Fluids

Fluids

Multiphase flow, floating point exception

    • kuuku.botchway
      Subscriber

      Hi everyone, I'm currently running a multiphase VOF problem with three phases, implicit formulation for volume fraction parameter, implicit body force activated, a polynomial function for the surface tension coefficient for each of the phase pairs with surface tension modeling turned on.  For the flow a k-epsilon viscous model is used with enhanced wall treatment, thermal effects and  curvature correction activated.  For one of the fluids I have a polynomial function with temperature as the variable.  I've been running into an issue where I'm receiving a floating point exception around when the fluid gets converted into the other fluid T=

      This is the console message I received before the floating point exception.  Any assistance would be very helpful

    • DrAmine
      Ansys Employee

      Okay: first start simple and use a plain SST turbulence model (without any additional sub-models). Use a constant surface tension and try again. You need to find out the reason for this behavior: it actually starts diverging at the beginning of the time step. 

      Can you  describe bit more the problem you are trying to model?

      • kuuku.botchway
        Subscriber

        Hi, soo after further troubleshooting it seens ti be a problem with Enhanced Wall Treatment in the K-Epsilon model.  Would you have any insight as to why that is?

    • kuuku.botchway
      Subscriber

      Hi, Thanks for the reply.  Soo I've attempted to run the simulation with a constant surface tension previously and received the same error.  I recently just attempted the k-epsilon model without any additional options (no enhanced wall treamtmant and thermal effect) and a constance surface tension now the issue seems to have gone away, but I'm not getting the results I needed.  I'm currently testing if the material I'm using is causing the issue

    • pv00170
      Subscriber

      I got the same problem "floating point" and it was due to inflation.

      When I removed inflation, no floating point appeared.

      • pv00170
        Subscriber

        Also, if I used inflation I reduced the time step and now is working

Viewing 3 reply threads
  • You must be logged in to reply to this topic.