10 Replies Latest reply on Dec 20, 2013 9:00 AM by Jared Conway

    solidworks flow simulation problem

    Lingang Hao
    Lingang Hao Dec 11, 2013 10:02 PM

      Hi everyone,

       

      I am doing a thermal simulation these days, but the result seems abnormal, could anybody help me what's the problem is?

       

      the model is just like a cuboid, it will generae heat, external analysis, steady-state analysis, the initial and ambient condion of temperature is 85℃,then run the program, the result show some area the temperature is lower than 85℃, but i think all the area in the computational domain the temperature should be higher than 85℃.so what's the problem is?

      捕获.JPG

        • Re: solidworks flow simulation problem
          Avdhesh Chanwaria
          Avdhesh Chanwaria Dec 12, 2013 12:01 AM (in response to Lingang Hao)

          This may be due to temprature losses.

          Select the correct material and its properties.

          this could be useful i believe.

            • Re: solidworks flow simulation problem
              Lingang Hao
              Lingang Hao Dec 12, 2013 1:49 AM (in response to Avdhesh Chanwaria)

              Hi Avdhesh Chanwaria,

               

              Thanks for your quickly reply, I have choose several material from the database to try, it still not work, the temperature at the edge of the computional domain still blow 85℃.

               

              Other people also told me it maybe due to the wrong boundary condition then caused the temprature losses. because the boundary was not inclosed the model completely.  but I think my setting is right, for external analysis, set the temprature 85℃ at  initial and ambient condition at wizard is equivalently the temperature boudary condition was add to the outer space of computional domain. and the model is obviously inclosed by the computionnal domain.

               

              How do you think?

                • Re: solidworks flow simulation problem
                  Kyu-Hyung Kim
                  Kyu-Hyung Kim Dec 12, 2013 7:26 AM (in response to Lingang Hao)

                  Plz check....General Setting<Radiaiton Environment Temperature...

                   

                  May be radiation environment temperaure is 25℃

                   

                  Is it right?

                  • Re: solidworks flow simulation problem
                    Jared Conway
                    Jared Conway Dec 12, 2013 11:18 AM (in response to Lingang Hao)

                    i'd suggest posting the model. seems simple enough to take a look at.

                     

                    otherwise, please describe the full set of boundary conditions

                    • Re: solidworks flow simulation problem
                      David Hensel
                      David Hensel Employee Dec 12, 2013 1:28 PM (in response to Lingang Hao)

                      Please check your Initial Conditions: There is a "+" to expand "Solid Parameters, Initial solid temperature", this may be set to the default condition of 25°C.  If you use a preview plot while solving, does the solid start at 85°C then cool to 25°C in the corners?

                      initial conditions.png

                        • Re: solidworks flow simulation problem
                          Lingang Hao
                          Lingang Hao Dec 13, 2013 4:55 AM (in response to David Hensel)

                          Thanks for all you guys advices, finally, I have found the reason just as Kyu-Hyung Kim's said. My radiation environment temperaure is 25℃, when changed it to 85℃, the results became reasonable.

                          • Re: solidworks flow simulation problem
                            Lingang Hao
                            Lingang Hao Dec 17, 2013 7:00 AM (in response to David Hensel)

                            Hi David Hensel，

                             

                            I have rsolved this problem by Kyu-Hyung Kim's advice, but I do not know the reason caused this difference? could you explain  it by theory?

                              • Re: solidworks flow simulation problem
                                David Hensel
                                David Hensel Employee Dec 17, 2013 7:36 AM (in response to Lingang Hao)

                                If you go to Help -> SolidWorks Simulation -> Flow Simulation Technical Reference when Flow Simulation is added-on to SolidWorks, you can view a wealth of information regarding the implemenation and known limitations of many parts of Flow Simulation.

                                 

                                On Page 31: "Environmental and solar radiation can be applied to external and internal problems. In fact, the environment radiation is the non-directional energy flux generated by the walls of an imaginary huge "room" that surrounds the body. This flux has predefined radiation parameters."

                                 

                                If you view page 40 of the PDF, equation 4.11 shows the use of the environmental radiation temperature, this regards heat transfer to ambient, such as the energy dissipation characterized in your model.

                                 

                                Given the scale of your model, you are forcing the edges of the computational domain to hold a high temperature.  If this was a known value, it would be appropriate to set the environmental radiation temperature to 85°C. 

                                 

                                It might be beneficial if the radiation environment was automatically set to the initial ambient condition, if this is something you'd like to see you can always check for an existing Enhancement Request through the Customer Portal, or submit a new one.  If you need further assistance, I suggest you contact your VAR.