Abstract: The permeability characteristics and tensile strength of a porous material developed from stainless-steel corduroy wire cloth for use in transpiration-cooled walls where the primary stresses are in one direction were investigated. The results of this investigation are presented and compared with similar results obtained with porous sintered metal compacts. A much wider range of permeabilities is obtainable with the wire cloth than with the porous metal compacts considered and the ultimate tensile strength in the direction of the primary stresses for porous materials produced from three mesh sizes of wire cloth are from two to three times the ultimate tensile strengths of the porous metal compacts.

Abstract: Cooling data from this experimental afterburner are successfully correlated over a range of Reynolds number based on the distance downstream of the leading edge of the porous wall. Calculations based on the correlation indicate that the combustion-chamber cooling-air requirements for an exhaust-gas temperature of 3700° R are only 16 percent of the air required for conventional forced-convection cooling. The cooling-air requirements were nearly independent of flight condition, but close control of cooling-air pressure is required at high flight speeds.

A low-speed investigatio was made in the Langley stability tunnel to determine the directional stability characteristics of tandem nonoverlap-type helicopter fuselages without rotors. The investigation consisted of a study of both bent and straight fuselages having either circular or essentially elliptical cross sections and with two vertical-tail sizes.