Abstract: A vortex suppressing flow eductor apparatus having a vortex filament producing flow eductor is provided with corresponding vortex destroying plates positioned and extending sufficiently downstream from a point within educted flow and deep enough into the vortex filament so as to essentially destroy the vortex filament. A particular embodiment provides a freestream sensor scoop, for use in an aircraft gas turbine engine inlet, having an eductor diffusing channel and a fairing surrounding a forward portion of the diffusing channel. A sensor supporting mast is provided for helping to measure freestream air characteristics. Vortex destroying plates are provided for suppressing vortex filaments generated by the channel, fairing, and mast.

Abstract: A flade exhaust nozzle for a high thrust jet engine is configured to form an acoustic shield around the core engine exhaust flowstream while supplementing engine thrust during all flight conditions, particularly during takeoff. The flade airflow is converted from an annular 360.degree. flowstream to an arcuate flowstream extending around the lower half of the core engine exhaust flowstream so as to suppress exhaust noise directed at the surrounding community.

Abstract: A marine exhaust system is provided for separating the gas from the water of gas/water mixture produced by a marine engine, and expelling the gas a sufficient distance from the hull of a boat to place it outside of the turbulent boundary layer surrounding the hull and the low pressure area following behind the boat. A nozzle having a variable outlet area is mounted amidship on the hull for maintaining a predetermined pressure within the exhaust system in order to expel the gases a maximum distance from the boat. In addition, apparatus is provided for removing the water from the exhaust system prior to the gases reaching an acoustical chamber for attenuating exhaust gas noises.

Abstract: A marine exhaust system is provided for separating the gas from the water of gas/water mixture produced by a marine engine, and expelling the gas a sufficient distance from the hull of a boat to place it outside of the turbulent boundary layer surrounding the hull and the low pressure area following behind the boat. A nozzle having a variable outlet area is mounted anidship on the hull for maintaining a predetermined pressure within the exhaust system in order to expel the gases a maximum distance from the boat. In addition, apparatus are provided for removing the water from the exhaust system prior to the gases reaching an acoustical chamber for attenuating exhaust gas noises.

Abstract: The present invention comprises a cowling structure for a gas turbine aircraft engine which allows the aerodynamic characteristics of the inlet passageway to the engine to be varied in accordance with flight conditions. This structure includes an annular lip portion positioned at the front edge of the cowling defining an aerodynamically sharp contour and which is mounted on a set of support struts constructed for allowing the lip portion to be translated forwardly and backwardly from the forward edge of the cowling. The structure further comprises a mechanism for injecting pressurized air into the airflow along the trailing edges of these support struts in order to suppress turbulence induced in tha airflow such that noise as may be produced as a result of airflow is substantially decreased.

Abstract: According to the present invention, there is provided a jet engine comprising a cowl, an exhaust nozzle at the rear of the engine, a plurality of vanes that extend substantially circumferentially around the cowl of the engine in the region of the exhaust nozzle, means to support the vanes on the cowl so that the vanes can be moved between a retracted position in which they lie close to the cowl and an extended position in which they are spaced apart from the cowl so that, together with the cowl, the extended vanes define a substantially annular duct having an inlet and an outlet, one or more nozzles beneath each vane for directing high pressue air into the duct in a direction towards the rear of the engine, means for feeding high pressure air from the engine to the nozzles and an actuator arrangement for moving the vanes between the extended and retracted positions.

Abstract: This invention relates to a double-flow turboshaft engine with confluent nozzle, i.e. of the type having a central generator emitting via its outlet orifice a flow of hot gas and an annular bypass duct which surrounds the central generator and through which passes a bypass flow of relatively cold gas, the gas flows being freely confluent within the nozzle which extends the annular duct in convergent manner beyond the outlet orifice of the central generator, wherein it includes controlled means for momentarily varying on the periphery the passage of the flux of relatively cold gas in the annular bypass duct, with a view to compensating, at least partly, the degradation of the performances of the turboshaft engine when they are limited either by the maximum operational temperature of the central generator or by the maximum power of the engine, but not by these two conditions simultaneously.

Abstract: A jet engine nozzle operable in a cruise setting and a noise attenuation setting. In the cruise setting the nozzle provides simple through flow. In the noise attenuation setting some ambient flow is ducted into the through flow and some through flow is ducted into ambient flow. The nozzle comprises a fixed portion and a movable portion, rotatable a part of a revolution about the fixed portion. The nozzle comprises two rotary valves which operate in unison, a sleeve type valve and a face type. The sleeve type comprises cooperating lobed openings in the fixed portion and in a forward segment of the movable portion, the movable portion fitting telescopically over the fixed portion. The rotary type comprises the exit faces of aft facing lobes in the fixed portion and cooperating entrance faces of lobes in the aft segment of the movable portion. In the attenuation setting both valves are open.

Abstract: An ejector and method of reducing jet engine noise are disclosed wherein the primary combustion gas stream of the jet engine is ejected into a mixing section or zone of the ejector and into which a secondary gas stream is also injected at a velocity sufficient to create a choked or Mach 1.0 mixed flow condition, resulting in rapid mixing of the primary and secondary gas streams in the mixing zone. A diffuser is connected to the ejector downstream from the mixing zone for pulling the mixed gas stream through the mixing zone. The diffuser has an exit area greater than the area of the mixing zone. The ejector is provided with means for adjusting the area of the mixing section or zone and diffusion section to match engine operating conditions so as to create proper conditions within the mixing zone for noise suppression. Noise suppression by the method and means disclosed occurs at all frequencies with a minimal loss of thrust, and possibly a slight gain.

Abstract: A jet engine noise suppressor particularly adapted for supersonic aircraft. The nozzle (10) has an internal wall surface (70) around a generally centrally positioned body (50) and an annular area (62) extending between the wall and the body. In this area there are separate gas and air flow ducts (64, 66) having entrance ends (82, 80) and exit ends (76, 78), the entrance ends of the gas ducts extending annularly around the body (50) to receive gas exhaust from the engine and the air ducts have entrance ends annularly outwardly of the gas ducts along the wall (70). There are openings (26) in a wall (14) upstream of the ducts to supply ambient air to the entrance ends (80) of the air ducts. There are doors (20) and actuators (24) operable to open and close the openings (26).

Abstract: The invention is an aircraft jet engine variable shape, fluid flow nozzle (10) which is adjustable to sound-suppression (take-off) and nozzle open (cruise) modes. In the take-off or sound-suppression mode a plurality of movable flaps (24) are positioned inwardly by actuators (36) so as to form a fluted arrangement with a plurality of webs (13) that define the periphery of the nozzle (10) exit. A plurality of transverse fins (32) on the flaps (24) maintain a seal via a plurality of seals (34) with the web side walls (22). In the nozzle open or cruise mode of operation the guide vanes (26) of the flaps (24) are maintained in alignment with the outer walls of the webs (13) to form a maximum area-circular cross-section nozzle exit.

Abstract: A jet engine having its turbine section and exhaust nozzles particularly arranged to alleviate noise. There is a forward turbine section positioned in a first passageway to receive all or substantially all of the gaseous discharge from the combustion section of the jet engine. There are second and third coannular passageways positioned downstream of the first passageway, with the second passageway being positioned radially inwardly of the third passageway. A second turbine stage is positioned in the second inner passageway to receive a portion of the gaseous flow from the first passageway so as to be driven thereby, with the first portion of gaseous flow being discharged at a relatively low velocity at a radially inward location. A second portion of the gaseous flow passes from the first passageway to the third passageway and is discharged at a relatively high velocity in a generally annular pattern radially outward of the flow of the first portion of the gaseous flow.

Abstract: A method and apparatus for selectively generating a noise suppressing hot gas shield are described. A portion of the jet engine exhaust flow is selectively directed to a nozzle which at least partially surrounds the circumference of the jet engine exhaust. Prior to exiting the nozzle the flow is passed through a pressure, and therefore density, loss producing device to provide a shield flow of optimum noise suppression properties.

Abstract: A missile with an air breathing gas turbine propulsion engine configured with a translating exhaust plug nozzle to minimize longitudinal length of the engine section.