Comparison of the capability of active and passive methods of boundary layer control on a low pressure turbine cascade

Abstract

This paper contains results of measurements conducted at the High-Speed Cascade Wind Tunnel of the University of the German Armed Forced in Munich, Germany, on a low pressure turbine cascade provided with several techniques of boundary layer control. Two types of passive turbulators consisting of a roughened surface and a backward facing step are compared with an active blowing on the profile suction side concerning their influences on the profile pressure distribution and the two dimensional losses in the midspan area. Data on the cascade performance are presented for steady and periodically unsteady inflow at various Reynolds numbers with a special focus on the low Reynolds number band. © 2010 Springer-Verlag Berlin Heidelberg.