4 Replies Latest reply on Mar 17, 2015 5:12 PM by Amit Katz

    Flow Simulation: problem with a fan

    Gabriele Ranucci

      Hi everyone,

      I'm new to SolidWorks Flow Simulation and I have to simulate the air flow through an enclosure with electronic components in it.

       

      My model is the one shown in figures a.jpg and b.jpg attached to this post (At the moment I've only modelled the openings through which air enters the enclosure and the fan that lets air in).

      To analyze this model I would create the simplified model shown in figure c.jpg and then I would apply the following conditions:

       

      - on the inner surface of the lid (that is necessary to perform an internal analysis), I would apply environmental pressure boundary condition and then perforated plate condition (because in the real model there are lots of small vents (figure d.jpg)

      - then I would model the fan as an internal fan and consider the surface in front of the lid as the face through which air enters the fan (e.jpg) and the opposite surfaces as the face air exits the fan

       

      Do you think this is a good way of solving this problem? Or should I treat the fan as an external inlet fan (because, although the fan is inside the enclosure, it lets air in)?

       

      Thanks in advance.

        • Re: Flow Simulation: problem with a fan
          Jared Conway

          start with a simple lid, a cylindrical split line on the inside of your box

          internal analysis

          use an external inlet or outlet fan

           

          that is a pretty good approximation

           

          from there, i'd do an external analysis and an internal fan

          that way you can see whats happening on the inside and outside

           

          then you can start getting closer to reality with perf plates or fan covers...etc. but I wouldn't start there

          • Re: Flow Simulation: problem with a fan
            Amit Katz

            Jared gives some good advice. I assume that the components and the layout inside your model (which do not exist yet, according to the screenshots) is what is really going to be interesting to you, so maybe don't focus so much on detailing every swirl and vortex that comes from your fan. Just pick a fan and use the manufacturer supplied fan curve, for starters.

             

            The Flow Sim tutorial package has an excellent chapter covering small electronics enclosures, I recommend working through it (if you haven't yet) to get a feel for how the software will handle your design challenge.

            • Re: Flow Simulation: problem with a fan
              Gabriele Ranucci

              I've already gone through the tutorial but I couldn't find an example with a fan inside an enclosure.

              So, if I understand well, you are telling me than in this case I can model that fan as an external inlet fan. Is that correct?

              • Re: Flow Simulation: problem with a fan
                Amit Katz

                That will work, but just keep in mind that it will not take into account any perforated sheet you might want to cover it with in the future. To keep things simple you could model a section of the case as a separate body and model a circular cylinder for the fan. Use the inward face of the cylinder as your "external inlet fan" for now, and in the future you can adjust your model to include an internal fan and a perforated plate without having to adjust your geometry.