Local convective heat exchanges and flow structure in a rotor-stator system

This work deals with an experimental study of the flow structure and the local convective exchanges in the air-gap of a rotor-stator system. The experimental technique uses infrared thermography to measure the surface temperatures of the rotor and the numerical solution of the steady state heat equation to determine the local heat transfer coefficients. The analysis of the flow structure between the rotor and the stator is obtained by PIV (Particle Image Velocimetry). Tests are carried out for rotational Reynolds numbers ranging from 5.87 x 10(4) to 1.76 x 10(5) and for gap ratios ranging from 0.01 to 0.17. Analysis of the experimental results has determined the influence of the rotational Reynolds number and the gap ratio on the flow structure and the convective exchanges in the gap between the rotor and the stator. Some correlations expressing the local Nusselt number as a function of the rotational Reynolds number and the gap ratio are proposed. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.