Turbulent heat transfer measurements using liquid crystals

The transient method of measuring heat transfer coefficients that uses liquid crystals, since its beginnings in the early 1980s, has become one of the best ways of determining full surface distributions of heat transfer coefficient. The turbomachinery research group at Oxford has concentrated on the application of the method to numerous mechanical engineering thermal problems specific to the jet engine. The paper summarises some of the recent developments in the technique including the implementation of an elegant way of producing a change in the fluid temperature. Recent, high-density heat transfer coefficient measurements are discussed together with the advantages such resolution offers in terms of flow field interpretation. A means of integrating the measurements into finite element software for subsequent data analysis is presented. The paper should be of interest to engineers interested in using the most modern heat transfer measurement techniques in their research and development programmes. (C) 1999 Elsevier Science Inc. All rights reserved.