The NACA has conducted an investigation to determine the performance that can be obtained from a multistage axial-flow compressor based on airfoil research. A theory was developed; an eight-stage axial-flow compressor was designed, constructed, and tested.

An investigation has been conducted by the NACA to determine the design-performance characteristics of the NACA eight-stage axial-flow compressor and the effect of altitude on the performance. The compressor was tested at simulated altitudes of 50,000; 36,000; and 27,000 feet at rotor speeds corresponding to compressor Mach numbers of 0.80, 0.85, 0.90, and 0.95 wit varying air flow at each speed.

Charts are presented to show the pressure rise that is obtainable in an engine-cooling installation with a typical airfoil-type propeller-speed fan. The charts cover fans of the stator-rotor, rotor-stator, and rotor alone configurations, with blades incorporating both the highly cambered 65-series blower-blade sections and the conventional low-cambered airfoil sections. The effects of operation of a geared fan with rotational speeds limited by compressibility considerations and the effects of initial rotational inflow are indicated. Use of the charts to predict the pressure rise obtainable with any fan of the types considered is illustrated in a sample calculation.