[marcusaurelius]

This is a general question and not related to specific CFD software as this problem can be seen in all softwares.

I am trying to simulate 2D saturated pool boiling case with constant heat flux boundary condition on solid wall (having conduction) in ANSYS Fluent. I use LEE model and VOF interface method is used.

I am seeing that wall temperature keeps rising and rising unrealistically too high in transient simulation with time. Even after waiting for 20 seconds of simulation, the wall temperature does not achieve a pseudo-steady-state situation where temperature stabilizes and does not increase further.

What fundamental mistake am I doing in this simulation? In Past I tried openFoam as well, but I had encountered same problem as well.