Fluids

Fluids

Discrete Phase Model(DPM) interaction/ particle treatment/ injection

    • Anadi_Mondal
      Subscriber
      Hello,
       
      According to the ANSYS Fluent User Guide 2020R1(page 2097), if I choose under-relaxation factor 0.5, 20 continuous phase iterations per DMP iteration, then 10 source term updates are required for the DPM sources to reach their final value. So, at least 200 continuous phase iterations are required after any change to DPM sources. Do I need to select the 200 Max Iterations/Time step during the 'Run Calculation' for the above case?
       
      Or, what will happen if I select the 50 Max Iterations/Time step for the above case?
       
      Moreover, which source update will ANSYS consider if I select ' update DPM Sources Every Flow Iteration' and a value in 'DPM Iteration Interval' together?
       
      Regards,
       
      Anadi
    • DrAmine
      Ansys Employee

      Do not reduce the default URF only if the case cannot run stable with that (transient default is at 0.9). Try to update the source terms more frequently within a time step and perhaps track the particles with a smaller time step. update DPM Sources Every Flow Iteration is recommended for transient particle tracking.

       

    • Anadi_Mondal
      Subscriber

      Thank you Amine! I will try to run the simulation with default URF and select update DPM sources every flow iteration. Here you are recommending updating the source term frequently and tracking the particle with a smaller time step. However , would you tell any numerical value( how frequently/ how much smaller) for these? You know URF, DPM Iteration Interval and #of DPM source term have direct relation. Could you give an example considering these with Max Iterations/time step?

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