1 Reply Latest reply on May 7, 2013 3:43 PM by Jared Conway

    PCB Heat Sink and Radiation Modeling

    Jason Fruh

      Guys/Gals,

      I have spent a few hours searching the forum and could not find an answer, but my apologies if it is out there and I couldn't find it...

       

      I am looking for help on the best method for modeling radiation heat transfer from a heat sink.  Specifically, I am modeling a PCB with various ICs/heat sinks enclosed within a vented plastic enclosure.  There is no fan so convection is natural, driven by gravity and the temperature gradient.  I have read that radiation can account for up to 25% of heat transfer under natural convection, so I don't think I can ignore this despite the relatively low temperature of the heat sink (100degC).  Additionally, one of the key specifications is the outside enclosure surface temperature, this cannot get too hot or it will be dangerous for consumers to touch.

       

      Basically, I am confused about the proper application of "environment radiation", "radiative surfaces", and "radiation sources".  I have read the help files and tutorials, but I am still confused.  I would like to know both "how to set up this analysis" and "why you chose that set up method".

       

      Thanks,

      Jason

        • Re: PCB Heat Sink and Radiation Modeling
          Jared Conway

          you probably don't have the HVAC module but have you checked the halogen lamp tutorial? there is some good information in there.

           

          also, have you considered a flow simulation training class to augment your sim knowledge? in addition to that, at hawk ridge systems my team offers one-on-one training on specific problems like the one that you have. basically we walk you through setting up your problem, all the assumptions..etc. essentially what you're asking for.

           

          but to answer your questions more generally.

           

          environmental radiation = radiation from your component to an "environment" far far away. i would recommend having this on as it happens in almost every situation.

           

          don't play around with radiative surfaces at first. start with black body and then tune the surfaces based on finish and color afterwards.

           

          radiative sources, don't worry about that at first.

           

          the other question you'll probably want to ask yourself is if you want to run this as an internal or external analysis.