Experimental Characterization of Very High Turning Single and Tandem Compressor Profiles

The axial compressor front stages of the forthcoming aircraft engines architectures will operate at high subsonic inlet Mach number over a large range of incidence angles, while providing unprecedented turning levels. In this study, a single vane profile and a tandem vane configuration, designed for identical inlet flow conditions and for a design turning in the excess of 45 degrees, have been experimentally assessed in a linear cascade arrangement. The present paper outlines first the aerodynamic design philosophy for the tested profiles. Then, the design of the facility and of the test section are presented in view of the challenges imposed for the performance evaluation of very high turning compressor cascades at engine-like conditions. The instrumentation is also presented, and finally, the performance comparison of each blade configuration is given and put into perspective with the measurement uncertainty. The analysis of the blade sets performance aims to highlight the advantages and drawback of each configuration. The use of both the experimental data and CFD computations help to provide an insight into the loss driving mechanisms. This paper demonstrates that single profile blades and tandem configurations can be designed to provide identical performance close to the design incidence region of the loss bucket, with the latter outperforming at high positive and negative incidences despite a smaller solidity.