Abstract: A rotor having a bladed disc and for use in a fluid flow machine has plates extending between and supported by the blades to protect the disc rim from erosion and foreign object damage and also, when the rotor is a gas turbine, to protect the disc rim from the heating effects of high temperature gasses. The plates are held between ridges on the blade faces.

Abstract: A program-controlled heat management system for an aircraft's bypass gas turbine (turbofan) engine installation, in which the engine's fuel system is put into direct heat exchange relationship with the engine's own oil system, and with an engine-driven electrical generator's oil system, by means of respective fuel/oil heat exchangers and also into selective indirect heat exchange relationship with a variable proportion of the engine's bypass air means of an engine oil/air heat exchanger. The fuel system is switchable between four different fuel flow configurations in order to vary the heat flows between the fuel system and the oil systems, two of the fuel flow configurations also involving recirculation of fuel from the engine's fuel system to a fuel tank in the aircraft wing in order to put the fuel system into selective heat exchange relationship with the tank and hence with the airstream passing over the wing.

Abstract: A hydraulic seal is formed in the annular space 16 between two coaxial drive shafts 12 and 14. The seal is assembled with the two shafts in situ. An annular resilient seal member 30, which has an outer diameter which is larger than the inner diameter of the outer shaft 12, is deformed so that it can be passed through the annular space 16. The resilient seal member 30 is positioned in a channel 18 in the inner surface of the outer shaft 12. Once in the channel 18 the resilient seal member 30 returns to its original shape. The resilient seal member 30 is located between a pair of annular flanges 22 and 26 on the end of a pair of elongate members 20 and 24 of annular cross-section. The resilient seal member 30 protrudes into the channel 18 so that in operation it is partially immersed in a fluid 32 in the channel 18 to form the hydraulic seal.

Abstract: There is provided a rotor arrangement comprising primary blades 16 mounted on a support disc 15 and secondary blades 18 mounted on a support disc 17. The secondary blades are disposed between respective primary blades with some axial overlap. The set of secondary blades is movable relative to the set of primary blades so that each secondary blade can be moved between end positions abutting the associated pair of primary blades.

Abstract: A ceramic shell mould (70) for casting a single crystal turbine blade comprises a plurality of article portions, (72), each of which has an article chamber (74) for defining the shape of a turbine blade, a plurality of selector portions (76), a plurality of starter portions (80) and a runner portion (84). The runner portion (84) comprises a first subsection (86) which has a central axis (87) arranged parallel to, and spaced from, the central axes (73) of the article portions (72) and a plurality of second subsections (90) which interconnect the first subsection (86) with the article portions (72). The second subsections (90) are arranged to make an acute angle with the first subsection (86) of the runner portion (84) and with the starter portions (80) so that the second subsections (90) may bend to allow relative movement between the first subsection (86) and the starter portions (80) to prevent the cast turbine blades falling off the mould.

Abstract: A twin-hulled ship is powered by a gas turbine engine in each hull, the engine being located near the waterline in vertical alignment with a position outboard of the superstructure's internal sidewall, but preferably inboard of the superstructure's external sidewall. This is facilitated by the outward bulge of the hull relative to the superstructure's external sidewall. An air inlet filter bank is mounted in the side of the superstructure sufficiently far above the waterline to avoid swamping. Air intake ducting leads from the filter bank to the engine, and exhaust ducting leads from the engine to an exhaust outlet at a higher level than the filter bank. This arrangement enables intrusion of intake and exhaust ducting into the main loading deck space to be avoided while minimizing deviation of intake and exhaust ducting from a straight line path.

Abstract: A special type of flange ring (201) for making bolted flanged joints between axially consecutive component parts of hollow fabrications, such as gas turbine aero engine casings (210). Each flange joint face (206) has, at its radially inner circumference, a radially extending sealing land or flat (216), the remainder of the flange joint face comprising, when in the unstressed condition, a frustoconical surface (209) inclined at a small angle (c.degree.) to the radial plane (207) of the sealing flat (216). The frustoconical surface (209) is drawn into contact with a complementary joint surface (208) when the bolts (204) are tightened. The flange rear face (212) is parallel to the frustoconical surface (209). This configuration creates a joint having a large line reaction force along the sealing land (216), thereby providing efficient sealing against internal pressure even when tension forces in the casing (210) are present. Alternative embodiments are described.

Abstract: To control unsteady motion phenomena in turbomachines, it has been proposed to employ an active control system to modify the flow conditions. In the present invention, the modification is effected by devices mounted in a bullet or nose bullet at the entry to a rotor of the turbomachine.

Abstract: A stack of titanium sheets are placed between a pair of pressurisable chambers in a vacuum chamber. One of the mating surfaces of each pair of mating surfaces has had a stop off material applied in a desired pattern to prevent diffusion bonding. A pump evacuates the vacuum chamber and heaters heat the stack to evaporate volatile binders from the stop off. When all the binder has been removed the stack is heated and the pressure in the pressurisable chambers is increased to cause a pair of resilient members to apply pressure on the stack to diffusion bond the sheets together. The volatile binder is removed quickly and oxidation of the titanium is prevented during baking out of the binder. The integral structure is then heated and internally pressurised to superplastically form one of the sheets to produce an article of predetermined shape. No welding of the sheets before bonding is required.

Abstract: A cooling air pick up for use in a gas turbine engine includes a cooling air duct incorporating a diffuser to maximize the cooling air pressure. The entry orifice of the pick up duct is formed in the leading edge of a flow vane in the interior of a flow passage downstream of the engine compressor section.

Abstract: A ducted fan gas turbine engine spinner is so configured so as to be generally outwardly flared at its downstream end. The flared portion provides a decrease in the local axial velocity of the air flow over the spinner. This in turn leads to the reduction or elimination of choking in the radially inner region of the fan of the engine.

Abstract: Turbulence in the boundary layer of a flow of air across a surface is controlled by sucking air from the surface. A plurality of turbulence detectors are located in the surface downstream of apertures provided in the surface. The apertures are connected to a suction pump. Air is sucked through the apertures until the air flow of the most downstream of the detectors is non-turbulent.

Abstract: An air seal is disposed between high and low pressure zones and includes an annular static arm and coaxial annular sealing arm which rotates relative to the static arm. The static arm, is scalloped to form a series of cavities and the sealing arm is formed with angled through holes opposite the cavities. A seal is provided between the static arm and the sealing arm. In use, a ram pressure rise is generated in the holes by the rotation of the sealing arm and the pressure rise creates a flow of air which offsets the leakage past the seal.

Abstract: A ceramic fibre reinforced metal rotor with integral rotor blades is manufactured using a continuous strip of unidirectional ceramic fibres in a metal matrix. The continuous strip of ceramic fibres in the metal matrix is cut into a plurality of separate pieces of predetermined length. The separate pieces of ceramic fibres in the metal matrix are arranged alternately in a spiral, with separate pieces of unreinforced metal matrix in adjacent abutting relationship to form a ring which has a plurality of laminations. The ring of laminations of metal matrix composite pieces and unreinforced metal matrix pieces are arranged between an inner and an outer metal ring to form an assembly. The assembly is consolidated by hot isostatic pressing using radially applied pressure. The separate pieces of metal matrix composite provide compliance to reduce breaking or buckling of the fibres, and the pieces of unreinforced metal matrix prevents damage spreading between laminations.

Abstract: A perforated sheet for the promotion of film cooling a gas turbine engine comprises two separate layers of laminate material which are placed in superposed abutting relationship. The first layer has a plurality of apertures of given cross-sectional area therein. The second layer also has a plurality of apertures therein which have larger cross-sectional areas than the corresponding apertures in the first layer. The apertures in the first layer are in fluid communication with the apertures in the second layer to form passageways through the perforated sheet. These passageways permit a cooling flow of fluid to pass through the perforated sheet so it can be discharged as a cooling fluid film along the inner surface of the perforated sheet. The apertures in each layer are independently formed to produce the passageways. The apertures can easily be machined to the desired size, shape, and angle to optimize the cooling film effectiveness for any particular application.

Abstract: Small cooling holes, e.g. 0.25-0.9 mm diameter, in cast hollow turbine blades are provided by delivering successive pulses of laser energy to the surface of the blade until penetration of the blade is complete. By leaving the ceramic casting core in situ within the blade during drilling, the laser beam is prevented from striking through to the far wall of the cavity defined by the ceramic core within the blade. The ceramic core is subsequently removed by leaching techniques common to the art.

Abstract: A blade clearance control apparatus (46) for a gas turbine engine (10) comprises a series of segments (42) which define a casing in the rotor path of high pressure shroudless turbine blades (30).The segments (42) are attached to plates (78) having surfaces co-operating with chordal lengths (74) of a number of pressure tubes (68) which are located in a frame (46). The application and release of pressure to the pressure tubes (68) causes the segments (42) to move between inner and outer positions in order to control clearance X between the tips of blades (30) and the segments (42).

Abstract: A light guide has a window through which radiation passes to a detector. The light guide is provided with a housing which defines a duct through which a flow of cooling fluid passes. The duct is arranged so that a proportion of the fluid flow passes over the external surface of the window to prevent deposition of contaminants thereon. A circumferential shield extends around the window to control the flow of radiation therethrough. The circumferential shield has a curved radial recess therein which imparts a rotational component of velocity to the flow of fluid passing over the surface of the window to promote cooling of the shield. The shield is further provided with an annular internal step which prevents radiation reflected from the inner wall of the shield passing through the shield.

Abstract: A shrouded aerofoil assembly such as a turbine rotor for a gas turbine engine has a multiplicity of blades with tip shrouds circumferentially distributed around a rotor disk. Inevitably, in use, the assembly vibrates and must be designed so the potentially most dangerous vibratory modes occur outside the engine speed range. The proposed arrangement has a number of neighbouring blades sharing a common shroud segment. Adjacent shroud segments are interlocked by Z-notch abutments. Blade assemblies have sufficient pre-twist load to maintain frictional contact in the interlocks over the speed range to maintain damping constraints.

Abstract: This invention provides an apparatus for and method of manufacturing a brush seal. The apparatus comprises an annular former 22 having a radially outer 24 and a radially inner 30 portion radially separated from each other by an amount G and held relative to each other by locating means 32, and further includes a travelling wire electro discharge machining device and a guide tube. A brush seal 10 is wound onto the former in the usual manner and the filament material 38 cut in the region of the gap G by the travelling wire 44. The wire is inserted between the filaments by first inserting a tube 52 therebetween and passing the wire 44 therethrough. Machining of the filament material is achieved by traversing the wire around the gap G.