Abstract: Supersonic rotor blading in an axial-flow fan or compressor employs blades such that shock waves originating on a blade are canceled at the intersection of the wave and the surface of an adjacent blade by virtue of a blade configuration such that the shocks intersect the blade surface at a line of properly oriented change in flow angle of the blade surface. A three-wave system is employed.

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 jet propulsion engine and a method of operating a jet propulsion engine for propulsion of an aircraft over a wide range of speed from zero to supersonic. The engine is a turbofan type with a duct burner and with separate variable exhausts from the duct burner and from the gas turbine engine. The gas turbine core engine includes a gas generator and a low pressure turbine which drives the fan. The fan includes variable outlet guide vanes and the low pressure turbine includes a variable first-stage nozzle. The engine is operated as a normal duct burning by-pass jet engine from zero air speed up to about Mach 3. The fuel to the core engine is shut off through a transition range of speeds. Above this range the engine operates with only the duct burner supplied with fuel, with the gas generator windmilling, and with the low pressure turbine continuing to drive the fan to supercharge the duct burner, which operates as a supercharged ramjet.

Abstract: A porous laminated sheet adapted to be cooled by air flowing through the sheet from a rear face to a front face and to discharge the air through outlets in the front face at an angle to the normal to the surface. It is particularly adapted for use as a wall of a combustion liner. The sheet has a front layer with grooves leading to outlets from the front layer and has a rear layer defining channels from the exposed face of the rear layer into the grooves.

Abstract: A turbine nozzle has a row of vanes each rotatable about an axis extending spanwise of the vane. Each vane is rotated by a shaft which extends through one shroud of the stator vane stage. The free end of each vane is sealed by a flexible seal ring structure made up of overlapping flexible leaves. These leaves are fixed to the nozzle inner shroud at the downstream side of the vanes and motive fluid under pressure is admitted upstream of the vanes to the space between the leaves and the shroud so that the pressure difference across the leaves biases them into engagement with the ends of the vanes. The purpose is to seal against leakage past the vane ends without causing undue frictional resistance to varying the vane setting angle.

Abstract: A gas turbine power plant, particularly adapted for powering motor vehicles. The engine includes a gas generator made up of a compressor, combustion apparatus, and a turbine driving the compressor. It also includes a power turbine energized by the flow from the gas generator rotatable independently of the gas generator. The power turbine is connected through a suitable transmission to the driving wheels of the vehicle and also drives accessory loads such as the engine fuel and oil pumps, an alternator, air conditioning, a power steering pump, and the like in the vehicle. The gas generator is substantially free of any accessory drive load, which improves the acceleration characteristics of the engine.The engine fuel control includes an underspeed governor which responds to power turbine speed and increases fuel flow as required to maintain power turbine speed at a minimum value high enough to power the accessory devices satisfactorily.

Abstract: A gas turbine power plant, particularly adapted for powering motor vehicles. The engine includes a gas generator made up of a compressor, combustion apparatus, and a turbine driving the compressor. It also includes a power turbine energized by the flow from the gas generator rotatable independently of the gas generator. The power turbine is connected through a suitable transmission to the driving wheels of the vehicle and also drives accessory loads such as the engine fuel and oil pumps, an alternator, air conditioning, a power steering pump, and the like in the vehicle. The gas generator is substantially free of any accessory drive load, which improves the acceleration characteristics of the engine.The engine fuel control includes an underspeed governor which responds to power turbine speed and increases fuel flow as required to maintain power turbine speed at a minimum value high enough to power the accessory devices satisfactorily.

Abstract: A diffuser for a centrifugal compressor has an annular array of vanes which are movable to vary the configuration of the diffusing passages between the vanes. Each vane includes a first leaf pivoted adjacent the leading edge of the vane and a second leaf pivoted on the first leaf. These leaves have slots extending chordwise of the vanes which are engaged by pins extending from an actuating ring rotatable about the axis of the diffuser. The slots in the two leaves are at an angle to each other so that when the ring is rotated and the pins move chordwise of the vanes in the leaves, the angle of the first leaf to the radial direction is changed and also the second leaf is moved relative to the first leaf to vary the width of the passage in addition to such variation as results from the change in the angle of the first leaf.

Abstract: A combustion liner for a gas turbine combustion apparatus is composed of a series of ceramic wall rings coaxially aligned from the upstream to the downstream end of the liner. The ceramic rings are connected so as to be free to expand radially relative to each other while maintaining alignment. One type of connection between the rings involves notches distributed around the ends of a ring and bosses distributed around the adjacent end of the next ring entering into the notches. Another type of interconnection involves notches distributed around adjacent ends of two ceramic rings with a metal ring disposed between them having bosses which engage in some of the notches to align the parts. The liner is supported by supports at the ends of the liner from an outer casing. One support includes a spring to accommodate relative expansion of the liner and outer casing.

Abstract: The exhaust duct of a turbojet engine, which is annular with an enlarged plug or bullet at the exhaust end, includes an arrangement of the outer wall to block direct sight of the turbine of the engine through the exhaust duct. There are two rows of inwardly directed streamlined lobes on the outer wall of the exhaust duct with the lobes of one row staggered with respect to those of the other so that the two sets cooperate to block direct view of the turbine through the gap between the plug and the outer wall of the exhaust duct.

Abstract: A circuit for generating a potential indicative of torque. The circuit responds to the phase angle between the AC signals generated by two generating coils or magnetoelectric pickups, each excited by a toothed wheel. The two toothed wheels are connected to different points along a shaft transmitting power between an engine and its load. The windup or torsion of the shaft is proportional to torque; therefore, the relative phase angle of the signals from the two pickups is also proportional to torque. Each generating coil is connected to a high-gain input amplifier which generates a square-wave signal in phase with the signal from the coil. Each input amplifier triggers a pulse generator which generates a pulse the leading edge of which is in fixed phase relation to the pickup signal. The two pulse generator outputs are connected to a flip-flop circuit to generate a zero output signal during the interval between the two inputs to the flip-flop. The duty cycle of this signal is indicative of torque.

Abstract: A radial-flow turbomachine (centrifugal compressor or centripetal turbine) is provided with a lip extending along the free edge of each rotor blade from the inlet to the outlet end of the blade. The lip extends from the pressure face of the blade and serves to minimize leakage between the edge of the blade and the adjacent fixed shroud past which it is rotated.

Abstract: A compressor or turbine rotor stage includes a wheel with a circumferential slot for retention of the roots of blades mounted on the wheel. Each side of the rim of the wheel is approximately symmetrical about a line parallel to the axis of rotation of the wheel through the centroid of the section of the rim side and is of such asymmetrical configuration about a line normal to the axis of rotation that the shear center of each side of the rim is inboard of the centroid and preferably close to or inboard of the plane of action of the radial component of the forces exerted by the blade roots on the sides of the rim due to the centrifugal force pull of the blades.

Abstract: A combustion liner for a gas turbine combustion apparatus has a wall of ceramic material. To minimize destructive thermal gradients in the ceramic material due to local cooling by air entering the liner through ports for combustion or dilution air, the walls of these ports are isolated from the entering air by a lining for the port, either a coating applied to the wall of the port or a metal or ceramic sleeve extending through the port.

Abstract: A single-shaft gas turbine engine suited for road vehicle propulsion has variable inlet and outlet guide vanes in the compressor of the engine and a variable turbine nozzle. These variable features are called engine variable goemetry (EVG). In normal operation, the areas of the flow paths at the inlet and outlet of the compressor and of the turbine nozzle are varied with desired power level to suit varying air flow through the engine. An actuator increases the areas in response to a request for increased power output.In a braking mode, the compressor variable geometry is decoupled from the actuator and remains at a minimum flow condition while the turbine nozzle is opened as the power request decreases below a particular low value. The opening of the turbine nozzle decreases the engine power output, thus increasing its capacity to absorb power from the vehicle. Logic circuits control the coupling and decoupling of the compressor variable geometry.

Abstract: A combustion liner for a gas turbine combustion apparatus or the like has a head wall and a side wall extending downstream to an outlet for combustion products. A reaction zone is contained within the upstream end of the side wall and a dilution zone downstream. A barrier ring extends inwardly from the side wall to provide a constricted path between the zones. Combustion air is admitted from a cluster of nozzles in the head wall and a ring of nozzles extending forwardly from the side wall. Each nozzle in the head wall is axially aligned with one of the nozzles in the side wall so that air jets entering into the combustion zone through each such pair of nozzles impinge to create a high degree of turbulence. Fuel is jetted against a spatter plate in each nozzle in the head wall so that the fuel is atomized and entrained by the air flowing through the head wall air nozzle.

Abstract: A fuel and burner variable geometry (BVG) control for a gas turbine engine. Fuel is controlled in response to the product of desired overall fuel-air ratio and a value of air flow derived from gas generator turbine speed. The desired fuel-air ratio is controlled by a speed governor, and by acceleration and deceleration limits varied as a function of measured burner inlet temperature. A compensated turbine inlet temperature (TIT) signal is derived from measurement of actual turbine inlet temperature and acceleration or deceleration compensation based upon rate of change of the desired fuel-air ratio. The difference between the compensated TIT and the burner inlet temperature (BIT) is the burner temperature rise.The setting of air flow control devices in the combustion apparatus (BVG) determines the ratio of primary to total air. The desired ratio to control BVG is computed by dividing burner temperature rise by flame temperature rise.

Abstract: A combustion system with provisions to minimize undesired exhaust products including carbon monoxide, incompletely burned fuel, and oxides of nitrogen. Air entering the combustion zone of the combustion apparatus is mixed with a relatively large amount of recirculated combustion products, preferably about twice the weight of the fresh air entering the combustion zone. The combustion products which are recirculated are cooled by heat exchange with air flowing to a dilution zone of the combustion apparatus where the combustion products and air are mixed to provide the high temperature gas output of the system which is the motive fluid of a gas turbine.The recirculated combustion products are cooled to reduce temperature in the combustion zone and thereby nitrogen oxide formation and the heat extracted from the recirculated combustion products is transferred to the dilution air. The combustion products delivered from the combustion zone to the dilution zone may be diverted ahead of or after the heat exchange.

Abstract: A control system for a helicopter power plant with three power units driving the lifting rotor system through a main gearbox. Each power unit comprises a gas turbine engine of the gas-coupled type, a hydromechanical fuel control receiving electrical inputs to set a gas generator governor in the fuel control, an engine electronic control, and various engine accessories.

Abstract: A porous seal element usable as a blade tip seal in a turbomachine or as an element of a labyrinth seal is made up of a large number of strips disposed edgewise to the sealing face of the element and extending in the direction of relative movement of the seal elements. The strips have grooves extending across the strip for discharge of a cooling fluid such as air. The presence of the grooves provides a low density structure at the seal face of the seal element which may be abraded if there is rubbing contact and provides for metering of coolant at the rear face of the seal element. The seal element is fabricated by etching sheets so each sheet defines a number of parallel strips joined by weak ties and with the grooves extending across the strips; stacking the sheets and bonding them together; and then separating the bonded structure at the weak ties so that each stack of strips defines a seal element.