5 Replies Latest reply on Apr 15, 2013 3:07 AM by Jared Conway

    Get Avg Temperature of a Fluid Subdomain?

    Kevin Carpenter

      I have defined a fluid subdomain inside a hot box of electronics.  So what's the avg air temp of the subdomain?  Just can't get started on this issue.   Can't define a Volume Goal on the subdomain.  Can't define the subdomain as a solid or feature.  Can't define a Volume Parameter on the subdomain.  Wasting time and getting nowhere.

       

      Kevin Carpenter

        • Re: Get Avg Temperature of a Fluid Subdomain?
          Jared Conway

          there was a posting a little while ago that was similar. in flow simulation you need something to use for reporting. in this case you'd need a solid the shape of the subdomain so that you could create the volume parameter. you can do this by creating the volume yourself through combine/subtract commands or you could use the check geometry tool in flow to create the fluid volume, drop it into the assembly, disable it and use it for your volume parameter.

           

          unfortuantely regardless of what you do, you're going to have to rerun it to be able to use that new geometry for reporting. if that isn't possible, I'd create a bunch of cut plots, do some probing, take all the data and do an average.

           

          that being said, reporting average on a subdomain sounds like a great enhancement and you should find one already in the system for being able to add geometry for reporting without rerunning.

            • Re: Get Avg Temperature of a Fluid Subdomain?
              Kevin Carpenter

              Close, but I had also noted "Can't define the subdomain as a solid or feature".  Attempting that is so stupefyingly difficult that it is effectively impossible.  None of the other posts on this issue were satisfied, either.

               

              So that's 2 improvements to Flow Sim that appear necessary:  1) enable a Volume Goal on a Fluid Subdomain  2) enable conversion of a Fluid Subdomain to a part.

               

              Even though I can't define a Volume Goal on my Fluid Subdomain it remains useful for defining an initial temperature that's higher inside the box.

               

              Thinking inside the box, I suddenly realized I could define a Lid floating inside the Fluid Subdomain, then define a Surface Goal for avg temperature thereon.  I imported an ultra-thin ring on which to define the Lid.  Hot air convects in both directions through the Lid, comprising a passive thermometer sampling the Fluid Subdomain.  A successful workaround, and easy.

               

              Kevin Carpenter

                • Re: Get Avg Temperature of a Fluid Subdomain?
                  Jared Conway

                  "Can't define the subdomain as a solid or feature". > for a fluid subdomain, all you need is a unique space and to choose a face inside that domain to define it.

                   

                  2) enable conversion of a Fluid Subdomain to a part. > you can do this, just use the check geometry tool to create the fluid volume. you can't do subdomains individually, but you can do all of them.

                   

                  regarding your workaround, take a look at component control. your ring is a good workaround, but you could just make it solid and then component control it out. that would allow you to use it as a sensor but not block any flow like your ring might.