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Scale a heat flux profile through time in Fluent

    • Allan Gilmour
      Subscriber

      Hello!
      I would like to model in Fluent a heat flux in a wall that has a given profile, but scale this profile through time to match the observations of an experiment. In other words, I would like to keep the "footprint" of the heat flux while the magnitude goes up and down through time. 
      I already tried to create a csv profile with (x,y,z,W/m2,time) and gave some tries at UDFs, but no success so far.
      Would anyone know how to do it? 
      Thanks in advance and have a great day! =)

    • Rob
      Forum Moderator

      Transient profiles assume a single value that varies with time - the format is different to the steady profiles that vary with position. 

      However, in 2023R2 there's an option to use profiles in Expressions. If you create an expression to calculate the multiplier can you then have a second expression that's the profile*multiplier and use that as the boundary condition? I've not tried it so it may not work. 

    • Allan Gilmour
      Subscriber
      Hi Rob! Nice! Thanks a lot! I will try it!
    • Allan Gilmour
      Subscriber

      Hi Rob,

      Sorry for the long time to come back to it, getting 23R2 took me longer than expected! I think I am having trouble with the syntax for expressions with profiles, would you know how to create them?

      I tried looking in Help and in forums, but could not find the correct way to do it =/

      Have a great weekend! =)

    • Rob
      Forum Moderator

      Can you have two profiles in the "profile" call? It's a new feature so try just calling one of sim.4 or iabs

    • Allan Gilmour
      Subscriber

      Ah, it is a single profile, sim.4 has 4 columns: x,y,z,iabs -> iabs stands for intensity, absolute. =) 

      I actually selected it from the profiles button on the right and that is how it appeared in the expression. If I remove 'iabs', I get an error "argument 2 is invalid", but if remove 'sim.4', the error remains as "invalid syntax. Perhaps you forgot a comma?" =/

    • Allan Gilmour
      Subscriber

      Sometimes I also get "name 'W' is not defined" when I try to juggle with it.

    • Rob
      Forum Moderator

      W will be the units. In which case, I don't know, and can only really point you at the documentation. 

    • Allan Gilmour
      Subscriber

      Alright, thank you very much, I will re-read it.

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