Fluids

Fluids

parameter of convection

    • Jonn
      Subscriber

      good morning

      I am studying the temperature change of a wall, but when I enter a parameter Convection for both sides,

      When starting the calculation, the temperature does not take its initial value as 303 K .

      But when I have one parameter of convection , I don't have this problem

      Is there a modeling method?

    • RK
      Ansys Employee
      Hello,
      You can set the initial value to 303 K and initialize it.
    • Jonn
      Subscriber
      Hello
      When I set the initial value to 303K and initialize it. The results appear like this
      The initial temperature should be when the calculation is started
      T_inlet= 303k
      T_outlet= 297k
      Is there a way to set each side individually?



    • DrAmine
      Ansys Employee
      I do not understand the setup. Inlet or pure walls?
    • DrAmine
      Ansys Employee
      Okay you have only solid with two walls having mixed or thermal boundary condition or at least the left one using temporal profile. I do not now understand the problem as I do not see a problem
    • Jonn
      Subscriber
      I am studying the temperature change at the outlet side of a single layer wall
      The entrance and exit is a wall
      I give the inlet side a variable temperature that starts with a value 303k and increases with time. File UDF and a heat transfer coefficient h=24
      For the outlet side, i give it a constant temperature 297k and a heat transfer coefficient h=7
      But when I start the calculation, the initial values of the two walls are not the same as the values I entered ''see the picture ''



    • Rob
      Ansys Employee
      Can you post an image of the mesh?
    • Jonn
      Subscriber
      thank you for replying
      To simplify the idea I said I have one layer but I have two layers
      and for the mesh I think is good






    • DrAmine
      Ansys Employee
      At inlet you give T=303 K + 1 K /15 [s] * time and HTC. So actually you are not providing the temperature boundary directly but a robin like BC: convective BC. Fluent will need to calculate the boundary temperature based on that: balancing the convection outside with conduction inside.
    • Jonn
      Subscriber
      OK thank you sir
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