Comparison of Performance of Supersonic Blading in Cascade and in Compressor Rotors

Abstract

Reduction of engine weight and engine specific fuel consumption is a continuing goa of jet engine designers. An attractive approach is through the development of efficient, high-tip speed compressors operating with supersonic relative inlet Mach numbers. For these compressors, selection of highly efficient supersonic blading is required. Although the evaluation of new blade geometries can be obtained more conveniently from supersonic cascade tests rather than compressor, it has not yet been adequately established that good correspondence exists between cascade and compressor tests. The paper shows that such correspondence exists. In this paper performance of three airfoil shapes tested in cascade is briefly discussed and compared to the performance of similar airfoils tested in a rotor. A description of a supersonic tunnel is given and precautions necessary to obtain meaningful data are stressed. Good correspondence obtained between the cascade and rotor results is discussed.