Fluids

Fluids

Radiation Equilibrium Thermal Wall Condition

    • CFDGer
      Subscriber

      Hello,

      I want to model the wall in my simulation in the state of radiation equilibrium.

    • Karthik R
      Administrator
      External radiation temperature sets the temperature of the external radiation source / sink to be used for the radiation condition. This is not meant solving internal radiation.nIf you would like to include internal radiation in your computational domain, I'd strongly recommend that you turn on the 'Radiation Models'. This will add another additional tab to your wall boundary condition selection, which will show the option of marking 'Internal Emissivity'. Please have a look at this link from the Fluent User's Guide.nI hope this helps.nThanks.nKarthikn
    • CFDGer
      Subscriber
      Hello Karthik,nnthank you very much for your reply.nSo if I set the Radiation Model to gray P-1 (Number of bands is set to zero) and I choose an arbitrary value for my Internal Emissivity of my Wall (for example =0., then the radiation heat flux is in equilibrium with the heat flux to the wall of my object? (I am simulating hypersonic external flow around an object).nAnd I saw that for the Inlet and Outlet BCs there is added the Radiation Tab in which I can choose the External Black Body Temperature Method and the Internal Emissivity. if I leave the default values for this BC, this doesn't affect the Inlet and Outlet BC? nI just want to get the radiation equilibrium thermal BC for my wall and everything else should remain the same as if the Radiation Model was turned off.nnThank you very much!n
    • Karthik R
      Administrator
      In order to have internal emissivity modeled at the walls, you will need to turn on Radiation. Turning on radiation will of course have its consequence as it will add another mode of heat transfer. So, you will need to worry about that. nBut, when you turn on the radiation, the radiation conditions at the wall will automatically ensure an equilibrium condition at the wall boundary. nI'd carefully check how your radiation is interacting with other models.nThanks.nKarthikn
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