Analysis of the Tip Leakage Flow Field in an Axial Turbine

摘要

Comparisons of experimental laser-Doppler-velocimetry measurements using the Naval Postgraduate School cold-flow turbine test rig were made with 3D viscous computational fluid dynamics flow solutions. The turbine tested was the first stage of the Pratt and Whitney designed High Pressure Fuel Turbopump for the Space Shuttle Main Engine. The laser anemometer was modified to incorporate a field stop, which acted as a spatial filter to limit reception of undesired blade reflections. The laser measurements were made in the endwall region of the test turbine, at three axial locations, and at three radial depths. For each location, absolute flow angle, axial and tangential velocity ratios, turbulence intensities and correlation coefficients were measured. The computational effort encompassed modeling a single blade passage of both the stator and the rotor and computing flow solutions of the stage using NASA software. Exit plane and endwall flow property profiles showed good agreement when compared with experimental data.