3 Replies Latest reply on Oct 14, 2014 7:51 PM by Jared Conway

    how to use steady-state mesh for transient study?

    Dan Hofstetter

      I need to generate a mesh from a steady-state simulation, then use that mesh for a transient study.  How can I do this?  I have successfully used the Transferred Boundary Condition under General Settings, but all this does is load the flow field - the mesh from the steady-state study with the local refinements does not get loaded (it should have ~2 million cells, but instead it is loading a default mesh with < 1 million cells that would be generated by default as new).  I have specified the .fld file that contains the correct number of mesh cells, but it doesn't seem to help.

       

      If there is no way to do this, I'll need to do my own local refinements with local initial meshes, but it would be really nice to be able to solve a steady-state calculation and let the solver identify regions with high gradients and automatically refine them for use in a transient study.

       

      Thanks!

        • Re: how to use steady-state mesh for transient study?
          Jared Conway

          Clone study

          copy mesh

          when running don't let it demesh

          enable transient

          disable mesh refinement

          transfer conditons

          run

           

          in in my head this should work

           

          but if you are running transient, will the solution adaptive mesh really be true to the transient solution if it was found for the steady state?

            • Re: how to use steady-state mesh for transient study?
              Dan Hofstetter

              Copy mesh - what files do I need?  Is it just the .cpt file, or do I need the other ones too?

               

              After thinking more about this, I really only want the mesh - I want the conditions to develop from time zero.  I think using the solution adaptive mesh is probably fine as long as the refinements are in the correct spatial regions.  It would be like running the simulation with a level 7 mesh everywhere, even if you only needed level 3 over 90% of the computational domain.

               

              I wound up creating seven local initial mesh regions based on what I saw in the solution adaptive mesh and running the simulation again.  I may try the mesh copying if I can get it to work and compare the solutions to see which better matches the physical measurements.