Experimental Investigation of Boundary Layer Transition and Turbulence Structures on a Highly Loaded Compressor Cascade

Abstract

Detailed measurements have been performed on a compressor cascade in order to obtain information about the overall performance, the state of the boundary layer, and the topology of turbulent boundary layers. The analysis of profile pressure distributions and wake traverse measurements across the midspan section of the cascade blade provide information on the loss behaviour. Using surface-mounted hot-film gauges on the suction side of the measuring blade different transition phenomena have been investigated under the influence of various inlet flow conditions representative of engine operation. Extensive measurements with 3D-hot-sensor anemometry have been evaluated to show essential features of the turbulent boundary layer. The results point out the dependence of turbulence characteristics, e.g. turbulent kinetic energy distribution and Reynolds stresses, on the inlet flow conditions and the upstream boundary layer development. The influence of free-stream turbulence intensity is discussed and the non-isotropy of the Reynolds normal stresses is presented.