method of control design of intensity noise of jet wake.

摘要

912,293. Jet-propulsion nozzles. UNITED AIRCRAFT CORPORATION. July 29, 1959 [Aug. 1, 1958], No. 26074/59. Class 110 (3). In an aircraft having a jet-propulsion engine which produces a high-velocity non-pulsating propulsive gas flow, a jet noise suppressor comprises a duct having an inlet arranged to receive the propulsive gases from the engine and a discharge opening for discharging the gases to atmosphere, the duct being convergent immediately adjacent the discharge opening in a substantially horizontal plane and divergent immediately adjacent the opening in a substantially vertical plane. The gases from a gas turbine jet propulsion engine, Fig. 1, pass through a noise suppressor comprising a duct 20 having a circular inlet 28 and a discharge opening 22 formed as an elongated slot with its major axis vertical and in line with a strut supporting the engine from the aircraft wing. The opening 22 is defined by converging vertical side walls 50, 52 and by diverging top and bottom walls 54, 56. The effect of the divergence of the top and bottom walls may be increased by movable vanes mounted on a fixed vane located in the nozzle outlet. The discharge duct may be provided with stiffening vanes adjacent its discharge. Specifications 765,021, 777,572 and 879,481 are referred to.