Learning Forum

[abhnv_01]

I am trying to simulate a heat pipe in (2D) which has three sections:

1. Evaporator - Constant heat flux (boundary conditions)
2. Condensor - Constant temperature (boundary conditions)
3. Adiabatic section - Zero heat flux (boundary conditions)

I am using VOF multiphase model -> Evaporation - condensation model -> Lee model. 

Transient simulation with gravity and implicit body force formulation.

Time step size = 0.0001 (1E-04).

The simulation works well for first 10000 time steps (1 seconds of flow time) and then this error where global courant number exceeds 250. 

 

But here is a mystery, the simulation runs well with constant temperature boundary condition at the evaporator.

 

I want results with constant heat flux and I am not able to track the error why it is happening.

Any help will be highly appreciated. 

[Rob]

Answered here  https://forum.ansys.com/forums/topic/why-cfl-exceeds-250-for-constant-heat-flux-bcs-but-works-well-with-constant-t/