1 Reply Latest reply on Feb 3, 2010 10:01 AM by Bill McEachern

    Problem with fluid volume definition

    Alec Chalmers
      I am trying to define a project in Flow Sim 2010 SP2.1 on a fairly large internal flow design. The assembly has a full 3 axis gimbaled device enclosed in a weldment with a fan and heat exchanger at the bottom. The gas to be included in the analysis is air. I have made trial assemblies of the outer structure alone and Flow Sim does create a fluid volume, added the first gimbal structure which originally would not create a fluid volume but miraculously did the second time I ran Check Geometry. Now adding the the second gimbal structure, the Check Geometry will not create a fluid volume and the Invalid Contacts does not high-light the problem areas that I can see. These inner structures do have small gaps, but the first did eventually allow a fluid volume to be defined. Any ideas?
        • Re: Problem with fluid volume definition
          Bill McEachern
          Bad contacts. I have had it once in 11 years where flow did not ID the offending invalid contacts. So it is not bullet proof. Try looking at areas where you have hi order geometry. Try the solid works interference detection tool with the treat coincidence as interference flag switched on. Essentially SWX can not do the boolean op to get the fluid volume. It would get the dreaded "zero thickness geometry error". Take a look in the model and just figure it out. Try simplifying it and then complicating it to narrow down the search to some specific assembly. It is just work and no other flow code could miraculously sort it out either - you would have to do the boolean on your own to get the fluid volume. This is a CAD reality issue - nothing to do with the fluid code really.