Abstract: An annular combustion chamber for a gas turbine engine establishes two toroidal primary combustion zones. This provides high combustion capacity in a short combustor. Airflow is introduced in a manner to establish the flow pattern of the vortices, and the fuel is introduced in a manner avoiding destruction of the vortices.

Abstract: Shrouds 22, 24 are welded to support braces 20 near fuel spray ring 12. A splash shield 30 is secured to shroud 22 toward which fuel 16 is sprayed. It extends between braces protecting the shroud 22 from fuel impingement. Cracking of the structure at the shroud-brace interface is avoided.

Abstract: The internal blade damper is an elongated member with a damping surface of discrete width in contact with the interior blade surfaces. Contact is continuous throughout a substantial length. The damper extends between 2.degree. and 30.degree. from the radial direction, producing a direction of contact having some radial component. Centrifugal force loads the damping surface.

Abstract: Increased aircraft control is achieved by combining reverse thruster operation with splay capability. Each of the four door sets has a pair of vanes controllable to various parallel positions. Maximum opening at 26.degree. from the vertical decreases in each direction from the maximum position. The vanes may be controlled to effect yaw and pitch control while maintaining a constant total effective flow area. Back pressure on the turbine is thereby unaffected.

Abstract: In a humid air gas turbine cycle the compressed air is humidified prior to introduction to the combustor. Compressed air before humidification is used to cool the first turbine stage rotor blades. Humidified air is used to cool the first turbine stage stationary vanes.

Abstract: Cooling air to the 1-2 turbine stage seal is supplied in parallel with air to the second vane surface from a plenum. A modulatable valve in the supply line to the plenum regulates air flow in response to a sensed temperature in the 1-2 seal area. A thermocouple is located in a bypass around a portion of the seal, being radially installed through a hollow vane and an opening in the seal shroud.

Abstract: Increased aircraft control is achieved by combining reverse thruster operation with splay capability. Each of the four door sets has a pair of vanes controllable to various parallel positions. Maximum opening at 26.degree. from the vertical decreases in each direction from the maximum position. The vanes may be controlled to effect yaw and pitch control while maintaining a constant total effective flow area. Back pressure on the turbine is thereby unaffected.

Abstract: A casing around a turbine and a casing around discharge nozzles have a concentrically arranged shell portion. The seal contains internal pressure while accommodating eccentric, expansion and axial travel. Arcuate seal segments have one leg sealing against a radial surface extending from the inner shell and the other leg against the outer shell. A linkage guides travel of the segments.

Abstract: Each convergent flap and seal has a cantilevered extension deflector. This deflector reduces the throat area at minimum throat area, and seals against a divergent flap or seal in the maximum throat area position.Cooling ambient air is induced through openings in the upstream portion of each divergent seal at intermediate throat areas. At minimum throat area the divergent flaps block these openings. At maximum throat area the deflectors block the cooling airflow path.

Abstract: A fluid cooled thermal skin is bolted to a sufficient back structure. In-line coolant flow paths are arranged to pass the cooling fluid through the bolt head. The in-line paths are recessed adjacent the bolt head to mate with flow openings in the head. In one embodiment the paths through the bolt head are parallel paths, requiring alignment of the bolt head. In another embodiment alignment of the bolt head is not required.

Abstract: Inner case 14 is supported from outer case 12 through combined vanes 32. Substantial torque loading is transferred leading to high stress levels at the roots of the vanes. Shrouds 22, 28 are thinned between support ring 20 and conical portion 18. Ribs 48 are located coincident with the radial extension of the vanes 32. With the cambered vanes the high stress location is remote from the vane ends, and flexibility is achieved at such location.

Abstract: A fuel metering and actuation system includes a main centrifugal pump 16 supplying fuel to the combustor 18. Gear pump 50 takes suction from the main pump discharge and supplies actuators 42, 44, 45, 46 at high pressure. Variable set point pressure relief valve 56 operates to decrease the gear pump pressure level when high pressure is not required. Selection valve 21 directs discharge from the gear pump 50 to the combustor 18 when the main pump 16 supplied insufficient pressure for the fuel nozzles. Bypass line 30 around the selector valve with check valve 82 permits main pump 16 discharge fuel to be used for the actuator if the gear pump 50 becomes inoperative.

Abstract: A gas turbine engine control system sends a demand signal to a fuel throttle valve. The demand signal is modified by a measured fuel flow signal during normal operation. Operating parameters such as pump speed and recirculation valve portion are sensed. Combining these sensed parameters with the known geometry of the system, a calculated pressure differential between a point upstream of the throttle valve and a point in the combustor is determined. This calculated pressure differential is applied to the known geometry of the system from before the throttle valve to the combustor, including sensed opening of the throttle valve. A calculated flow is thus obtained and compared to the measured flow. An excessive difference between the measured and calculated flows indicates flow meter error. In such a case the calculated flow is substituted for the measured flow in modifying the demand signal.

Abstract: Brush seals 30 are secured to segmented vane platforms 20. Inwardly extending bristles 42 seal against rotor 10. Outwardly extending bristles 46 seal against the vane platform 20, and also act as vibration dampers.

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 blade holder for holding blades on an integrally bladed rotor has two legs located outboard of the blade in its installed position. A collar on each blade has holes for bolting the collar to the holder. Visual alignment is possible and access to the blade for optical temperature scanning is provided. After bonding a blade to the rotor, rotation of the rotor to the next bonding position is possible without removal of the holder.

Abstract: A lightweight, integrally bladed rotor has airfoils (18) and a full hoop blade platform (26), a support ring (28) is inside and spaced from the platform, with radial webs (30) extending from the support ring to the platform. Each web is a radial extension (32) of an airfoil. A radially extending shear plate (36) is secured to the platform and the ring.

Abstract: A planetary gear system includes a plurality of planet gears, each having a journal bearing and a pin, end supported in a planet carrier. Each pin has a small diameter central portion axially extending for end support. A larger diameter outer portion is integral with the central portion at an inboard merged zone, and has cantilever sections extending outboard from the merged zone. Each pin is sized such that bending of the merged zone in one direction is countered by bending of the cantilever sections in the other direction to achieve a substantially linear bearing surface under load.

Abstract: Reverser doors on an aircraft are to be opened, closed and splayed to effect pitch and yaw control in combination with reverse thrust. A first actuator achieves open and close control. A second actuator achieves splay control through a linkage, with the first actuator located within the linkage.

Abstract: Ports through the wall of the exhaust duct and the wall of the surrounding cooling air duct, connect the exhaust duct and reverse thrust ducts. Door sets seal these ports. The door sets are contrarotated around the exhaust duct providing a symmetrical opening of the ports.