A TRANSIENT INFRARED TECHNIQUE FOR MEASURING SURFACE AND ENDWALL HEAT TRANSFER IN A TRANSONIC TURBINE CASCADE

摘要

This paper describes a method for obtaining surface and endwall heat transfer in an uncooled transonic cascade facility using infrared thermography measurements. Midspan heat transfer coefficient results are first presented for an engine representative first stage nozzle guide vane at exit Mach number of 0.77, Reynolds number of 1.05xl06 and freestream turbulence intensity of 16%. The results obtained from infrared thermography are compared with previously published results using thin film gauges in the same facility on the same geometry. There is generally good agreement between the two measurement techniques in both trend and overall level of heat transfer coefficient over the vane surface. Stanton number contours are then presented for a blade endwall at exit Mach number of 0.88, Reynolds number of 1.70xl06 and freestream turbulence intensity of 8%. Infrared thermography results are qualitatively compared with results from a published work obtained with liquid crystals at similar flow conditions. Results are qualitatively in agreement.