7 Replies Latest reply on Dec 24, 2010 4:24 PM by Anthony Botting

    Flow Simulation Boundary Conditions

      I am currently running SolidWorks Premium 2009 with Flow Simulation 2009.


      In SolidWorks Flow Simulation, I am trying to create boundary conditions such that I can run an internal flow analysis. However, when I click on the face of the lid I am trying to set the boundary condition, I come up with the error:


      Face<1>@DESCRIPTION is not laying on the boundary between solid and fluid region.


      I have tried on both sides of the lid as well as ensure I have no leaks in my system. On top of that, i have tried going through fluid subdomains to try and resolve the issue but no success. I have used this for other assemblies before but this is the first time I have encountered this error.


      My assembly has two flow inlets and outlets which are independant of eachother. I used the fluid volume check but it still comes up as zero and regardless of which lid face I select, I still come up with that error. Also, a weird thing is that Solidworks creates a computational domain around my WHOLE assembly as opposed to the part where I am trying to analyze and I can't seem to figure out why.

        • Re: Flow Simulation Boundary Conditions
          Anthony Botting

          Hi Jacob. You may  have run into a bug. Please let me know Service Pack number and if it's 32-bit or x64 edition AND what operating system you are using (all of these variables have played a factor in the past). In the mean time, it has helped me in the past to use the "Check Geometry" tool, and select option  "Create fluid body assembly" - if it allows you to, and take a look at the "fluid" with section views. I have found interesting leaks in the past. But as you say, you have done this before successfully so I can attempt to see if there' s a bug fix for that if you give me the SP number and other info. - Tony

          • Re: Flow Simulation Boundary Conditions
            David Paulson



            I often have the same issue with SW 2009 and Flow 2009, especially with sheet metal parts that have thin walls, and bend relief.  The solution for my issue is to create the Flow simulation in a part that resembles the geometry of the assembly, and with thicker walls so that it meshes easier.  The results are the same and faster.  It just takes the extra time to create the representative part.

            • Re: Flow Simulation Boundary Conditions
              Joe Galliera

              100% sure you have something wrong with the geometry.  It doesn't allow you to define a boundary condition because there is no fluid volume.  It may not have to do with the lids, it may have to do with the way that parts are in contact with one another in the assembly, eg. can't have a zero-area contact such as when two cylinders are adjacent.  You can contact your VAR to help you out with this issue, they should have someone on staff that knows what to do; where are you located?


              In versions 2010 and on, there is better handling of automatically resolving some of these issues.  If you attach the geometry, one of us can open it in a newer version to see if it resolved itself.

                • Re: Flow Simulation Boundary Conditions

                  Partially it was due to the geometry.  I fixed up portions of the assembly and have a fluid volume reading.  I still believe part of it might have to do with a bug in the service pack or program because there are configurations where I get some form of reading but then when i go to recalculate, the fluid volume completely disappears.


                  It's not that I wouldn't like to attach the geometry for assistance, it is that I cannot disclose the geometry due to policy.  I do appreciate your help in trying to answer my Solidworks issue.