two-phase flow with a single phase simulation
 

Hello everyone,

I tried to do a simulation of heat pipe which exposed to a hot air at the heat pipe external wall. The flow inside the heat pipe is a two-phase flow condition (water-vapour) and the heat pipe external surface is a single phase flow (only expose to air)

I used VOF model +UDF, set vapour as primary fluid, set water and air as secondary fluids. Before the simulation begins, I patched the heat pipe external volume with air and water inside the heat pipe.
I noticed that external volume truned back to vapour phase after the simulation completed. :confused::confused:

I wish to know how do you setup this kind scenario in FLUENT? Thank you.

Regards
Lawrence