Local convective heat exchanges from a rotor facing a stator

The local convective heat transfer from a rotor with a 310 mm outer radius is studied experimentally at a distance of 3 mm from a coaxial crown shaped stator with a 176 mm inner radius and a 284 mm outer radius. The experimental technique is based on the use of a thermally thick rotor heated from behind by infrared radiation. The local heat flux distribution from the rotor surface is identified by resolving the Laplace equation by finite difference method using the experimental temperature distribution as boundary conditions. The tests are carried out with the single rotor and the stator/rotor system for focal rotational Reynolds numbers ranging from 2.0.10(4) to 1.47.10(6) and thus sweeping across the laminar, transition and turbulent flow regimes. The local and mean Nusselt numbers for the single disc are compared with those obtained experimentally for the stator/rotor system. The flow structure in the space between the rotor and the stater is analysed by Particule Image Velocimetry. (C) 2000 Editions scientifiques et medicales Elsevier SAS.