An experimental examination of the effect of trailing edge injection on the aerodynamic performance of gas turbine blades

Abstract

This thesis documents an experimental investigation into the effect of trailing edge Injection on the aerodynamic performance of turbine blades conducted at Virginia Polytechnic Institute and State University (VPl&SU). A brief description of the arrangement, instrumentation and data acquisition system of the VPl&SU Transonic Cascade Wind Tunnel is given. Testing was conducted under a number of test conditions. Baseline data was obtained for the blades with no trailing edge injection. The blades were then tested for two different blowing rates to test the effect of blowing rate on the total pressure loss coefficient, L. Tests were conducted at a variety of save cascade exit Mach numbers ranging from 0.79 to 1.36. Measurements were taken at three locations downstream of the cascade blade trailing edges. The algorithm used to calculate the L from the measured data is discussed. Results of the testing indicate that trailing edge injection has a negligible effect on the total pressure loss coefficient. Correlations of cascade exit Mach number to L are given. The development of L downstream of the blade trailing edge is discussed.