Fluids

Fluids

Negative computed saturation temperature w Lee Evaporation Model

    • rachels1001
      Subscriber

      I've been using the Lee Model to model evaporation-condensation in a Eulerian multiphase simulation w Fluent. My evaporation and condensation coefficients were 0.3, but then I changed it to 0.1, as the Fluent User guide recommends. I haven't started fine-tuning them yet. 


      When I run the simulation, I am getting the error message that there is an "Error at Node 0: The computed saturation temperature <= 0.0". The pressures specified in the simulation initialization range from -4700 Pa to 30 Pa gauge; however, I have run previous versions of this simulation with the same evaporation constants and pressures without errors. 


      Is there any commonly known pitfalls that cause this kind of error?


      Thanks!


      Claire

    • DrAmine
      Ansys Employee

      Is the saturation temperature a non constant value? Are you using a table or profile for it? 

    • rachels1001
      Subscriber

      I've been using constant values of 373.15 K for normal water-evaporation and 573.15 K for bound-water evaporation

    • rachels1001
      Subscriber

    • DrAmine
      Ansys Employee

      Which version?

    • rachels1001
      Subscriber
      The case was created in 19.2 and it does run on my computer in version 19.2.

      However, due to computational power requirements, I have to run the simulation on a network with only earlier versions (18.2). This is where I receive the error about sub zero calculated saturation temperature.

      Is it possible there is a problem with the backwards compatibility?
    • rachels1001
      Subscriber

      Update: It was because I was creating a file in version 19.2 and running it in version 18.2. I recreated the fluent case file in 19.1 and ran it on the network with the same version and the error no longer appeared. 

    • DrAmine
      Ansys Employee
      Thanks for the update. Please mark this as Is Solved.
    • DrAmine
      Ansys Employee
      Please update to the latest versions as there were some issues when using more than one mass transfer mechanism which have been fixed.
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