A project funded by the German Research Foundation (DFG) entitled „Leistungssteigerung von Strömungsmaschinen durch aktive Sekundärströmungsbeeinflussung in einer Verdichterstufe“ is carried out at the High Speed Cascade Wind Tunnel. In it active flow control for secondary flow minimization is investigated. The Project is set up as cooperation of the German Aerospace Center with the Technical University of Berlin. The experimental investigations are carried out at the DLR, the numerical part is done at the Institute of Fluid Dynamics and Technical Acoustics of the TU Berlin. The aim of the project is to enhance the performance of axial compressors by active means of secondary flow control. The flow characteristics of the three dimensional flow especially at the corner of vane and wall is determined in detail in order to achieve best locations and geometries for suction orifices.
Suction of the side wall boundary layer has an influence on the structure and shape of the secondary flow vortices (horseshoe, passage and corner vortex). In order to achieve a better aerodynamic behaviour, the secondary system is decreased in size and strength by the flow suction.