3 Replies Latest reply on Mar 19, 2008 6:18 PM by Fernando Cuenca

    Line and Point Heat Transfer

    Jason Strauch
      Hi All,

      No luck getting heat transfer across a line or point contact, even when changing contact sets and global contact. Simple 3 part study of real system that has a ball in between a conical indent (circular line contact) and a point contact on other side. Mates using split lines are coincident and fine on line side.

      Can make work using small surfaces (less than tet size), but not like true situation with rigid bodies. Also reallize tet FEA area is not true line or point, but...

      Thanks in advance, fun stuff

      Lab Enginerd
        • Line and Point Heat Transfer
          Basil Gello
          Jason,
          why not make the surface contact with a small surface areas instead? It will work.

          Regards, Basil
            • Line and Point Heat Transfer
              Jason Strauch
              Thanks Basil,
              That is what I have been doing, hence the reference to area contact geometry versus tetrahedron size. The thing is, I have done post test profilometer measurements to see if the contact area deformed enough to model, and it is orders of magnitude less than the 1/100 of a mm line area width in SW. The balls are Zirconia (1.2 mm dia) and resting against tantalum, so rigid body mechanics a very good approximation for those materials.

              It just looks like that is the limit of the Cosmos code and I can either write my own or use the results that match the experimental data.

              Thanks again,
              Jason
            • Line and Point Heat Transfer
              Fernando Cuenca
              Jason,
              Conduction is dependent on the area of contact. In theory a line or point contact has a contact area of zero and there is no heat transfered by means of conduction between the bodies, rigid or not. In reality the bodies are not contacting in a line, as you said, it is an approximation (one that in this case is not good for FEA), plus you may also have other means of heat transfer, convection or radiation. This is not a limit of Cosmos, it is the way heat transfer is, it is reflected in the heat transfer equations.