3 Replies Latest reply on Jan 22, 2016 8:26 AM by Amit Katz

    Vary RPM of a fan

    Hans Christian Tekol
    Hans Christian Tekol Jan 21, 2016 9:44 AM

      Hi everyone,

       

      I am simulating an inverter cooling with axial fans. Does anyone know how to vary RPM of a fan in Solidworks Flow Simulation? Because I want to see the effect of fan static pressure to thermal behavior of the cooling.

       

      I have tried changing the rotor speed (rad/s), which is corresponding to RPM, but to no avail. Let's say I use Papst 8412N fan, the default rpm is 3600 rpm. I have varied the rpm from 3600 to 50 rpm, but the results are similar.

       

      Your suggestions are highly appreciated.

       

      Thanks

      Hans

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        • Re: Vary RPM of a fan
          Amit Katz
          Amit Katz Jan 21, 2016 3:57 PM (in response to Hans Christian Tekol)

          How are you gaging the effects of the fan's RPM? Are you looking at the velocity of the wake?

            • Re: Vary RPM of a fan
              Hans Christian Tekol
              Hans Christian Tekol Jan 22, 2016 7:53 AM (in response to Amit Katz)

              Hi Amit Katz,

               

              Well actually my concern is the junction temperature of IGBT modules installed on a heatsink, which is cooled down by axial fans.

              Based on the fan's performance curve (static pressure vs RPM), I want to have higher static pressure by decreasing the RPM, in order to acommodate pressure loss of the system (inverter).

               

              I have looked into KB, online help, tutorial concerning this matter, but have't found any solution yet. Do you know if it's even possible to change the RPM of a fan in SolidWorks Flow Simulation?

                • Re: Vary RPM of a fan
                  Amit Katz
                  Amit Katz Jan 22, 2016 8:26 AM (in response to Hans Christian Tekol)

                  It sounds to me like you are using a fan boundary condition, rather than a rotating region. When you give a surface a "fan" condition and supply a performance curve, the simulation will find a balance point for that surface on the curve, depending on the intensity of pressure that the surface interacts with. As far as I know there's no way to set a point on the curve, you would need to provide a different curve for a different RPM.

                   

                  What you could do instead is actually model the fan in full detail and set it as a sliding mesh rotating region. This will simulate the physical interaction of the fan blades with the air, and you can manually specify whatever RPM you choose. Please note, this is a computationally intensive option, and the simulation can take a long time.