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 constatn heat flux, I am not able to track the error, any help will be highly appreciated. 

[SRP]

Hi,

I suggest to try variable time stepping in order to automatically change the time-step. It is better to use the variable time stepping method to control the CFL under limit. The solution will be stable with the variable time stepping method.

Thank you

Saurabh