2 Replies Latest reply on Feb 13, 2012 5:42 PM by Marco Laudisio

    Contra-rotating propeller simulation

    Marco Laudisio

      Hello there,

       

      I have a question about a ducted contra-rotating propeller in Solidworks 2011 Flow simulation.

       

      I 'm a beginner, and i'd like to evaluate the effect (on the flaps) of contra-rotating propeller position along the wing of a concept design aircraft. Using contra-rotating we hope to achieve an purely axial flow

       

      Propellers are buried in the wing. Will have crazy drag interferences, i know...

       

      In previous, similar Solidworks analysis i performed, i used to include in the analysis the complete 3d model of the propeller, then create a rotating region around propeller and so on.

       

      This time, i have not the real propeller model, it is under development, so i would to perform an analysis simulating it just like an actuator disk, knowing its dimensions, and design requirements as power, thrust, so its velocity drop. I don't need anymore. And we are talking about a contra-rotating prop, so no rotational flow is needed to be simulated.

       

      THE PROBLEM:                                                                      

      I modeled my wing/duct assembly but....i was not able to assign flow mass inlet and velocity outlet boundary conditions to propeller duct front and rear faces. I used, in the past, Fluent and i remember i made volume domain subtractions, so i always had faces to apply b.c.

      Now i have just solid part (wing and duct) faces, and seems that Solidwarks don't let me to create isolated surfaces to apply b.cs, i can just choose existing solid faces and i understand it, i have to put conditions on some domain connected elements. But if i model a volume contained in the fan, just to apply bc's, it won't work because i can't deactivate such solid without loosing bc's applied on it.

       

      I will appreciate a lot if anyone can help me.

       

      Than You in advance,

       

      Marco

        • Re: Contra-rotating propeller simulation
          Rich Bayless

          Hello,

           

          Go ahead and add a lid (model a volume) at the centerline of each duct.  Do not disable the lid.  On the inlet face apply an 'Outlet' condition, such as 'Outlet Velocity'.  On the outlet face, apply an 'Inlet' condition, such as 'Inlet Velocity'.

           

          But if i model a volume contained in the fan, just to apply bc's,

           

          I modified your part using SW 2011, see attached.  Load Flow Sim and just run it, you'll see how it works.

           

          Rich.

            • Re: Contra-rotating propeller simulation
              Marco Laudisio

              Dear Rich,

               

              Thank you! And really thank you for spending your time with my question. So with such volume i can simulate an actuator disk, perfect. I already tried to put lids (not with an extruded solid, but using lid command) on each duct inlet face, but i got an error like "the face doesn't lie on the solid-fluid boundary"...May be it was because i did it wrong and there was any sort of interference between  lids and duct walls.

               

              Anyway, again, lot of thanks, it seems i can follows in this way (waiting for contra-rotatings ).

               

              Marco