Aerodynamic Measurements in a Linear Turbine Blade Passage With Three-Dimensional Endwall Contouring

Abstract

Secondary flows created in the turbine blade passage contribute to greater pressure losses and increase the thermal loading on the endwall. The present paper explores the concept of utilizing a three-dimensional endwall for weakening the secondary flows in a low speed linear turbine blade cascade. The endwall contour is designed to reduce the near-wall cross-passage pressure gradient that drives the crossflow. Measurements undertaken include smoke flow visualization, velocity and turbulence data using a hot wire anemometer, velocity and pressure measurements using a five-hole pressure probe, and surface static pressures measurements. The measured data indicate that the endwall contour reduces the mass averaged pressure losses across the blade passage by over 30%. Endwall contouring also produces a much more uniform exit flow field.