AERODYNAMIC PERFORMANCE OF A VERY HIGH LIFT LOW PRESSURE TURBINE AIRFOIL (T106C) AT LOW REYNOLDS AND HIGH MACH NUMBER WITH EFFECT OF FREE STREAM TURBULENCE INTENSITY

摘要

A detailed experimental analysis of the effects of the Reynolds number and free-stream turbulence intensity on the aerodynamic performance of a very high-lift, mid-loaded low-pressure turbine blade (T106C) is presented in this paper. The study was carried out on a large scale linear cascade in the VKI S1/C high-speed wind tunnel, operating at high exit Mach number (0.65) with a range of low Reynolds numbers (80,000 - 160,000) and three levels of free-stream turbulence intensity (0.8 - 3.2%). In the first part of the paper, the overall aerodynamic performance of the airfoil is presented, based on mid-span measurements performed by means of static pressure taps, hot-film sensors and a 5-hole probe traversing downstream of the cascade. Some specific features of separated flow transition are also discussed for selected cases. The second part presents the analysis of the results in terms of correlations derived for the characteristic points of boundary layer separation and transition. A comparison with some previously published prediction models is shown. The large variety of boundary conditions provides a unique database for validating codes dealing with separated flow transition in turbomachinery.