Laminar Heat Transfer and Pressure Drop In The Axial Circular Ducts of The Rotor of An Electrical Machine

摘要

Experimental results have been obtained on pressure drop and heat transfer for laminar flow of air in an axially cooled rough circular duct of a rotor of an electrical machine, with circumferential variation of heat flux. The entry conditions, and the range of parameters covered, simulate the real conditions more closely than in the work reported in literature. The local and mean heat transfer characteristics are evaluated and their variation with rotational Grashof number and aspect ratio are reported. The influence of rotation on hydraulic friction factor is studied.