Abstract: An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle including a backsheet formed by a planar matrix of adjacent individually controllable elements, where each of the controllable elements has a transducer and a honeycomb cell enclosing the transducer. A facesheet is also bonded to the controllable elements. A plurality of sensors are positioned within the acoustic treatment panel for sensing acoustic pressure of the noise propagated against the facesheet. A driver is provided for electrically driving each of the transducers to effect displacement thereof in a direction substantially perpendicular to the facesheet. Circuitry is also operatively connected to the pressure sensors and the driver for controlling velocity magnitude and phase of the transducers during displacement, wherein a resulting acoustic impedance at the facesheet achieves a desired acoustic impedance boundary condition at the nacelle.

Abstract: An improved variable cycle turbofan-ramjet engine is disclosed. The engine includes a split fan assembly, a bypass channel surrounding a core engine and a mode selector valve for selectively bypassing air around an aft fan and the core engine. In a first, single bypass mode of operation, the mode selector valve allows air to flow through both a forward fan and the aft fan, and a portion of which bypasses the core engine. In a second, double bypass mode of operation, the mode selector valve allows air from the forward fan to bypass the aft fan and a portion of the air from the forward fan to bypass the core engine. In a third, ramjet mode of operation, the mode selector vane bypasses air around the aft fan and the core engine and the core engine is shut down for ramjet operation. In the preferred embodiment, the forward fan is allowed to windmill and powers a fuel pump connected thereto for providing fuel to a ram burner of the engine for ramjet operation.

Abstract: A short take off and vertical landing (STOVL) nozzle for a jet aircraft provides thrust reversing and thrust vectoring functions using two pairs of flaps. Each flap is independently actuated and controlled to allow for numerous exhaust gas exit configurations. A two dimensional or rectangular center plug extends across the nozzle throat region to allow one pair of flaps to selectively engage the plug for STOVL operation.

Abstract: A turbine airfoil has a mesh cooling hole arrangement which includes first and second pluralities of cooling holes formed within the interior structure of the side walls of the airfoil so as to extend between and along but not intersect spaced internal and external surfaces of the side walls extending between leading and trailing edge portions of the airfoil. The cooling holes of each plurality extend generally parallel to one another. The cooling holes of the first and second pluralities intersect so as to define a plurality of spaced apart internal solid nodes in the side walls having pairs of opposite sides interconnected by pairs of opposite corners. The spaced nodes define a multiplicity of hole portions of the cooling holes extending between and along opposite sides of adjacent nodes and a plurality of flow intersections interconnecting the hole portions of the cooling holes and being disposed between the corners of adjacent nodes.

Abstract: A design system for designing brackets for gas turbine engines is described. The system may be implemented with a computer workstation and includes a part model library and a drawing note library. The computer workstation is configured to receive a bracket model in electronic form as input and has a number of executable modules stored therein. The system outputs a bracket master model and detail drawings. In one embodiment, the modules include a bracket intelligence builder module for generating intelligence data for the bracket model, a bracket unfolding module for unfolding a bracket model to a flat pattern, a bracket folding module to fold a bracket flat pattern, and a bracket minimum material check module to check for minimum distances between bracket pattern features. Other modules also are described and may form a elements of the system.

Abstract: A turbine nozzle for a gas turbine engine subassembly having an axial turbine. The turbine nozzle airfoil-shaped vanes are fixedly attached to one or both of the annular inner and outer casings. Apparatus is provided to vary the vane airflow passage area between the casings and between the pressure side of one vane and the suction side of an adjacent vane. The apparatus varies the area near at least the pressure side of the one vane. Various embodiments of the apparatus include: a small pivotable flap pivotally attached to the outer casing and positioned near the pressure side of the one vane; a small movable flap attached to the outer casing to be movable along the pressure side of the one vane, and a plug member insertable into and withdrawable from the vane airflow passage through the outer casing near at least the pressure side of the one vane.

Abstract: A combustor, for a gas turbine engine, employing regenerative combustor cooling. The combustion gas flow direction extends generally longitudinally aft of the combustor fuel nozzle. A coolant flowpath between the combustor casing and the combustor liner has: 1) a longitudinally aft inlet in fluid communication with a source of compressor-derived cooling air, of lower temperature and higher pressure than diffused air from the combustor diffuser; and 2) a longitudinally forward outlet in fluid communication with the combustor fuel nozzle for "spent" cooling air to be used for combustion.

Abstract: An airfoil blade, such as a jet engine turbine rotor blade. An internal serpentine coolant circuit has a last downstream passageway bounded by four monolithic inner walls which are monolithic with at least a portion of the outer walls. Two of the inner walls are spaced from the outer walls and contain air impingement orifices creating two impingement chambers. Some coolant in the serpentine circuit exits the airfoil blade through a coolant exit in the blade tip. The remaining coolant in the circuit passes through the impingement orifices and exits the blade through film cooling holes in the outer walls.

Abstract: A wall adapted for use in a gas turbine engine between a first and a hotter second fluid includes a first side over which is flowable the first fluid, and an opposite second side over which is flowable the second fluid. An elongate slot extends inwardly from the second side and is disposed in flow communication with a plurality of longitudinally spaced apart holes extending inwardly from the first side. The holes are disposed at a compound angle relative to the second side for discharging the first fluid obliquely into the slot and at a shallow discharge angle from the slot along the second side. The holes are also disposed in converging pairs to impinge together in the slot the first fluid channeled therethrough. In a preferred embodiment, the slot has an aft surface including a plurality of longitudinally spaced apart grooves extending from the holes to the wall second side.

Abstract: A turbine blade squealer tip has a cooling passage arrangement which includes a peripheral end wall surrounding a central portion of an end cap of the squealer tip, an outer peripheral groove defined in an outer surface of the peripheral end wall being spaced outwardly from the central portion of the end cap, and a multiplicity of holes extending through the end wall from the outer groove to an internal source of cooling air flow within the turbine blade, bypassing the central portion of the end cap of the squealer tip. The outer groove which receives the flow of cooling air from outlets of the holes tends to trap the air therein so as to form an annular air seal about the outer surface of the squealer tip end wall which impedes leakage of hot gas flow past the squealer tip.

Abstract: A thrust reverser is provided for both modulating and reversing bypass flow discharged from a fan through a bypass duct of a turbofan gas turbine engine. The reverser includes an aft cowl joined to a forward cowl and having an aft end surrounding a core engine to define a discharge fan nozzle of minimum flow throat area. The aft cowl is axially translatable relative to the forward cowl from a first position fully retracted against the forward cowl, to a second position partially extended from the forward cowl, and to a third position fully extended from the forward cowl. A plurality of cascade turning vanes are disposed between the forward and aft cowls, and a plurality of thrust reversing deflector doors are pivotally mounted to the aft cowl and bound the bypass duct. The deflector doors are selectively deployed from a stowed position corresponding with the first and second positions of the aft cowl for allowing unrestricted flow of the bypass flow through the fan nozzle.

Abstract: A jet engine component, such as an aircraft gas turbine engine rotor blade or a scramjet engine fuel injector. The component has a wall portion including a first surface exposable to a cooler, higher static pressure fluid and a second surface exposable to a hotter, lower static pressure gas flow flowing across the second surface. The component further includes a generally straight film coolant passageway having an inlet on the first surface and an outlet on the second surface. The second surface has a seamless groove which is open substantially entirely along its longitudinal dimension extending from the outlet along the lower static pressure gas flow for improved film cooling of the second surface.

Abstract: A wall adapted for use in a gas turbine engine between a first and a hotter second fluid includes a first side over which is flowable the first fluid, and an opposite second side over which is flowable the second fluid. An elongate slot extends inwardly from the second side and is disposed in flow communication with a plurality of longitudinally spaced apart holes extending inwardly from the first side. The holes are disposed at a compound angle relative to the second side for discharging the first fluid obliquely into the slot and at a shallow discharge angle from the slot along the second side. In a preferred embodiment, the slot has an aft surface including a plurality of longitudinally spaced apart grooves extending from the holes to the wall second side.

Abstract: A dome assembly for a single annular combustor of a gas turbine engine is disclosed as having a first dome wall in flow communication with compressed air supplied to the combustor, the first dome wall including a central opening therein and at least one cooling passage therethrough. A baffle is spaced downstream of and connected to the first dome wall at radially outward and inward ends, the baffle also including a central opening therein. A second dome wall defining the central opening in the first dome wall is provided which extends upstream of the first dome wall. A venturi is located within the central opening of the first dome wall, with the venturi including a flange extending radially outward from the central opening, wherein the second dome wall is connected to the flange at an upstream end.

Abstract: A combustor for a gas turbine engine is disclosed which is able to operate efficiently at inlet air flows having a high subsonic Mach Number. The combustor has an outer liner and an inner liner spaced therefrom, wherein a combustion chamber is defined therebetween. A dome inlet module is provided which is in flow communication with compressed air flow from a compressor upstream thereof. The dome inlet module has an outer member fixed to the outer liner and an inner member fixed to the inner liner, wherein a flow passage is defined by the outer and inner members for the compressed air flow to flow freely from a compressor to the combustion chamber. Fuel atomizers are then utilized to inject fuel into the flow passage so that the fuel is mixed with the compressed air stream to form a fuel/air mixture which enters the combustion chamber.

Abstract: A turbine airfoil includes a plurality of internal ribs defining at least two independent serpentine cooling circuits arranged in part in different longitudinal tiers, with an outer tier circuit being disposed in part longitudinally above an inner tier circuit for differentially longitudinally cooling the airfoil.

Abstract: A shroud includes a panel having leading and trailing edges and inner and outer surfaces extending therebetween. A cooling passage extends through the panel from adjacent the leading edge to an intermediate location and is generally parallel to the inner and outer surfaces. The cooling passage has an inlet for receiving cooling air from adjacent the panel outer surface, a plurality of spaced apart turbulators disposed adjacent to the panel inner surface, and an outlet disposed at the leading edge for discharging the cooling air from the passage.

Abstract: An expansion joint includes a pair of tubular fittings joined together by a bellows for accommodating differential movement therebetween. The fittings include balls at respective distal ends thereof which engage complementary sockets fixedly joined to opposite ends of the bellows. The respective ball and sockets additionally accommodate pivotal and rotary movement. The bellows allows pressure and spring forces to engage the sockets against their respective balls for continuously seating the balls in the sockets during operation and maintaining effective seals against leakage.

Abstract: An apparatus for modulating a flow of cooling air from a compressor to a turbine in a gas turbine engine is disclosed. The apparatus includes a support member which forms a channel for receiving the cooling flow and has a throat at a downstream end with a radial orientation. A radial flow inducer is connected to the support member adjacent to the channel downstream end for accelerating the cooling flow through the throat of the support member. Apparatus for modulating the quantity of the cooling air flowing through the throat and into the turbine is provided in the form of an axially translating endwall, wherein variation of the throat area is accomplished through modulation of the endwall with respect to the support member. The support member may also house either a stationary, unmodulated axial flow inducer or a second modulated radial flow inducer in addition to the modulated radial flow inducer.

Abstract: There is provided by the present invention a brush seal including apparatus for reducing bristle vibrations, such as a damper, that engages the upstream side of the bristle pack of the brush seal so as to absorb vibrations and therefore reduce chamfering of the bristle pack.