Why CFL goes beyond 250 for constant heat flux bcs?

    • 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
      Ansys Employee

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


Viewing 1 reply thread
  • You must be logged in to reply to this topic.