Heat-Flux and Pressure Measurements and Comparison With Prediction for a Low-Aspect-Ratio Turbine Stage

This paper describes the detailed measurement of heat-flux distributions for the nozzle guide vane (NGV) airfoil, the NGV hub and tip end walls, and the blade for the Garrett low-aspect-ratio turbine (LART) stage. A shock tube was used to generate a short-duration source of heated air and thin-film gages were used to obtain detailed heat-flux measurements. In addition to the heat-flux measurements, surface-pressure measurements were obtained on the vane pressure and suction surfaces and on the hub and tip endwalls. These pressure measurements are shown to compare favorably with those taken at the same locations but in a long-run time facility. The time-averaged heat-flux data were obtained by sampling the gage signals at a frequency of 20 kHz/channel and then averaging the output over the test time of the experiment. The results are presented as a function of location within the stage and are compared with the results of a local flat-plate prediction technique.