4 Replies Latest reply on Sep 10, 2014 2:10 PM by Jared Conway

    Radiation capabilities in Flow and Flow with HVAC

    Shaun Erasmus

      Hi All,

       

      Basically I would like to know what the difference in capabilities is, WRT radiation in standard Flow Simulation and Flow with the HVAC module. In the product matrix it says that the HVAC module has "advanced radiation" and I would like to know what can be done in standard Flow and what it is that is considered to be advanced radiation?

       

      My understanding for now is that solar radiation can be analyzed in Flow and that absorption in solid bodies can be analyzed in HVAC?

       

      Thanks in advance!

        • Re: Radiation capabilities in Flow and Flow with HVAC
          Jared Conway

          do you have access to the help file and the technical reference? these are outlined quite well there, also in the kb.

           

          but the main thing in HVAC is that it has discrete ordinance radiation (Advanced radiation) that allows absorption, i also believe that only HVAC handles wavelength based solar radiation.

           

          so it really comes down to what your application is.

            • Re: Radiation capabilities in Flow and Flow with HVAC
              Shaun Erasmus

              Hi Jared,

               

              Thanks for the response.

               

              I do have access to the web help, but it was down for maintenance for most of the day yesterday.

               

              Basically it would be for design of an electronic component, that will be exposed to reasonably high temperatures outdoors. The electronics module is a given here for the internal components.

               

              What I would like to know is:

               

              • if the HVAC module would be required to analyze basic solar radiation (not wavelength based, but rather location based), and
              • if the HVAC module is required to apply radiation to emitted by solid bodies.

               

              I am currently reading through the online help, but any clarity on this would be greatly appreciated.

                • Re: Radiation capabilities in Flow and Flow with HVAC
                  Alexandre Massicotte

                  Hi Shaun,

                   

                   

                  Jared is referencing a technical reference guide that is stored locally in your Solidworks directory, not online. This document can be accessed following these instructions:
                  http://www.ddicad.com/blogs/techcenter/2013/07/22/the-solidworks-flow-simulation-technical-reference-guide/

                   

                  Unless you have the HVAC package, the only available radiation model is the "discrete transfer" model, whereas the HVAC package includes the "discrete ordinates" model. As Jared said, the technical reference does an excellent job explaining the assumptions made by each model, so I'd recommend examining the validity of these assumptions in the context of your system. You know best!

                   

                  Off the bat, I can tell you that a big difference between the two models is that the default model ("discrete transfer") does not allow for spectral-dependent radiation (the "gray" assumption), and cannot properly describe semi-transparent bodies. So, if your bodies are opaque and have a weak spectral dependence in the sun's blackbody peak, then I'd guess the default model is OK. But again, it's difficult to make an assessment without all the system information, so have a crack at the technical reference.

                   

                  Alexandre Massicotte

                  Design Engineer, Aavid Thermalloy

                  • Re: Radiation capabilities in Flow and Flow with HVAC
                    Jared Conway

                    radiation and solar radiation are available in the basic flow simulation package, so you should be good to go

                    DO does have some advantages, i'd suggest checking out the tech reference but the default radiatino should be fine