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Time varying boundary condition in Fluent

    • Vanesa
      Subscriber
      Hello,I am trying to simulate time varying boundary condition where after some time one of my wall should be changed as mass flow inlet with a certain amount of mass flow rate value. I went through the discussions on this forum and many other internet resources and even fluent documentation. Implementing UDF or using scheme file are the options one can use to define this time varying boundary condition was my conclusion. UDF needs strong programming skills and scheme documentation is rarely available.nI want to try scheme file for my simulation. I want to know how can we input other details of my changing boundary condition in the scheme file. Suppose my scheme file is:nn(condn   ((> (rpgetvar 'flow-time) 2.0)n        (ti-menu-load-string define/boundary-conditions/zone-type 6 wall)n        (ti-menu-load-string define/boundary-conditions wall 6 no no yes yes no 1 no 0)n        (ti-menu-load-string define/boundary-conditions/zone-type 6 mass flow-inlet)n   )n)nSo now for this wall I want it to change to mass flow inlet after 2 secs in my simulation and I want to specify its details within this scheme file befoe the run (flow direction specification method/value of mass flow rate, etc.).nHow can I do it?nPlease help.nThank you.n
    • Keyur Kanade
      Ansys Employee
    • Vanesa
      Subscriber
      Yes I can use that but I want to know how we can define the details of the boundary condition within the scheme file.nnOnce I get details then only I can load in execute commands.nnThank you.n
    • Keyur Kanade
      Ansys Employee
      You can directly use TUI commands in execute commands. No need for scheme commands. n
    • Vanesa
      Subscriber
      Thank you.nBut It is not working with TUI commands in execute commands.What exactly should be the TUI command to say Fluent to change my wall boundary condition to mass flow inlet boundary condition (with direction specification method and mass flow rate value) when time reaches 2 secs?.Please help.nn
    • Rob
      Forum Moderator
      You need activities over execute commands as the latter is every some time steps, the former triggers at a set time. nWhen you say the TUI command isn't working, is there an error or is something not happening as expected? n
    • Vanesa
      Subscriber
      It is working now. I updated this in my scheme file and then loaded it in execute commands and it is working. Following is the scheme I tried.nn(condn  ((> (rpgetvar 'flow-time) 2.0)n     (ti-menu-load-string define/boundary-conditions/zone-type 6 mass flow inlet)n     (ti-menu-load-string define/boundary-conditions mass flow inlet 6 yes yes no 11.9097 no 0 no yes yes no 1 no 1)n  )n)nnIt was this command - yes yes no 11.9097 no 0 no yes yes no 1 no 1nThis command is where we are providing the details of boundary conditions.nnThank you so much.n
    • Rob
      Forum Moderator
      Yes, the boundary TUI commands vary depending on which models are active, and that can cause issues if you have a different set up to the one the command was written for. n
    • Andrés Páliz
      Subscriber

      Hi, I´m trying to do something similar. But I'm using the VOF model and a steady state. How does the code need to be to make the change after some iterations instead of a time?

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