Abstract: A rotor and a stator assembly, wherein the rotor (30) comprises at least one stage of rotor blades (32) and the stator (34) comprises at least one stage of turbine stator vanes (36). The rotor blades (32) have aerofoils and platforms (42) and the turbine stator vanes (36) having aerofoils and platforms (48). A seal (43,45) is defined between the rotor blade (32) platforms (42) and the stator vane (36) platforms (48) wherein a portion (42B) of the rotor blade platforms (42) and/or a portion (48B) of the stator vane (36) platforms (48) comprise a shape memory alloy member or a bimetallic member. The shape memory alloy member, or bimetallic member, controls the flow of cooling air through the seals (43,45) allowing a greater cooling flow at higher temperatures than at lower temperatures.

Abstract: A seal (40) provides sealing between two pressure zones (60, 62) and a rotating and non-rotating member (42, 52) by providing a first sealing member (46) between two seal lands (48, 50). A second seal (64) is mounted between the non-rotating member (52, 58) and one of the seal lands (50, 66) so as to control pressure around the seal lands (48, 50).

Abstract: A drive apparatus (10) for propelling a vehicle across a body of water is described. The apparatus (10) comprises a prime mover, for example a gas turbine engine (12), and a propelling arrangement (26) driven by the prime mover for propelling the vehicle across the body of water and thereby provide a reaction force on the prime mover. The apparatus (10) also includes a braking arrangement (42) to apply a braking force to the propelling arrangement (26).

Abstract: A gas turbine engine exhaust nozzle arrangement for the flow of exhaust gases therethrough between an upstream end and a downstream end thereof comprising a nozzle and a plurality of tabs which extend in a generally axial direction from a downstream portion of the nozzle wherein the nozzle further comprises an actuation mechanism capable of moving the tabs between a first deployed position, where the tabs interact with a gas stream to reduce exhaust noise thereof, and a second non-deployed position, where the tabs are substantially aerodynamically unobtrusive.

Abstract: A power generator comprising: a lifting body for suspension in a moving fluid; a control station; and at least two tethers for tethering the lifting body to the control station. The control station is arranged to transform oscillating tension in the tethers produced by an oscillating movement of the lifting body into mechanical motion.

Abstract: A method of detecting the change in the structure of a turbine rotor uses the steps of injecting an ultrasonic signal into the turbine rotor at a first position using a first ultrasonic transducer to produce a diffuse field ultrasonic signal in the rotor; detecting the signal in the rotor at a second position using a second ultrasonic transducer measuring the time for the signal to travel from the first ultrasonic transducer to the second ultrasonic transducer and comparing the measured time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer to the second ultrasonic transducer with a stored time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer to the second ultrasonic transducer to determine if there is a change in the structure of the turbine rotor.

Abstract: An engine nozzle is described in which the nozzle is deformable from a first state, typically a round shape, to a second state which may approach a polygon or have a fluted edge. The first and the second state defining different nozzle cross-sections whereby the nozzle can be adjusted between the first and second state for a nozzle cross-section optimised for engine efficiency. Deformation in the nozzle may be achieved through use of shape memory materials, pressure chambers, piezo-electric element deformation or other technique.

Abstract: A gas turbine engine exhaust nozzle arrangement for the flow of exhaust gases therethrough between an upstream end and a downstream end thereof comprising a nozzle and a plurality of tabs which extend in a generally axial direction from a downstream portion of the nozzle wherein the nozzle further comprises an actuation mechanism capable of moving the tabs between a first deployed position, where the tabs interact with a gas stream to reduce exhaust noise thereof, and a second non-deployed position, where the tabs are substantially aerodynamically unobtrusive.

Abstract: A method and a system (10) for exhausting gas via a nozzle (19, 21) of a gas turbine engine, for example. The system (10) comprises a nozzle (19, 21) comprising a nozzle body portion (32, 33, 74) defining a nozzle exit (42, 43), characterised in that the nozzle body portion (32, 33, 74) comprises fluid injection means (60), positioned upstream of the exit (42, 43) relative to a fluid flow (F1, F2) created by the operation of the system, for injecting fluid (68) upstream of the exit (42, 43).

Abstract: A power generator comprising: a lifting body for suspension in a moving fluid; a control station; and at least two tethers for tethering the lifting body to the control station. The control station is arranged to transform oscillating tension in the tethers produced by an oscillating movement of the lifting body into mechanical motion.

Abstract: A method of prestressing a component (30) includes the use of an electrical discharge or current to produce a plasma (39) within a medium (32) located adjacent the component (30). The plasma generates a shock wave which impacts a surface of the component to produce a region of compressive residual stress within the component.

Abstract: A method of detecting the change in the structure of a turbine rotor (24) comprises injecting an ultrasonic signal into the turbine rotor (24) at a first position using a first ultrasonic transducer (102) to produce a diffuse field ultrasonic signal in the turbine rotor (24). Detecting the diffuse field ultrasonic signal in the turbine rotor (24) at a second position using a second ultrasonic transducer (106). Measuring the time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer (102) to the second ultrasonic transducer (106). Comparing the measured time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer (102) to the second ultrasonic transducer (106) with a stored time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer (102) to the second ultrasonic transducer (106) to determine if there is a change in the structure of the turbine rotor (24).

Abstract: A control arrangement (34) for controlling the size of a gap (30) between first and second components. The control arrangement comprises first magnet means (38) to be provided on the first component, and second magnet means to be provided on the second component. The first and second magnet means are in magnetic interaction with each other across the gap (30) and the arrangement further includes control means (36) to control the size of the gap (30) the first magnet means (38) is a moveable in a first direction to cause the control means (36) to effect relative movement of the first and second components to increase the gap (30) and in a second direction to cause the control means (36) to effect relative movement of the first and second components to decrease the gap (30).

Abstract: A component for a gas turbine engine having at least one surface, that has been treated by ultrasonic hammer peening so as to provide a region of deep compressive residual stress in the treated region.

Abstract: A gas turbine engine exhaust nozzle arrangement for the flow of exhaust gases therethrough between an upstream end and a downstream end thereof comprising a nozzle and a plurality of tabs which extend in a generally axial direction from a downstream portion of the nozzle wherein the nozzle further comprises an actuation mechanism capable of moving the tabs between a first deployed position, where the tabs interact with a gas stream to reduce exhaust noise thereof, and a second non-deployed position, where the tabs are substantially aerodynamically unobtrusive.

Abstract: A seal (40) provides sealing between two pressure zones (60, 62) and a rotating and non-rotating member (42, 52) by providing a first sealing member (46) between two seal lands (48, 50). A second seal (64) is mounted between the non-rotating member (52, 58) and one of the seal lands (50, 66) so as to control pressure around the seal lands (48, 50).

Abstract: A component for a gas turbine engine having at least one surface, that has been treated by ultrasonic hammer peening so as to provide a region of deep compressive residual stress in the treated region.

Abstract: A method of prestressing a component (30) includes the use of an electrical discharge or current to produce a plasma (39) within a medium (32) located adjacent the component (30). The plasma generates a shock wave which impacts a surface of the component to produce a region of compressive residual stress within the component.

Abstract: A control arrangement (34) for controlling the size of a gap (30) between first and second components. The control arrangement comprises first magnet means (38) to be provided on the first component, and second magnet means to be provided on the second component. The first and second magnet means are in magnetic interaction with each other across the gap (30) and the arrangement further includes control means (36) to control the size of the gap (30) the first magnet means (38) is a moveable in a first direction to cause the control means (36) to effect relative movement of the first and second components to increase the gap (30) and in a second direction to cause the control means (36) to effect relative movement of the first and second components to decrease the gap (30).

Abstract: An apparatus for detecting pressure in a hollow fan blade of a turbofan gas turbine engine comprises a magnetostriction transducer arranged in a sub chamber of the fan blade which is interconnected to a main chamber. A magnetic coil is arranged in the fan casing of the turbofan remote from the fan blade, and an alternating current is supplied from a supply to the magnetic coil to produce an alternating magnetic field. The alternating magnetic field causes the magnetostriction transducer to generate vibrations in the fan blade and the magnetostriction transducer. A magnetic search coil detects changes in the magnetic field, which corresponds to the vibrations, and a processor analyses the vibrations to determine if there has been a change in the resonant frequency of the vibrations which is indicative of a change in the pressure in the fan blade. The processor supplies a signal to a display or to an alarm. The change in the pressure is indicative that the fan blade is cracked and needs replacing.