I am trying to setup a vapor chamber, which in my case is a hollowed rectangular box. It is used as a way to transfer heat. Outside material is copper. Hollowed space is filled up with a small portion of water under low pressure while the rest portion of space to be air . So when the vapor chamber is heated up from bottom, heat got transferred from the bottom copper layer to the hollowed space. The small portion of water under low pressure will be vaporized (absorb heat)and the steam will rise to the top surface of the hollowed space. When top layer of vapor chamber cools down, the steam will be liquefied(release heat) and dropped down on the bottom surface of hollowed space again.

So the question is how to setup a vapor chamber with phase changes in a simulation like this? (i can setup the heat source and cooling source)