Abstract: A labyrinth seal positioned between a turbine rotor and inner platforms of vanes of a turbine assembly controls the leakage flow of fluid from a chamber to the flowpath through the turbine assembly. The labyrinth seal is divided into two parts by a second chamber positioned between two adjacent fins of the labyrinth seal. The chamber is located at a predetermined position in the seal such that a predetermined pressure, sufficient to supply fluid to cool a stage of turbine rotor blades in the turbine assembly, is selected. The second chamber is interconnected to the turbine blades by passages, and a chamber. The pressure of fluid in the second chamber is less than that which would normally exist in the second chamber, because fluid is being supplied from the second chamber to the second stage of turbine rotor blades. The flow of fluid from the second chamber, through the second part of the labyrinth seal, to the flowpath through the turbine is therefore reduced.

Abstract: A diffuser for use in a gas turbine engine comprises an inner and an outer annular wall which define a divergent flow passage. The divergent flow passage is divided by a splitter to form two annular flow ducts, of different flow area. Introduction of the splitter into the diffuser to form the two annular flow ducts enables the length of the outer annular wall of the diffuser to be reduced. Reducing the length of the outer annular wall of the diffuser increases the flow area between the diffuser and combustion chamber. Air downstream of the diffuser is therefore unrestricted and moves radially outward to the ports in the head of the combustion chamber with minimum pressure loss.

Abstract: A heat exchanger comprises concentric annular arrays of parallel feeder tubes and receiver tubes which are interconnected by generally circumferentially extending heat exchanger tubes. Each heat exchanger tube interconnects one feeder tube with a corresponding receiver tube which is angularly spaced apart therefrom. In operation a first fluid flows over the heat exchanger tubes while a second fluid flows through the heat exchanger tubes. The heat exchanger tubes are so arranged that the fluid flowing through them has a component which is opposite to that of the fluid flowing over them.

Abstract: An air intake suitable for an aerospace propulsor comprises a duct which contains, in flow series, a first heat exchanger, a water separator, and a cryogen injector and a second heat exchanger. Air entering the intake is cooled by the first heat exchanger to cause the majority of the water vapor in the air to condense into water droplet form. The water droplets are then removed by the air flow by the water separator. The cryogenic injector reduces the air flow temperatures still further so that any remaining water in the air flow is converted to small dry ice crystals which do not block the second heat exchanger.

Abstract: An interturbine duct for interconnecting a gas turbine engine with a power turbine. The interturbine duct is of generally frusto-conical form and double skinned so that an annular cross-section volume is defined between the skins. Cooling air introduced in a generally tangential direction at the larger diameter extent of the duct follows a generally spiral path to the smaller diameter extent where it is exhausted into the efflux of the gas turbine engine. The spiral path of the cooling air ensures good heat transfer coefficients over both of the skins and obviates the need for baffles to direct the cooling air flow.

Abstract: A heat exchanger comprises a casing through which a first heat exchange fluid flows and within which is mounted a heat exchange matrix. The matrix comprises a stack of primary plates which are maintained in spaced apart relationship by corrugated sheets so that alternate flow paths for the first heat exchange fluid and a second heat exchange fluid are respectively defined. Alternate pairs of adjacent plates are interconnected by flexible enclosing members to define the flow paths for the second heat exchange fluid.

Abstract: A heat exchanger suitable for placing air and cold hydrogen in heat exchanger relationship with each other comprises two concentric annular arrays of header tubes, all the header tubes in the radially outer array being in flow communication with a first manifold while half of the header tubes in the radially inner array are in flow communication with a second manifold and the remainder are in flow communication with a third manifold. Heat exchange pipes interconnect the various header tubes and air flows over those pipes. Various valves and pipes are provided and are operable to ensure that the heat exchanger functions in two modes of operation; a first in which cold hydrogen flows through all the heat exchange pipes in a single direction and a second in which the cold hydrogen flows through alternate heat exchange pipes in the opposite direction.

Abstract: A gas turbine engine fuel injector comprises a main center body portion at the upstream end of which is located a steam injector. The steam injector is adapted to optionally direct steam into the air inlet of the main body portion so as to reduce the production of the oxides of nitrogen, and optionally increase engine power output.

Abstract: A brush seal operationally located between a rotatable shaft and static structure comprises a number of stages. The seal stage adjacent a region of low fluid pressure and its adjacent stage are spaced apart by an apertured ring. The apertures in the ring being so dimensioned as to vent pressurized fluid from the chamber and thereby reduce the magnitude of the pressure differential across the seal stage adjacent the region of low fluid pressure.