The Efficiencies of Single-Stage Centrifugal Compressors for Aircraft Applications

The thrust of most recent advances in single– and two–stage centrifugal compressor technology by the aerospace community has been motivated by interest in increasing airbreathing propulsion system power density, and improving specific fuel consumption with higher stage pressure ratios. Advances in the last decade have made it appropriate to review the major design parameters influencing the efficiency levels of single–stage centrifugal compressors for aircraft applications. A simple efficiency correlation was derived for advanced single–stage centrifugal compressors. It was based upon four critical parameters: • Inlet Specific Speed • Impeller Tip Diameter • Inducer Tip Relative Mach Number • Exit Discharge Mach Number The correlation was shown to predict attainable state–of–the–art efficiencies within a band width of ± 2 % points. This was considered acceptable for preliminary compressor and engine design work.