Spiral Tube

A frequently occurring geometry for heat exchangers is that of a long tube wound into a helix or spiral around a core volume. There is to be heat exchange between the tube and the gases (or solids) in the core. However, the length scales of these two parts of the geometry are very different, thus complicating the interface between the tube and the core processes. the tube is too long for direct numerical modeling. Therefore, in the present work, we use an axis-symmetric numerical model of the core and link it to analytical equations for the tube. In this way, radial boundary conditions at the core perimeter become the driving force for the thermal process in the tube; at the same time, the results of the analytical integration in the tube provide boundary conditions for the core. Also, it is shown that there is enhanced convective heat transfer in the curved tubes, compared to straight tubes.