High Efficiency Can Be Achieved in Small Size Transonic Compressor Rotors

Current compressor development for gas turbine engines below 500 hp indicates a promising future for axial-centrifugal compressors, particularly if the axial stage is transonic. This forecast assumes high efficiency for the axial stage even though compressor size is 5 in. dia or less. The Boeing Co. has demonstrated a 4.81 in. tip diameter rotor that develops 1.43 pressure ratio at 90% efficiency at airflow of 3.10 lb per sec. This proves that high efficiency can be achieved in a small transonic compressor. The design, performance, and analysis of this compressor are described here.