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Two independent fluids (heat exchanger) – Coupled pressure problem?

    • Moritz Imhoff

      Dear all,

      I'm very new to Ansys Fluent, so hopefully you can understand my problem anyway.

      Ansys Fluent 2023 R1

      I'm trying to model a simple heat transfer/heat exchanger problem (first static, later transient with patched temperatures). 

      I defined two fluids fluid1 and fluid2 with an inlet and outlet. It appears that the fluids are coupled via global pressure settings. I can not achieve reasonable flow conditions or the simulation results in the shown error. -reverse flow in all outflow faces and floating point exception

      I do not mind the pressure settings, as this is not important for heat transfer results. Later, I want to patch inlet conditions in each time step via a journal. This solution worked quite well with a previous case, but only one fluid and fluid region.

      Is there a solution to this problem?

      Best regards


    • Rob
      Ansys Employee

      Switch "outflow" for "pressure outlet" for a start. Then write 100 times, "I will not use outflow boundary conditions again". 

      The more general issue is that Fluent currently only has one operating pressure value. Assuming only one side is compressible, use the operating condition there and then adjust the result on the liquid side. 

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