Design of a High Efficiency Compact Centrifugal Compressor for Rotorcraft Applications

Current and envisaged future airport congestion levels motivate the need for increased use of high-performance rotorcraft and rotary wing aircraft. The turboshaft engines that power these aircraft must have high power density, fuel efficiency, and wide operability. The lower physical flows associated with turboshaft engines for rotorcraft, and the high overall pressure ratios (OPRs) required for performance, motivate the use of centrifugal compressors as the last stage of compression. This paper describes the design of a high efficiency, compact centrifugal stage scaled for use as a measurement test bed that is representative of a state of the art compressor stage in rotorcraft engines. In addition to the design activity, this paper outlines the development of the rig instrumentation layout through inspection of CFD results. The instrumentation layout contains high density static and dynamic pressure measurements, to be used for validating design and analysis tools, and for acquiring physics insight to enhance centrifugal compressor design and performance capability. The fabrication of this stage is underway for initial test entry in 2011.