Effects of Leading Edge Film-Cooling and Surface Roughness on the Downstream Film-Cooling Along a Transonic Turbine Blade for Low and High Free- Stream Turbulence

摘要

This report is the culmination of a two year effort to demonstrate the capability for performing near wall high resolution Time Resolved Particle Image Velocimetry (TRDPIV) measurements in a transonic turbine. Performing TRDPIV in high speed wall bounded flows with high resolution/magnification often posses significant difficulties. For this reason, two preliminary studies where conducted in order to further understand the challenges that would be present in this type of environment. Hardware and algorithm advancements and developments ultimately enabled performing TRDPIV in the transonic cascade facility. However, high pressure, high speed and the turbine blade complex geometries (high curvature and acceleration) significantly inhibit our ability to deliver homogeneous distribution of flow tracers, especially in the near wall region resulting in low quality measurements and regions with randomly missing data. In addition to our experimental results this effort delivers a novel advanced data reconstruction methodology based on proper orthogonal decomposition that was developed to overcome the aforementioned limitation. The following report documents in detail the methods and results generated throughout this effort.