N.A.C.A. Cascade Data for the Blade Design of High-Performance Axial-Flow Compressors

Abstract

CI0 = blade lift coefficient referred to mean air M = Mach Number, ratio of velocity entering the cascade to the speed of sound MCTm = entering Mach Number at which sonic velocity is reached on the blade Mfb = entering Mach Number at which losses through the cascade suddenly increase P = local pressure coefficient over the blade Per. — pressure coefficient corresponding to sonic velocity for a particular entering Mach Number P2/P1 = static pressure ratio across the cascade Q = quantity flow, cu.ft. per sec. U = rotational velocity of rotor blade element, ft. per sec. (Fig. 1) Va — axial velocity, ft. per sec. (Fig. 1) W = velocity of air relative to rotor element, ft. per sec. (Fig. 1) a = angle of attack, angle between effective entering air * and blade chord line, deg. (3 = stagger angle, angle of effective entering air measured from axial direction, deg. (Fig. 1) 7) = adiabatic rotor efficiency 6 — effective angle through which air is turned relative to the rotor, deg. (Fig. 1) <T = solidity, blade chord divided by the gap between blades (Fig. 1)