Application of Tomographic PIV in a Transonic Cascade

Abstract

The contribution describes the implementation of Tomographic PIV in order to measure the three dimensional corner flow in a highly loaded compressor cascade in a transonic cascade wind tunnel at Mach number M1=0.68. The flow is dominated by a corner vortex which is driven by the pitch-wise pressure gradient between pressure and suction side. The vortex causes a flow separation between the sidewall and the blade. Especially the high shear between the main passage flow and the corner vortex induces strong velocity fluctuations which are responsible for the majority of total pressure losses in a compressor cascade. Furthermore the corner separation leads to blockage effects which limit the mass flow capacity of the cascade.