3 Replies Latest reply on Apr 1, 2007 7:09 PM by Duncan Gravills

    Slow computational speed, Any suggestions Please?

    Duncan Gravills
    Duncan Gravills Mar 29, 2007 12:01 AM

      Hi, i have created a model in solidworks cosmos FloWorks andhave tried to run a few simulations. they have taken about 6 hoursof computation to complete 6 seconds of real time simulation, iwant to have a simulation 3 hours long showing a breadmaker goingthough its cycle of fermenting the dough and then baking it. Atthis speed it will take 450 days! i think one of the reasons forthe slow calculation is that the outer wall is less than 1mm thick(sheet mild steel) and the baking pan is only 1mm thick (deep drawnaluminum and these thin components are causing a very fine mesh tobe generated and so lots of cells. Can anyone tell me if i amcorrect in assuming this and offer any suggestions of ways toreduce the calculation time even if the accuracy of the simulationis compromised a bit (This is only for a university project sointegrity of results is not as important as demonstrating anunderstanding). thanks for reading, thanks for any help.

      Duncan

      • 753 Views
      • Categories: Flow Simulation, Simulation
      • Tags:
        • Slow computational speed, Any suggestions Please?
          Eric Ryan
          Eric Ryan Mar 29, 2007 3:35 PM (in response to Duncan Gravills)
          Hello Duncan,

          Can you take advantage of any symetry in the model? If the model is symetric you can reduce the size of the computational domain and apply symetry to its boundaries. I believe there is a tutorial that uses symetry that explains how to use it.

          Good Luck,

          Eric
          • Slow computational speed, Any suggestions Please?
            Seth Langston
            Seth Langston Mar 29, 2007 3:50 PM (in response to Duncan Gravills)
            To check if your mesh is too small you can show the mesh from the results section in the floworks model tree. Visually inspect the mesh and see if you have too many cells in areas that are not very important to your analysis. If this is the case then you can reduce the initial mesh settings by right clicking on "Input Data" in the model tree and selecting "Initial Mesh...". A screen should popup showing different mesh setttings. Near the bottom you can uncheck the automatic settings to allow you more control over your mesh. If you decrese the number of cells per x,y, and z then you will have a corser mesh that should not take as long to calculate. I believe that the initial mesh settings are based on the boundary conditions. So if your boundary conditions are very small compared to the computational area then your mesh could be much finer than you need.

            This could be detrimental to the accuracy of your analysis. To help the accuracy you can add mesh controls and increase the partial cell refinement. Also, for Floworks 2007, make sure that "Optimize thin walls resolution" is selected.

            Changing mesh setting can increase the amount of time and resources required to mesh the model but it can help speed up the calculation process.