35MPa. The absolute pressure of CO2 in the pipe is around 10~35 MPa (most of the pressure is built by gravity of the supercritical CO2 fluid).

Density-based solver and NIST real-gas fluid properties are used. However, after the calculation is converged, it is found that the entropy of CO2 decreased from the top to bottom of the pipe, which is against the second law of thermodymanics.

It seems that FLUENT didn't consider the Joule-Thomson heating introduced by gravity, however, it is written in FLUENT manual that if the coupled solver (density-based solver) is chosen for a compressible fluid, the pressure work term will be included in the calculation automatically.

It confuses me for a long time :confused:. Can anyone help me on this? Thanks a lot!

ruanbl

no one knows?

I am also trying to understand the same thing.
If you have found something, please share it with me.

Thanks.

Hi,
I have a similar problem,
Could you solve j-t effect modeling using fluent?