Composite blade with partial length spar

摘要

A composite axial flow rotary machine blade (50) and method of blade construction is disclosed. A partial-length, spanwisely-disposed hollow spar (20) partially captures a shaped foam core (30) which extends from within the spar's cavity (26) along a substantial length of the blade (50) in a spanwise fashion. A resin-impregnated high strength, high modulus cloth (34) and graphite (32) composition overlays the spar-core assembly (36) and forms the casing (50) with airfoil regions (52, 54) of the propeller blade (10). This construction results in a rotor blade (50) with enhanced natural frequencies thereby providing for an enhanced operational speed range.