Investigation of Aerodynamic Profile Losses for a Low-Reaction Steam Turbine Blade

Abstract

This thesis presents the results of a linear cascade experiment performed on the mean-line and near-tip sections of a low-reaction steam turbine blade and compares them to CFD of the former. The purpose of these tests was the refinement of a proprietary empirical profile loss model. A review of the literature shows that experimental data on this type of blade is not openly available. The continued efficacy of empirical loss models to low-reaction steam turbine blades requires data from experiments such as the present study. Tests covered a range of incidence from -6 to +4 and exit Mach numbers from 0.4 to 0.6. Extensive static pressure taps on the blades allowed detailed examinations of blade loading. This loading was dissimilar to steam turbine blade loading in the open literature. A traversing five-hole probe measured conditions downstream of the blade row to enable the calculation of a total pressure loss coefficient. The area-averaged total pressure loss coefficient for both profiles was near 0.08 and was not sensitive to incidence or exit Mach number over the ranges tested.