Experimental and Numerical Investigation of Second-Generation, Controlled-Diffusion, Compressor Blades in Cascade

摘要

This thesis contains a detailed experimental and numerical investigation ofsecond-generation, controlled-diffusion, compressor-stator blades at an off-design inlet-flow angle of 39%5c Investigation of the blades took place in a low-speed cascade wind tunnel using various experimental procedures. The objective of the wind tunnel study was to characterize the flow field in and around the blades at the off-design angle, and to investigate flow separation near the mid-chord for a high Reynolds number of 640,000. Rake probe survey's were performed upstream and downstream of the blades in order to obtain spanwise total pressure profiles. Surface flow visualization was performed on the blades using a titanium dioxide and kerosene mixture. Blade surface pressure measurements were obtained using a 40-hole instrumented blade from which coefficients of pressure were calculated. A standard optics, two-component, laser-Doppler velocimeter was used to characterize the flow field upstream, in the boundary layer on the suction side of the blades, and in the wake region. A numerical investigation was conducted using the rotor viscous code 3-D developed by Dr. Roderick Chima of NASA Lewis Research Center. Overall, good agreement between flow visualization, blade pressure measurements, laser measurements, and numerical modeling was obtained.