Phase-Resolved Heat-Flux Measurements on the Blade of a Full-Scale Rotating Turbine

Abstract

This paper presents detailed phase-resolved heat-flux data obtained on the blade of a Teledyne 702 HP full-stage rotating turbine. A shock tube is used as a short-duration source of heated air and platinum thin-film gages are used to obtain the heat-flux measurements. Results are presented along the midspan at several locations on the blade suction and pressure surfaces from the stagnation point to near the trailing edge. For these measurements, the turbine was operating at the design flow function and at 100 percent corrected speed. Results are presented for the design vane/blade spacing (0.19 C s ) and at a wide spacing (0.50 C s ). Data are also presented illustrating the phase-resolved blade heat-flux distribution with upstream cold gas injection from discrete holes on the vane surface. The results illustrate that several successive passages can be superimposed upon each other and that a heat-flux pattern can be determined within the passage. A Fourier analysis of the heat-flux record reveals contributions from the fundamental and first harmonic of the passage cutting frequency. Time-resolved surface pressure data obtained on the blade pressure surface are compared with heat-flux data.