DEVICE FOR REDUCING THE NOISE OF A GASEOUS JET

A device for reducing the noise emitted by a gaseous jet as it escapes from a pipe, particularly the noise of a propulsive jet of a jet powerplant such as a gas turbine jet propulsion engine, comprises a plurality of deflecting members distributed around the jet. These members are movable between inoperative positions, outside of the jet, to operative positions in which upstream-facing parts of the members penetrate into the jet. When operative each member thus acts in a scoop-like manner to deflect a fraction of the jet and give it an outwardly-directed transverse component of velocity to assist mixing with the surrounding air. In its upstream-facing part at least one of the deflecting members is equipped with means to inject, into the jet and in a direction possessing a component disposed transversely of the general direction of the jet, an auxiliary jet of pressurized auxiliary fluid.