Abstract: A technique for producing thrust by generating a hybrid plume plasma exhaust is disclosed. A plasma flow is generated and introduced into a nozzle which features one or more inlets positioned to direct a flow of neutral gas about the interior of the nozzle. When such a neutral gas flow is combined with the plasma flow within the nozzle, a hybrid plume is constructed including a flow of hot plasma along the center of the nozzle surrounded by a generally annular flow of neutral gas, with an annular transition region between the pure plasma and the neutral gas. The temperature of the outer gas layer is below that of the pure plasma and generally separates the pure plasma from the interior surfaces of the nozzle. The neutral gas flow both insulates the nozzle walls from the high temperatures of the plasma flow and adds to the mass flow rate of the hybrid exhaust. The rate of flow of neutral gas into the interior of the nozzle may be selectively adjusted to control the thrust and specific impulse of the device.

Abstract: Successful flight of high altitude military aircraft is dependent, in part, pon the ability of the aircraft to remain undetected during flight. Against the highly sophisticated infrared sensors developed during recent years, particularly for miliary use, an aircraft powered by a gas turbine engine is at a particular disadvantage. Hence infrared emissions from gas turbine engines have been reduced by use of a variety of infrared radiation (IR) suppressor designs. But in these designs aerodynamic problems are difficult to analyze and geometrical parameters are very critical, and nearly impossible to maintain. The IR suppressor herein provides the best blend of simple aerodynamics, heat transfer, and geometry.

Abstract: A cooling system for providing a layer of relatively cool gas (28) adjacent the surface of a duct (24) carrying a flow of relatively hot gas (22) includes an elongated louver nozzle (32), an elongated plenum (40) and one or more crosswise dividers (42) for separating the plenum and nozzle into a plurality of individual segments (40, 40a; 32, 32a) having sized supply orifices (44, 44a) disposed therein.

Abstract: A method of suppressing the formation of contrails from the exhaust of an engine including the steps of providing a solution of a non-corrosive surfactant in a combined carrier and nucleating agent selected from the group of water soluble monohydric, dihydric, trihydric or other polyhydric alcohols, forming the solution into a vapor, and injecting the solution into the exhaust of the engine. The solution may include by weight between about 0.01% to 2.5% of the non-corrosive surfactant, between about 1% and 8% water, and between about 85% and 99% ethylene glycol. Another solution may include by weight a monohydric, dihydric or polyhydric alcohol in an amount of between about 85% and 99% and the non-corrosive surfactant in an amount of between about 0.01% and 8%. Still another solution may include an inorganic nucleating or hygroscopic salt, such as ammonium iodide, ammonium fluoride, silver iodide or calcium chloride in monohydric, dihydric or polyhydric alcohols and surfactant mixtures.

Abstract: The cooling air for the nozzle of an augmentor of a gas turbine engine is maintained uniformly around the circumference to assure the prevention of hot streaks that would be occasioned by the liner "sagging". A separate end piece having judiciously located gaps for directing air over the nozzles, flaps and seals attached to the end of the augmentor duct maintains concentricity during augmentor operation, and affords support to the liner of the duct.

Abstract: A support and seal assembly for attaching porous metal transition duct liner segments to a transition duct of a gas turbine engine. The assembly includes an elongated retainer attached to the duct and separated therefrom to define a retention space therebetween. Panel supports are rigidly attached to adjacent ones of the liner segments and extend perpendicular to adjacent side edges of the liner segments. Distal ends of the panel supports project into the retention space from opposite sides of the retainer and are captured in the retention space to attach the liner segments to the duct. A pair of resilient sealing strips are mounted on the retainer and include sealing nodes which are self-biased against respective ones of the liner segments along the side edges thereof to seal the gap between the adjacent liner segments.

Abstract: The assembly comprises a collector nozzle which is fixed to a turbine engine and which is elbowed laterally towards the exterior and which debouches into injection nozzles which are also elbowed and which open into a mixer masked laterally by means of a fairing, of which a shaped forward section defines, with an internal shaped screen and a central plug, a semi dynamic principal air inlet. The aspirated air dilutes the gas in the mixer which is terminated by means of an elbow directed upwardly and which can pivot about a transverse axis. In the position of maximum deviation upwardly this elbow masks the hot parts of the assembly from the rear. The assembly is particularly useful for equipping helicopters with lateral exhaust gas turbine engines, and it can be original equipment or retrofitted. The assembly serves to reduce the infra red emission from the helicopter, to defeat infra red homing missiles.

Abstract: An exhaust pipe outlet is surrounded by a jacket part having an inlet of ger diameter, permitting air to be drawn into the jacket part to isolate it from contact with the hot exhaust gases. Blocking air may be injected at the downstream end of the jacket part.

Abstract: A method of reducing the visible flash caused from afterburning of a rocket otor by injecting a fire extinguishing suppressant material into the exhaust gases from the rocket motor and injecting the fire extinguishing suppressant material near the exhaust end of the rocket motor nozzle and about an internal periphery of the exhaust nozzle. An effective fire extinguisher suppressant includes fluoro halogenated carbon compounds and specifically CBrF.sub.3.

Abstract: Thrust augmentation apparatus for a propulsive gas jet 11 including: an outer augmentor housing 15 and an inner augmentor housing 21 arranged coaxially with the jet 11. A minor air flow 25 is drawn into the inner passage 24 by an ejector effect, that flow 25 driving turbine vanes 28 projecting inwardly but terminating short of the jet 11. The vanes 28 transmit drive to fan blades 13 in the outer housing 15 to promote a thrust augmenting air flow 14. As an alternative to turbine vanes 28, gas scoops 32 may be used to develop the energy for creating the air flow 14.

Abstract: The core engine of a mixed exhaust turbofan aeroengine is provided with a conical afterbody. The normal outlet guide vanes which remove residual swirl from the turbine exhaust gases are dispensed with and replaced by ducts within an afterbody having entries which receive the hot gases in the same manner and at the same angle as the passages between the guide vanes would have done. The hot ducts, whose aspect ratio is preferably transformed between their upstream and downstream ends, extend through the afterbody in substantially straight paths to avoid aerodynamic losses, and intersect its conical surface to form preferably slot-like nozzles from which the turbine exhaust gases issue as flattened jets. The exhaust jets partake of the original axial and tangential/swirl velocity components of the turbine gases, plus a radial component (consequential upon the orientation of the ducts) to achieve good penetration of the bypass stream.

Abstract: The exhaust mixer can be classified as being of the multi-lobed type, with troughs between the lobes. The lobes and troughs comprise confronting pairs of flow surfaces which are twisted between their upstream and downstream ends such that a vortex flow system is established downstream of the mixer to encourage mixing between the bypass airstream and the turbine exhaust stream. The downstream edges of the twisted flow surfaces are in the form of sinuous curves which destabilize the vortex system and cause the vortices to burst, hence increasing the mixing efficiency.

Abstract: A gas turbine engine infra-red radiation suppressor comprising an exhaust nozzle which is surrounded by a duct having a plurality of diffuser vanes at its downstream end. The exhaust nozzle and duct constitute an ejector which is powered by the exhaust efflux from the exhaust nozzle and draws ambient air into the duct through a gap between the exhaust nozzle and the duct. The air serves to cool the exhaust efflux and thereby reduce its infra-red radiation emission, and the diffuser vanes prevent direct line of sight of the hot exhaust nozzle.

Abstract: A bypass gas turbine aeroengine has an exhaust mixer of the lobed type. The trailing edges of the confronting sides of each lobe are cut back to form notches or scallops in the sides of the lobe. To reduce aerodynamic losses and engine length and weight, the final turbine stage within the engine core is without outlet guide vanes so that the turbine exhaust gas stream issuing from the turbine has a substantial swirl component of velocity. Correction back to an axial direction of mean flow at the downstream end of the exhaust mixer nozzle is achieved by making the area of the scallop in one of the confronting sides of each lobe greater than the area of the scallop in the other side, the arrangement being such that sufficient of the turbine exhaust stream effuses from the larger scallops in directions contrary to the swirl component of velocity to produce the desired correction.

Abstract: An exhaust mixer of the multi-lobed type for a mixed stream turbofan. In order to promote cortical mixing between the turbine exhaust stream and the fan air stream, the flow surfaces defining the lobes--and the troughs between the lobes--are twisted between their upstream and downstream ends so that opposing sides of each lobe and each trough comprise flow surfaces twisted in opposing senses. Noise suppressing jet propulsion nozzles can be produced with a similar construction.

Abstract: Jet propulsion powerplant comprising a gas producer 11 having a first flow duct 12 for receiving the output of the gas producer 11. The flow duct 12 includes a nozzle 13 having a center body 16 which has an upstream part 17 and a downstream part 20. Motors 22 are provided for expanding and contracting the downstream part 20 relative to the upstream part 17. A second flow duct 33 having an inlet 30 openable to airflow and connected to the interior of said upstream part 17 is provided. An outlet 24 from the interior of the upstream part 17, is provided at the downstream end of the upstream part 17. The outlet 24 opens into the interior of the first flow duct 12 by contracting the downstream part 20 relative to the upstream part 17. By such an arrangement, infrared radiation may be suppressed when necessary by opening the inlet for air flow and controlling the upstream and downstream parts so that there can be a mixing of air with exhaust gases which reduces the mean temperature of the exhaust gases.

Abstract: An exhaust mixer for a turbofan aeroengine can be classified as being of the multi-lobed type, with troughs between the lobes. Good mixing efficiency together with good aerodynamics, short axial length and low weight is achieved by forming the mixer from flow surfaces which are longitudinally twisted between their upstream and downstream ends, opposing sides of each lobe and trough being of opposite twist. Between the upstream and downstream ends of the twisted flow surfaces, their latitudinal contours become approximately S-shaped so as to define outer portions of the lobes, inner portions of the troughs and the opposed sides of the lobes and troughs.

Abstract: Film cooling apparatus adapted to be connected into a conduit carrying a hot exhaust gas. The apparatus comprises single walled contoured duct means connectible to said conduit and a center-body aerodynamically shaped and supported within said duct means so as to form therewith an annular channel of zero pressure gradient. Slot means are provided in the single walled contoured duct means and in the center-body to enable a flow of cooling air over exterior surfaces thereof to maintain said surfaces at an acceptably low temperature. A network of ducting carries the cooling air to the contoured duct means and interior of the center-body. The duct means and center-body are preferably of circular cross-section taken orthogonally of the overall flow direction. The center-body is an axisymmetric bulb having annular slots for directing the cooling air over the exterior of said bulb.

Abstract: A device for shielding a heated surface from infra-red detection through an opening adjacent to the heated surface. The device includes a gas-conducting member, which is adapted to receive heated gases, and has an exterior surface, an interior surface, an inlet for receipt of heated gases from the opening, and an outlet for the discharge of gases. The gas-conducting member has a configuration which blocks the inlet to the member from line-of-sight view through the outlet to the member. Additionally, the device draws cooling air over the exterior surface of the gas-conducting member. The cooling air may then be mixed with the heated gases within the gas conducting member. This provides cooling of the gas-conducting member to prevent the member from being visible to infra-red detection and may also provide cooling of the gases which are discharged from the outlet of the gas-conducting member by mixing of the heated gases with the cooling air.

Abstract: A fairing added to the upstream end of the lobe of conventional lobed mixers or inverters for a gas turbine engine redirects the boundary layer so as to improve engine performance.

Abstract: An infrared suppressor system for gas turbine engine is provided for suppressing infrared radiation associated with the hot metal parts of the engine and with the hot exhaust gases exhausted from the engine.

Abstract: In a by-pass gas turbine engine, the by-pass exhaust flow is mixed with the core engine exhaust flow internally of the engine before passage through the final exhaust (propulsion) nozzle. The exhaust flow mixer comprises alternate inwardly and outwardly inclined substantially planar "fingers", which are arrayed around and attached to the circumference of the aft end of the core engine and extend generally downstream thereof. The fingers are effective to deflect the exhaust flows by virtue of the Coanda effect.

Abstract: A turbofan engine has an exhaust arrangement for the bypassed air and turbine exhaust gases providing for mixing of the two before a common propulsion nozzle. The turbine exhaust gas is directed to a number of circumferentially spaced exhausts, the outlets of which are inclined to the axis of the engine. A baffle extending from the end of the bypass duct into the common exhaust duct divides the bypass air into a portion inside and a portion outside of the baffle, the former mixing initially with the turbine exhaust gases and the resulting mixture then being mixed with the remainder of the bypass air. The baffle includes lobes which extend downstream and inwardly so as to obscure the outlets of the turbine exhaust from the jet nozzle, thus minimizing thermal radiation through the nozzle.

Abstract: A single point attachment for a unitary tail pipe plug and convoluted lobe mixer supports the assembly in the tail pipe of a turbofan engine.

Abstract: An apparatus for and method of suppressing infrared radiation emitted from hot metal parts at the aft end of a gas turbine engine and from the exhaust gas plume thereof are provided and such apparatus comprises a dual purpose ejector vane assembly operatively associated with the engine for introducing cooling ambient air into the hot engine exhaust gases and hiding the hot metal parts wherein the assembly comprises a tubular duct structure comprised of two cooperating portions defined by an upstream portion and a downstream portion with the upstream portion having a discharge end of a particular area and the downstream portion having an inlet end provided with an inlet area which is larger than the particular area to define an annular space therebetween for receiving cooling ambient air therethrough by ejector action during operation of the engine, and one of the portions has at least one vane providing at least one stream of cooling ambient air by ejector action completely across the duct structure which ser

Abstract: An air-cooled contoured plug fitted within the engine tailpipe to physica block any direct view to the turbine section. A vortex cavity is provided around the plug just aft of the plug maximum diameter in order to reduce the length of the cone-shaped plug. The trapped vortex reenergizes the boundary layer built up along the cone surface and allows the flow of hot gases to turn the corner without separating.

Abstract: A variable area exit nozzle arrangement for an aircraft engine having a substantially reduced length and weight which comprises a plurality of longitudinally movable radial vanes and a plurality of fixed radial vanes, the movable radial vanes being alternately disposed with respect to the fixed radial vanes, and means for displacing the movable radial vanes along the longitudinal axis of the engine relative to said fixed radial vanes, said radial vanes radially extending across the main exhaust flow of the engine.

Abstract: An ejector-type engine thrust augmentor intended for use in aircraft, e.g. in agricultural aviation. The thrust augmentor comprises an ejector shroud and a shell in the form of a truncated cone. The shell is located between the nozzle and the ejector shroud. The large-diameter inlet section of the shell faces the outlet section of the nozzle whereas the small-diameter outlet section of said shell faces the inlet section of the ejector shroud. The shell has longitudinal slots spaced at equal distances from one another. Due to the efflux of air from the longitudinal slots the stream flowing out of the nozzle acquires a complex cross section with a large surface area. This increases considerably the thrust increment with substantially smaller size and weight of the thrust augmentor.

Abstract: An infrared radiation suppressor secured to the discharge end of a gas turbine engine has a series of movable vanes maintained in an open trailing edge configuration in which they form converging flow passages for the gases emanating from the gas turbine engine and passing between the vanes, thereby decreasing the gas static pressure at the vane trailing edges below ambient levels. Flow passages in heat exchange relationship with the duct walls of the suppressor carry ambient air through the passages to a point downstream of the vanes. The lowered static pressure at this point causes ambient air to flow through the passages and into the gas stream, thereby cooling the duct walls and the gas stream. The hollow center of the movable vanes are also open to ambient air at the outer ends. The lowered static pressure at the vane trailing edges also causes large quantities of ambient air to enter into the hollow vanes and out the trailing edges into the gas stream further cooling the gases.

Abstract: To suppress jet noise emanating from a ducted-fan turbojet engine, an improved exhaust mixer assembly is disclosed that is mounted between the engine and the exhaust nozzle and that mixes the flow of high-velocity primary gases (turbine exhaust) with the lower-velocity air from the fan duct in a manner that achieves a significant reduction in the proportion of noise-causing high velocity gases while maintaining approximately the same thrust from the nozzle as other mixer-equipped engines. The mixer assembly includes an annular sleeve, a bulb-shaped plug disposed concentrically within the sleeve, and an annular corregugated mixer duct coaxially positioned between the plug and sleeve wherein these components are arranged so as to receive the primary and fan flows and separately redirect these flows within the assembly so that the flow of primary gases is rearwardly divergent while the flow of fan air is rearwardly convergent.

Abstract: An apparatus for and method of suppressing infrared radiation emitted from hot metal parts at the aft end of a gas turbine engine and from the exhaust gas plume thereof during engine operation is provided and comprises a multiple purpose ejector vane assembly operatively attached to the engine for introducing cooling ambient air into the hot engine exhaust gases and hiding the hot metal parts and means attaching the vane assembly to the engine with the vane assembly comprising a duct structure for receiving and confining the engine exhaust gases and a plurality of radial ejector vanes supported by the duct structure for introducing cooling ambient air into hot engine exhaust gases during engine operation by ejector action while simultaneously imparting a spiral swirl to both the cooling ambient air and the exhaust gases with the swirl promoting mixing of ambient air within the duct structure and causing additional entrainment of ambient air downstream of the duct structure.

Abstract: A radiant-energy-sensing power system applicable to aircraft having jet-type engines, vehicles having gas turbine engines, and missiles, comprising photovoltaic type cells mounted in the proximity of the combustion chamber of a jet engine and the aft end of a missile whereby the photovoltaic solar cells receive a portion of the radiant energy from the burning of the jet or missile fuel and convert same to electrical energy for use in the aircraft, missile, or vehicle.

Abstract: A low noise mixer apparatus for mixing the turbine exhaust effluent of a turbofan gas turbine engine with a portion of the air flowing from the engine fan stage prior to discharge from the engine is disclosed. The mixer is of the daisy variety, having a tubular mixer section that includes a number of axially extending, circumferentially spaced lobes with the tubular mixer section coaxially mounted around the engine plug. An outer duct coaxially surrounds the plug and mixer section. The turbine exhaust flows through an annular passage formed between the exterior surface of the plug and the interior wall of the mixer section and the fan air flows through an annular passage formed between the inner surface of the outer duct and the outer surface of the mixer section.

Abstract: 1.

Abstract: A thrust augmentation technique wherein a primary gas stream is directionally switched at a high rate to produce flow discontinuities in the interest of increasing efficiency. Apparatus in accordance with the invention includes a fluidic switch, particularly a controlled expansion thrust vector control nozzle, which delivers a pulsating primary gas stream to an eductor or lift surface.

Abstract: Apparatus for suppressing infrared radiation emitted from hot metal parts at the aft end of a gas turbine engine and from the exhaust gas plume thereof is provided and such apparatus employs components which utilize an ejector principle to provide cooling action utilizing ambient air and such components may be provided with means for adjustment thereof to vary the amount of cooling ambient air.

Abstract: An infra-red radiation suppressor adapted to be positioned to alter the flow of the exhaust gases of a turbo-shaft engine and sized to block view into the engine outlet and including self-pumping ejector means to cool the visible surfaces of the suppressor.BACKGROUND OF THE INVENTION1. Field of InventionThis invention relates to infra-red radiation suppression and more particularly to an infra-red radiation suppressor which is adapted to be mounted to block the view into the outlet of a turbo-shaft engine and to intercept and alter the flow of exhaust gases thereof and which includes self-pumping ejector mechanisms to provide cooling of the exposed suppressor parts.2.

Abstract: An infrared suppression system is provided for an aircraft gas turbine engine for reducing the level of emitted infrared radiation from the engine exhaust. The hot exhaust stream emitted from the engine is mixed with the cooling airflows received from a plurality of sources in order to more effectively reduce the level of emitted infrared radiation. In addition, the infrared suppression system prohibits a direct line of sight back into the core engine.

Abstract: Successful flight of high altitude military aircraft is dependant, in part, pon the ability of the aircraft to remain undetected during flight. However, the hot gas plume is a prime source of infrared radiation, and highly sophisticated infrared sensors have been developed in recent years. A particularly effective infrared radiation suppressor is the plug-type exhaust system. This invention increases heat exchange relationships in the plug-type infrared radiation suppressor without significantly penalizing engine power during suppressor operation.

Abstract: This invention disclosure relates to the incorporation of a high nitrogenntaining compound selected from tetrazole and bitetrazole in the form of a doughnut forward of the nozzle throat or in the form of a toroidal ring attached to the aft end of the nozzle exit cone. Both have been demonstrated as an effective means of reducing the quantity of water in the exhaust plume to an acceptable level which does not impart adverse effects on sensors or cause a reactive effect on the graphite constituents of the rocket nozzle. The compound, bitetrazole or tetrazole, can also be incorporated into the solid propellant where it will function similarly as a means or mechanism for water removal from the exhaust plume. Because of its contribution to the propellant's performance through the generation of near-incompressible gases, N.sub.2, H.sub.2 and CO, it is a desirable propellant ingredient.