Measurement and Analyses of Heat Flux Data in a Turbine Stage: Part II—Discussion of Results and Comparison With Predictions

Abstract

Parts I and II of this paper report the measurement and analysis of detailed heat flux distributions obtained on the nozzle guide vane (NGV), rotor, and shroud of the full-stage rotating turbine of the Garrett TFE 731-2 engine. Part I is devoted to a description of the experimental apparatus and the data analysis procedure. Part II is concerned with the experimental results and their comparison with predictions obtained using a flat-plate technique and with predictions obtained using STAN5. Measurements were performed for values of the ratio of wall temperature to total temperature equal to 0.21, 0.33, and 0.53. For the NGV airfoil and rotor blade, the influence of wall temperature ratio on the Stanton number is shown to be generally 10 percent or less. For the NGV airfoil, and the rotor blade pressure surface, the flat-plate turbulent-flow prediction provides a reasonably good comparison with the data. With the rotor operating, the state of the boundary layer generally appears to be turbulent for both the NGV airfoil and the rotor blade. Predictions obtained using STAN5 confirm that boundary layer transition occurs at a value of Reθ substantially less than 200.