[Andrea159357]

Hello, i'm trying to analyze a condensation process in a pipe line using VOF mixture model but i got some problem understand how it works. I set Fluent as this tutorial said, https://www.youtube.com/watch?v=rRsdQC20NvA, exept for operationg pressure that is P = 8 [bar] and saturation temperature Ts = 443.15 [K].

T inlet = 473.15 [K] where water vapor density is 3.8314 (heated steam). When i set material, i defined water liquid and water vapor but at what condition? I mean, water liquid is not really a problem; i defined all coefficients at saturation temperature and pressure.
Different story is for water vapor; do i must defeine density at saturation or in heated condition?

[CFD-fellow]

I think defining density as a linear function of temperature is a good idea.

[jibinyg]

Originally Posted by Andrea159357

Hello, i'm trying to analyze a condensation process in a pipe line using VOF mixture model but i got some problem understand how it works. I set Fluent as this tutorial said, https://www.youtube.com/watch?v=rRsdQC20NvA, exept for operationg pressure that is P = 8 [bar] and saturation temperature Ts = 443.15 [K].

T inlet = 473.15 [K] where water vapor density is 3.8314 (heated steam). When i set material, i defined water liquid and water vapor but at what condition? I mean, water liquid is not really a problem; i defined all coefficients at saturation temperature and pressure.
Different story is for water vapor; do i must defeine density at saturation or in heated condition?

Hi,
I am also dealing with the same problem of steam condensation in water with vof multiphase model. But now as the iteration progresses, the steam keep growing in upward direction(-g) opposite to the direction of water.
Have you used any udf for condensation model?
Any help to this problem will be great thing.
Thanks in advance.

[Andrea159357]

No, i didn't use UDF for condensation but you can use it. I ran the model with fluent condensation model just for a qualitative test. if you need really accurate results it's better you write your own udf

[Andrea159357]

For vapor model i think i should have use equation of state.