3 Replies Latest reply on Apr 29, 2016 12:44 PM by Amit Katz

    Induction heating in a conjugate heat transfer problem!

    Mohamed Abdelaziz

      Hello all

      I am working on a conjugate heat transfer problem with a hollow cylinder with the following details:

      1- The inner surface of the cylinder is heated by induction;

      2- The outer surface is surrounded by a a metallic block which contains some channels for water flow for purposes of cooling the outer surface.

      My questions are:

      1- What is the best way to represent the induction heating in simulation ( Heat generation rate or heat flux or whatsoever...)

      2- The contact between the cylinder outer surface and the cooling block, how can be dealt!

       

      Thanks in advance

      Mohamed 

        • Re: Induction heating in a conjugate heat transfer problem!
          Amit Katz

          1- The answer to this question depends on the physical phenomenon of the induction heating process. Do you have any more details about this process to give us?

           

          2- I would start the model with an ideal situation, where you have perfect surface contact with the two material. This is the simplest model, just you create your CAD geometry with the two parts sharing the same dimensions at this contact. In reality of course this will not be so nice, you will either have a metal to metal contact with it's associated thermal resistance, or you can use a thermal interface (such as the paste used for heatsinks) which you can model as a contact resistance in the software.

            • Re: Induction heating in a conjugate heat transfer problem!
              Mohamed Abdelaziz

              Thanks Amit for your advice with the contact issue.

               

              With respect to the induction heating process:

              1- The heating element (coil) which is made of a conductive material (as copper) will be inserted inside the hollow cylinder;

              2- As the current starts flowing inside the coil, a magnetic field will be developed inside and around the coil. When using an alternating current the coil will produce a magnetic field which changes its direction at the same rate of the frequency of the alternating current. When a conductive material is placed within the range of the alternating magnetic field, a voltage will induce in the work-piece; this voltage will results in a flow of electrons (current) which also changing its direction. The resistance of the workpiece to the flow of the electrons will develop the heat .

               

              This is just a quick and simplified idea about the physics of induction heating; I do not like to make coupling between the magnetic and thermal parameters in my simulation. The induction system has a certain power output for example 20 KW, I would like only to represent this value of power in the simulation. I have tried the "heat source" option for the cylinder internal surface with a heat generation rate of 20 KW. Do you think this is sufficient or a right way of representation!

               

              Mohamed