Design of a Small Axial Compressor for High Efficiency Over a Wide Operating Range

Abstract

Textron Lycoming’s advanced compressor design system has been used to design and develop a three-stage axial compressor in the small flow class (less than 10 pps). New and innovative aerodynamic and mechanical design features identified in recent technology programs were used to optimize efficiency and range in the present design. Specific areas of technology development in this research program are: customized rotor airfoil shapes for minimum shock loss, airfoil endwall loading selected to reduce losses, variable geometry design for large range and high efficiency compressor operating requirements, variable stator hub contours and attachment design for minimum clearance loss, flowpath sealing for low leakage flow, and reduced frictional pumping losses. Performance objectives were experimentally verified with extensive prototype rig testing where sufficient instrumentation was installed to identify overall and individual stage operating charactertistics. A complete description of the axial compressor aerodynamic design is presented; executed using meanline, axisymmetric and three-dimensional flow analysis. Elements of the mechanical design that impact overall performance potential were controlled in the design and are described. Mechanical integrity for rig development and engine operation were verified for all components of the design and are reviewed.