SURFACE HEAT TRANSFER VISUALIZATION ON A MODEL GAS TURBINE BLADE USING A TRANSIENT LIQUID CRYSTAL IMAGE TECHNIQUE
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
A transient liquid crystal technique has been developed to visualize the convective heat transfer coefficient distributions on a model gas turbine blade. A five-blade linear cascade is installed into a low-speed wind tunnel to simulate the gas turbine blade cascade. A color image processing system is used to measure the color change of the liquid crystal layer coated on the middle test blade at the center of the cascade. Detailed heat transfer coefficient distributions on a turbine blade are presented for the different flow Reynolds numbers. The cascade exit flow Reynolds number of the flow passing the cascade based on the blade chord is varied from 7.1 105 to 1.02 106. Results are compared with those obtained with the thin-foil thermocouple method under the same conditions. It is found that the transient liquid crystal image technique gives more detailed information than the classic thin-foil thermocouple method. Some findings with this technique, such as separation bubble effect on heat transfer coefficient on the pressure surface of the blade, flow transition location, and high heat transfer coefficients near the trailing edges on both the suction and the pressure surfaces of the blade, are an improvement over the classic method. The detailed information obtained using this technique may significantly influence the cooling design of the gas turbine blade. Copyright 1996 by Begell House, Inc.
