2 Replies Latest reply on Nov 21, 2015 9:10 AM by Per Mjörnstad

    Hi, i am trying to get the heat transfer coefficient off nozzles.

    Per Mjörnstad

      We are going to konstrukt nozzels for drying.

      We blows hot air to a wall,

      How can a get the heat transfer coeffecient right ?

      It seems that Solidworkt calculate the heat transfer coefficient from wall to air and not the opposit.

       

      Some data are:

       

      Pn=1000Pa

      T=100 degrees

      Tplate=24.6 degrees (konstant ?)

      Plate dim. 300x106x2mm

      Plate distance from nozzel 10mmNozzle.PNG

      The test nozzel is 53mm with, 300mm length and the slot is 2mm

      My result in solidworks get the heat transfer coefficient about 100  [W/m^2/K]

      Teoretic:   coefficient about 300  [W/m^2/K]

      And in labb  coefficient about 300  [W/m^2/K]

       

       

       

      Hope you  can help me .

       

      //Per

        • Re: Hi, i am trying to get the heat transfer coefficient off nozzles.
          Amit Katz

          You have the wall set at a constant temperature by your boundary conditions (Heat Source\VS Temperature 1), so by definition the wall will always be at this temperature and you may as well not even blow any air on it.

           

          If your goal is to find the equilibrium temperature of the wall, then remove the heat source on the wall. You can set the initial temperature from the project settings (default setting is 20C for all solids and fluids I believe.)

           

          By the way, this model is just the wall just floating in air. Is this really how you want to simulate it? You will have heat transfer to the wall on all sides as the air from the nozzle is blow on and around the wall.

            • Re: Hi, i am trying to get the heat transfer coefficient off nozzles.
              Per Mjörnstad

              Hello Amit

               

              Thank you for testing my modell.

              I' m not intresting in the temperature off the wall att all.

              Just the heat transfer coefficient (how effective different nozzels design).

              If you check the xy Plot 1 you should get this result se picture. but it should be higer like 300  [W/m^2/K]

              In teoret and practical tests.

               

              It seems that Solidworkt calculate the heat transfer coefficient from wall to air and not the opposit that i want see. formula.

               

              Formel.PNG

               

               

              Heat transfer coefficient.PNG

               

              Best Regards

               

              //Per