[amine.azzouz]

Greetings everyone
I'm doing a project about Heat pipes and i'm trying to the internal evaporation- condensation system.
System explanation:
"The heat pipe is a closed tube evacuated from air containing droplets of water.
when one side is heated the water evaporates and takes heat to the other side to condensate and goes back to evaporation side , this cycle continue and allows it to transport heat"

i'm fairly new to this so i followed a video guide online (/watch?v=hPeGvczYHMM)
i created two parts which are surfaces for symmetry reasons , one water and one air and i want the water to boil and for the vapor to go through the air part and condensate on the other side.

i have ran a simulation and got the result attached in the .gif file , the problem i'm facing is that the program is considering the water part as a closed box , there are no interactions (supposedly vapor moving through the air) between the two bodies.

i'm really stuck since i cant find any source with similar problems as mine and I'm new to fluent , so any help would be seriously appreciated.
thank you in advance

[MKuhn]

Normally in a heat pipe you have only on medium in two-phase condition. In your case water-liquid and water-vapour. Additional air will decrease the performance significantly.