3 Replies Latest reply on Sep 21, 2017 10:16 AM by Bill McEachern

    Different values for "Point Goals" and "Point Parameters"

    Roman Lech

      I'm performing a study and I'm measuring pressure at a point.  I've added a point goal to the edge of a circle which creates a point at its center, for convergence control and to monitor the values during the calculations..  Comparing the value from the goal to the value from a point parameter at the exact location yields me completely different values...

      Point Goal: 14.4236PSI

      Point Parameter: 13.943PSI

       

      Am I missing something because from my understanding these values should be near identical...  I've tried multiple runs with a denser mesh and very dense local mesh around the point I am measuring with similar results...

       

      Hope you can help!

        • Re: Different values for "Point Goals" and "Point Parameters"
          Bill McEachern

          I have never used the point goal in all my years of using Flow which is approaching 20. I suspect the issue is that you are comparing total pressure to static pressure though from what was shown its hard to tell. No qualification is given in the point parameters on which pressure it is giving you but maybe that was in the selection list.

          I have never used a point goal to instrument a model because all sensors have a finite volume. I put in a small volume typically when I instrument a model and use  volume goals. These goals and volume parameters provide the same array of values for a given parameter like pressure - total, static and dynamic.

          • Re: Different values for "Point Goals" and "Point Parameters"
            Roman Lech

            Thanks for the response Bill.  I havn't used Point Parameters before either until today when I had a bit more time to tinker with the results, and that is when I saw this discrepancy.  I think you nailed it with what pressure value a point parameter is actually giving me. I can re-run the simulation and record a static pressure goal at the point and see if that correlates with the point parameter.

             

            Also thanks for the tip on the small volume goal.  Ill look into giving that shot. 

             

            Regards,