Experimental investigation of subsonic and transonic flows through a linear turbine cascade

Abstract

Experimental investigations of high subsonic and transonic flows through a linear cascade consists of VKI LS-59 blades have been carried out. Emphasis was put on analysis of the flow characteristics at the cascade exit. Experiments reported the static pressure measurements on blade surface, flow field survey downstream the cascade by means of Particle Image Velocimetry (PIV) and visualization by means of the Schlieren method. The turbulent intensity measurements have been performed at the cascade inlet to provide inlet conditions for numerical studies. The measurements have been carried out at two isentropic Mach numbers: M2,is=0.777 (high subsonic) and M2,is=0.975 (transonic). The corresponding Reynolds numbers based on the chord length and isentropic downstream velocity were equal to Re2,is=6.21⋅105 and Re2,is=6.82⋅105, respectively. The numerical simulations with Transition SST model have been performed to complement experiments and to verify applicability of data for testing and development of turbulence models. The RANS-based transition model reproduced correct isentropic Mach number profiles on the blade surface but underpredicted the turbulent mixing in the wake flow.