Abstract: Flow rate of coolant air is increased upon elevated nozzle gas temperatures to increase nozzle liner cooling effect. A hot side curved plate is superposed over a cold side curved plate which overlays a pressurized cooling air cavity. First and second sets of apertures are formed through the first and second plates respectively. At low temperature operation, the gap between the plates is small and the staggering of the apertures restricts the flow rate of cooling gas through the plates. As temperatures rise, the hot side plate thermally expands and the gap between the plates increases to reduce the mechanical impedance effect of the staggering and to thus increase coolant flow rates.

Abstract: A precooling heat exchange arrangement includes a hollow fairing mounted on a forward side of an engine mounting structure extending radially across an annular fan duct of a gas turbine engine. The fairing has an aerodynamically-shaped external wall disposed in the main air-flow through the fan duct, spaced upper and lower internal plenums and a middle internal plenum disposed therebetween and sealed therefrom. A conduit routes hot bleed air flow from the engine to and from the lower and upper plenums of the fairing and at least one heat exchanger is mounted in the fairing.

Abstract: Cooling ambient air is induced through openings in the upstream portion of each divergent flap at intermediate throat areas where the nozzle pressure is below ambient pressure. A barometric damper in these openings prevents outflow of hot gases when operating near the minimum throat area and maximum throat area since the internal pressure is above ambient pressure during such operation.

Abstract: A hinge for pivotably connecting upstream and downstream wall sections of an exhaust nozzle of a gas turbine engine. Each wall section includes a liner spaced from the interior surface of the wall section to define respective first and second cooling air flow passages therebetween. One of the wall sections includes a curved end portion and the hinge includes a leaf seal which extends from the other wall section and biases against the curved end portion to form an air tight seal and define, at least in part, a plenum at the hinged connection of the wall sections. The plenum provides an air flow communication path between the first and second cooling air flow passages to transfer cooling air from the air flow passage of the upstream wall section to the air flow passage of the downstream wall section to thereby increase the efficiency of cooling of each of the wall sections.

Abstract: An air intake suitable for an aerospace propulsor comprises a duct in which are provided two pirmary heat exchangers arranged in parallel relationship and a secondary heat exchanger downstream of the primary heat exchangers. The primary and secondary heat exchangers are arranged to place a cryogenic fluid in heat exchange relationship with the air flow through the duct. Icing of the primary heat exchangers is controlled by interrupting the flow of cryogenic fluid to each of the primary heat exchanger in turn. Thus while one heat exchanger is subject to ice accretion hereon, the temperature of the other increases sufficiently for de-icing thereof to occur.

Abstract: Disclosed is an apparatus and a method for cooling a rotatable convergent side disk in a two-dimensional nozzle for a gas turbine engine, in which coolant is supplied and exhausted through concentric conduits, the cooling requirements of a liner assembly are reduced by use of a thermal barrier coating, and exhaust gas from the nozzle is prevented from aspirating into the side disk by use of a liner which is impervious to the exhaust gas.

Abstract: Disclosed is a device for cooling the trailing edge segment of a liner on a convergent flap of a nozzle on a gas turbine engine. The trailing edge cooling device enhances the cooling of the liner without introducing turbulence into the coolant, thereby allowing the coolant to be used to film cool downstream components. In addition, the present invention increases the longitudinal rigidity of the trailing edge of the liner to provide support for the trailing edge without significantly reducing the lateral flexibility of the liner required for thermal expansion.

Abstract: A variable area, two-dimensional nozzle for exhausting a hot stream of combustion gases from a jet engine comprising upper and lower movable exhaust flaps disposed between stationary sidewalls for defining at least a portion of the exhaust path of the nozzle, each sidewall having an inner surface and outer surface. A heat exchange baffle is disposed on the outer surface of each sidewall for heating the outer surface of the sidewall to reduce the temperature differential between the inner and outer surfaces during operation of the nozzle. Ports disposed in the sidewall are provided for directing a source of hot gas into the heat exchange baffle.

Abstract: The wall of a structural component that is subject to high thermal and mechanical stress, such as a position control rocket drive, has a plurality of grooves in its surface for an improved heat discharge by radiation emission. The grooves are cut into the wall surface and have a substantially U-type cross-sectional shape with parallel sidewalls and a substantially rounded groove bottom. The heat emission efficiency is substantially improved by making the groove depth (t) to be about 100 .mu.m and the groove width (b) to be at least 20% of the groove depth, thus (t/b) is at least 5. Additionally, the maximally permissable groove shape tolerance over the entire groove length must be .+-.1 .mu.m and the smallest spacing between neighboring grooves is about 10 .mu.m.

Abstract: An exhaust nozzle for a gas turbine engine comprises a substantially tubular duct structure to which is mounted flow directing flaps for varying the throat area of the nozzle. The duct structure is progressively shaped and deformed as it extends in a downstream direction to provide straight upper and lower lips to which respective upper and lower flaps are pivotally attached for selectively vectoring the exhaust flow. The opposing sidewalls extend vertically within the duct structure and protrude therefrom between which the flaps and exhaust orifice is thereby defined within an essentially tubular duct.

Abstract: A propulsion system for reusable space-based vehicles is presented wherein the propulsive working fluid is atmospheric gas. Acceleration or deceleration propulsion is obtained by expelling or ingesting atmospheric gas respectively. Consequently, propulsive working fluid expelled during accelerating forward propulsive maneuvers is automatically replenished during decelerating retro propulsive maneuvers. The refueling retro thrust is generated by a large diameter hypervelocity has inlet diffuser mounted at the front of the vehicle which scoops up atmospheric gas while traversing through the tenuous upper regions of a planet's atmosphere. The vehicle thereby transfers a portion of its momentum to the collected gas which was initially at rest in the atmosphere. This transfer of momentum generates a decelerating retro thrust by a reverse application of the theory of classical rocket propulsion.

Abstract: A cooling arrangement for the trailing edge of a nozzle flap 18 has a trailing edge liner 30,54 and a baffle plate 32,55. Air from plenum 22 passes through openings 38,54 to cool the trailing edge liner. Expansion of the nozzle liner 18 causes abutment seal 52 to open, increasing cooling air in proportion to the temperature of the nozzle liner.

Abstract: A cooled liner assembly for a nozzle has a plurality of longitudinally aligned support hinges secured to a support plate. A thin plate liner of arcuate shape is hinged to the support hinges with cooling air supplied between the liner and support plate. The liner is lightweight resisting the differential pressure of 25 psi in membrane hoop stresses, with components experiencing bending moments remote from the hot gas inside the nozzle.

Abstract: A cooling air diverter (8) is responsive to exhaust nozzle configuration, directing cooling air (2) to a reverser vane isolation valve (9) during forward thrust operation, and to a conduit (10), which forms part of a reverser vane access passage (17), during reverse thrust operation. The cooling air diverter includes a pivotal arm assembly (18) with inner (22) and outer (23) flaps independently movable about a first common hinge (19), and a floating flap (24) pivotable about a second hinge (25) fastened at the outward end of the inner flap. Flap movement and position is determined by contact with the isolation valve, which moves in response to thrust redirection. By utilizing an existing movable nozzle member to actuate the diverter, directional control of the cooling airflow is achieved without requiring additional actuators or complex mechanical control devices, minimizing complexity and optimizing nozzle weight.

Abstract: A gas turbine exhaust nozzle capable of long term, reliable operation is disclosed. Nozzle cooling concepts specifically directed to convergent-divergent exhaust nozzles are developed. The exhaust nozzle disclosed has a cooling liner which is strategically positioned in the nozzle to take advantage of aerodynamic conditions along the axial length of the nozzle.

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: The invention comprises a system for cooling a component in a gas turbine engine, and, in particular, for cooling an engine electronic control thereof. The cooling system includes a housing for mounting the control having a plurality of heat transfer fins extending outwardly therefrom. The housing is mounted in the engine upstream of a compressor and to a front frame having an aperture through which the fins extend. The front frame defines a flowpath to the compressor and the fins extend into the flowpath without adversely affecting the aerodynamic airflow pattern thereof. In a preferred embodiment, the fins extend substantially only to an inner surface of the front frame, and the housing includes temperature and pressure sensors disposed below root sections of the fins.

Abstract: An improvement in the design of a staged-combustion-cycle rocket engine. The preburner 16 (or preburners) is operated at a higher temperature than that above which turbine blades will be damaged. A heat-exchanger unit 40 through which the output flow of the cooling jacket 18 of the engine is passed is placed inside the preburners 16, or in close proximity to its output flow, so that heat energy is transferred from the output flow of the preburners 16 to the output flow of the cooling jacket 18. This lowers the preburners output flow to a temperature which will not damage turbine blades and raises the cooling-jacket output flow temperature. Since the output flow of the cooling jacket 18 is fed to the low-pressure turbines 22, the increased temperature raises the pressure of the low-pressure turbines 22 so that their output of flow rate is increased and the flow rate to the engine is increased, thereby increasing engine output power and 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: Insulation material lines the inner wall of the case of a gas turbine engine and controlled hot and/or cold air is selectively impinged on the outer wall of the case so as to maintain a minimum gap between the outer peripheral edge of the rotating blades relative to their tip seal means for increased thrust specific fuel consumption (TSFC).

Abstract: Methods and apparatus for improving the thrust specific fuel consumption (TSFC) of a gas turbine engine employing an exterior active clearance control system are disclosed.The pressure within the nacelle compartment to which active clearance control air is discharged is operated under altitude cruise conditions at a level on the order of one to two and one-half pounds per square inch (1-21/2 psi) above the ambient atmosphere. Flow discharging from the nacelle is directed through an aft facing vent nozzle for purposes of thrust recovery.

Abstract: A single valve serves the multiple purpose of controlling cool airflow for either blade tip clearance control (active clearance control) or ventilation control of a jet engine installed in a nacelle of an aircraft. Means for blocking flow to either or both are contemplated as a fire retarding feature.

Abstract: An auxiliary air system contained within the nacelle of a gas turbine engine having the functions of cooling engine components and measuring air inlet temperature. The system comprises an air ducting pipe, temperature sensors extending into the pipe, a structure to be cooled, such as an electronics module, preferably with a heat transfer chamber, an air flow inducer, and, if desired, means for directing air onto other engine components.

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: An active clearance control (ACC) for a turbofan engine is disclosed herein where the cross section of the external spray bars are fabricated in square or substantially square configurations.

Abstract: A ramjet powered vehicle having a bleed slot in the subsonic diffuser, for the ramjet combustor, which supplies air to a turbine for supplying power to vehicle accessories. A vortex tube is provided between the bleed slot and the turbine to provide a cool air supply. Radar absorbing material is positioned adjacent ramjet inlet with a cooling duct provided to supply cooling air from the vortex tube to the ramjet inlet cowl lip to provide cooling for the radar absorbing material.

Abstract: Apparatus is disclosed for minimizing the infrared radiation emitted at the aft end of a bypass fan type turbine engine. Minimization is accomplished by ducting cool air from the secondary bypass airstream through an annulus to form a sheath of cooler air around the gas stream as it is discharged from the engine tailpipe. The sheath of air educted along the inside surface of the engine tailpipe minimizes infrared radiation in two ways. First it reduces the operating temperature of the tailpipe thus keeping radiation therefrom to a low level. Second, the cool outside air becomes entrained in the hot gas stream discharged from the turbine. This results in a reduction of the effective temperature of the gas plume and suppresses infrared radiation therefrom.

Abstract: An air-to-air heat exchanger is provided for a gas turbofan engine to significantly reduce the quantity of cooling air that is presently needed to effectively cool the hot turbine parts. Typically, the turbine is internally cooled with air bled from the compressor which, though cooler than the turbine, has been heated due to the work done on it by the compressor. In accordance with the present invention, the heat exchanger is located internally of the bypass duct to place in heat exchange relationship a captured portion of the relatively cool bypass flow and this warmer compressor bleed air, thereby cooling the turbine coolant and significantly reducing the amount of such coolant required. This results in a decrease in engine specific fuel consumption.

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 cooling control system for a convergent-divergent gas turbine exhaust nozzle which permits automatic ducting of cooling air during the augmented mode of engine operation. The convergent flaps of the nozzle have longitudinal ducts embedded therein with a pair of openings near the aft extreme of each of the convergent flaps and openings located in the forward half of the convergent flaps. The convergent seals overlap the convergent flaps and are slideably mounted for positioning over the aft openings on the flaps. A positive pressure is generated under the convergent flap liner and seal liner when the convergent seal is opened to allow cooling air to be ducted through the flap. The positive pressure forces the convergent flap and seal liners up toward the center line of the nozzle.

Abstract: A structurally compact air-to-air heat exchanger, for a gas turbine engine of the fan bypass type, that permits a lower percentage of cooling air, than is presently needed in the art, to cool effectively the hot turbine, and its parts, of the engine. This goal is achieved, in part, by using a portion of the cool flow of fan air as a heat sink, without disturbing the flow of the fan air stream. The heat exchanger is disposed internal of the engine, and, it includes a plurality of flow tubes through which flows the hot cooling air, with the flow tubes positioned in a crossflow relationship with and to a portion of the cool flow of fan air. Three (3) variations of the preferred embodiment of the heat exchanger also are taught.

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: A filter-cooler is provided for use with a rocket motor to cool and filter ighly aluminized hot gases from around 5800.degree. F. to around 2000.degree. F. The cooled and filtered gases are then usable, for example, in thrust vector control or other mechanisms associated with the rocket. In the present system the cooler section is placed ahead of the filter section so that alumina present in the gases begins to solidify ahead of the filter and thus may be more efficiently removed. The filter section comprises a plurality of graphite vortex producing geometries. The vortex direction of the baffles is reversed in succeeding baffles so that the net effect of the high rotational velocities of each vortex is used to separate the particulate contaminates from the gas stream by momentum.

Abstract: This invention relates to sealing means for a movable centerbody having collapsible panels located in the two-dimensional exhaust nozzle of a jet engine so that movement of the centerbody and collapsing its walls serves to provide thrust vectoring, variable geometry and internal nozzle expansion. Cooling air supplied internally of said centerbody is utilized to pressurize the seal to assure that the jet exhaust does not ingress into the centerbody cavity or cooling air does not indiscriminately egress therefrom.

Abstract: This invention relates to a cooling air management system for a movable centerbody having articulating panels located in the two-dimensional exhaust nozzle of a jet engine so that movement of the centerbody and articulating its panels can provide thrust vectoring, variable geometry internal nozzle expansion or other flight control functions. Cooling air supplied from a fan discharge and/or ram air is fed internally of the centerbody to enhance its operation in a hostile environment while assuring sufficient pressure to effectuate cooling throughout the flight envelope of the aircraft, which during different regimes requires different cooling loads.

Abstract: This invention relates to a seal adapted to prevent leakage at the interface of a movable plug with articulated panels and the side wall of a two-dimensional nozzle for a gas turbine engine. The seal prevents the high pressure cooling air internal of the plug from escaping to the lower pressure exhaust gases and comprises judiciously located dam-like members installed in the vent slots in the side wall fabricated from Finwall.RTM. material which material achieves indirect heat exchange relation and film cooling.

Abstract: A cooling control system for a convergent-divergent gas turbine exhaust nozzle which permits ducting of cooling air during the non-augmented mode of engine operation. A Curtain Liner is hinged at the forward end and able to fully collapse against the nozzle convergent section cutting off cooling flow. A door, connected to the nozzle, when opened allows cooling air to pass between the nozzle and the curtain liner causing the liner to move away from the nozzle wall and the cooling process to take place. Movement of the curtain is limited by a link at the end remote from the hinge.

Abstract: A by-pass gas turbine engine capable of producing an unmixed exhaust stream which comprises a core of hot turbine exhaust gases surrounded by an annular layer of by-pass air, is combined with a target thrust reverser. The ratio of the total pressure of the by-pass air to the total pressure of the turbine exhaust gases is arranged to be greater than unity to a significant extent, and the buckets are made from lightweight materials such as titanium, light alloys or even fiber re-inforced composite materials.

Abstract: A flameholder apparatus for use in a gas turbine engine exhaust nozzle comprises at least one V-shaped gutter for holding a flame, with fasteners to mount the gutter to a nozzle support structure, the fasteners being accessible from the downstream flow direction and protruding into the gutter. To prevent the fasteners from overheating, the protruding portion is recessed in a heat shield affixed to the gutter and a portion of the combustible nozzle gas stream is passed into the heat shield and over the fastener at a velocity at least as great as the flame propagating velocity. In one embodiment, the gutter is segmented to facilitate removal through a smaller nozzle opening. Alignment pins between adjacent gutter segments provide proper gutter segment orientation, while adjacent segments are attached together through cooperating flanges on the upstream surfaces of the segments to minimize flow blockage pressure losses.

Abstract: A reduction of the opening of the clearance between the outer air seal secured to the case of a turbo-fan engine and the tip of the turbine buckets is obtained by selectively turning on and off or modulating the cool air supply. The cool air is bled from the fan discharge duct and is directed externally of the engine case adjacent the seal. Circumferentially mounted spray bars are axially spaced to fit juxtaposed to the annular flanges extending from the engine case and carry a plurality of holes judiciously located to direct the flow of cool air to impinge on the side walls of the flanges to effectuate shrinkage of the case.

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 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: A thrust vectoring gas turbine engine exhaust nozzle is provided with a variable area flow path wherein cooling of the stationary flow path side walls is partially obtained by the film cooling technique. Regulating means, such as a valve, is provided to control the pressure drop of the cooling fluid across the walls as a function of nozzle flow path area, thus optimizing the coolant flow rate as a function of flow path area. Where a rotating bonnet-type deflector is employed to divert the exhaust stream downward to obtain a vertical take-off and landing capability, a system is provided to cool the deflector walls by both the impingement and convection cooling techniques. A favorable pressure gradient for the cooling fluid is obtained by exhausting the cooling fluid to ambient pressure whenever the deflector is deployed. Another valve is provided to regulate the flow of coolant to an expansion flap when the deflector is in its stowed position external to the flow path.

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.