Flow Pattern Transition and Related Heat Transfer in an Annular Gap Around a Truncated Conical Rotor in a Cylinder

Viscous flows in a concentric annulus with rotating inner cylinder was characterized by Taylor-Couette flow. When the inner cylinder is replaced with a truncated conical rotor, the effect of imbalanced centrifugal force induces the meridional circulation flow with a single toroidal vortex. Under non-isothermal condition at cooling the rotor and heating the vessel wall, the flow pattern is drastically changed with the thermal conditions and the rotating speed. This paper describes the vortex flow-pattern transition and related heat transfer of the mixed convection in such a system. The temperature and flow field were visualized by means of thermo-sensitive liquid-crystal tracers. At the same time, the local heat transfer distributions on the cylindrical vessel wall were measured under a uniform heat flux by the electrically-conductive transparent film. Based on the experimental findings is described the interaction between the heat transfer and the thermal flow field during the unsteady mixed convection in the annular gap.