Abstract: The invention provides a metallic foam material with better mechanical properties than known foamed materials, and a method of making such a material. Although known foamed metals are light in weight, and sandwich structures formed of such materials can be formed into structural components, the tendency for the structure to crush and fracture under compressive loading, with consequent crack propagation, limits their use in applications in which the integrity of the component is important. The invention addresses this problem by providing a fibre-reinforced foam that combines the tensile strength of a high strength fibre such as carbon fibres with the impact resistance (through crushing and deformation) of metallic foam. The metal foam imparts a greater strength to the carbon-fibre-reinforced plastics (CFRP) part of the structure than it would have by itself. Under tensile loads, the fibre reinforcement gives the metallic foam enhanced strength and low creep.

Abstract: A balancing assembly for a rotor comprises a mass, a displacement arrangement for displacing the mass along a guide arrangement. The guide arrangement extends circumferentially and the displacement arrangement can move the mass circumferentially around the principal axis of the rotor during rotation of the rotor.

Abstract: A rotor stage (13, 14, 15, 17, 18, 19) of a gas turbine engine (10) comprises an annular retaining plate (38) capable of preventing axial movement of blades (30). The retaining plate (38) is secured to the disc (32) via a bayonet arrangement (49). A locking assembly (48) is provided to prevent relative rotation between the disc (32) and the retaining plate (38). The locking assembly (48) comprises a locking plug (50) configured in a generally Y-shaped cross section having a channel portion defined by arms (56), which engage upstream and downstream of the retaining plate (38) and a leg part (58) configured to span between bayonet parts (40 and 42), thereby preventing relative rotation between the disc (32) and the retaining plate (38). The assembly (48) further comprises a securing plate (52) configured to span between circumferentially adjacent castellations (40) thereby preventing the locking plug (50) disengaging the disc (32) and retaining plate (38).

Abstract: A lubrication system comprises a reservoir for lubricant, lubricant delivery means to deliver lubricant to at least one component to be lubricated, an injector associated with each component, a control system to control the opening and closing of each injector and scavenge means to remove surplus lubricant from around each component and return it to the reservoir. Each injector comprises a pulsative injector, controlled by the control system to deliver lubricant to its associated component in a series of discrete pulses. In a preferred embodiment both the delivery of oil to each component and the scavenging of oil from each component are controlled in response to sensed conditions of that component.

Abstract: A structural member comprises a main body formed from a cellular material. The structural member may be a casing for a rotary assembly e.g. a fan of a gas turbine engine. The main body may incorporate strengthening ribs and conduits and may have a random or graduated arrangement of different sized cells forming the cellular material. A recess may be defined on the radially inner face of the main body to receive an abradable material suitable for forming a seal with the blades of the fan.

Abstract: A blade arrangement 31 includes an array of radially extending blades 20, which may for example comprise a fan of a gas turbine engine for an aircraft. The blades 20 are mounted for rotation about a central axis X-X. The blade arrangement 31 further includes a damping arrangement 32 comprising means 34 for inducing an axi-symmetric magnetic field whose axis of symmetry coincides with the central axis X-X of rotation of the blades 20. The damping arrangement 32 is configured such that when the magnetic field is induced, any movement of the blade 20 other than pure rotation about the central axis results in the magnetic field causing a force to be exerted on the blade 20, the force resisting such movement. The damping arrangement may be provided with means for inducing the magnetic field only when there is an increased likelihood of vibration of the blades, for example when a foreign body has entered the air intake of the engine.

Abstract: A sensor 30 has first and second electrodes 32A, 32B spaced to define a gap 34 therebetween. The electrodes are formed on a substrate which can be covered with a film of material. The width of the gap 34 is different at different positions on the electrodes 32. This results in a sensing characteristic which can be made substantially linear, without sensitivity varying with film thickness, which arises from the use of a constant gap width. The sensor can be used to detect or measure film or liquid layer thickness, or solid material deposition.

Abstract: A sensor 10 comprises an array of electrostatic sensor elements 12, each centred at a respective sensing position 14. Each element produces a respective output signal at 16. The outputs 16 can be used to drive respective pixels of a display. This allows an image to be created to represent the electrostatic charge distribution across the region to which the sensor is directed.

Abstract: A leakage drain (30) is used to provide an indication that leakage of a fluid has occurred within an engine. Previously such leakage was detected by visual inspection of a retained drop at the outlet of a drain. With the present invention a sensor arrangement comprising electrodes (33, 34; 133, 134) is located within or about the leakage drain (30) whereby leakage fluid creates a film across those electrodes. Relative presence or absence or thickness of film causes variation in a detected electrical response (capacitance, reactance, resistance or impedance) and this variation is utilised in order to determine whether fluid leakage has occurred. Additionally by time of flight analysis using electrostatic sensors (35, 36; 135, 136) it is possible to determine fluid flow rate. By analysis at different incident frequencies a characteristic response for a particular type of leakage fluid is obtained. Thus, it is possible to deduce the type of leakage fluid as well as the rate of leakage.

Abstract: A structural member comprises a main body formed from a cellular material. The structural member may be a casing for a rotary assembly e.g. a fan of a gas turbine engine. The main body may incorporate strengthening ribs and conduits and may have a random or graduated arrangement of different sized cells forming the cellular material. A recess may be defined on the radially inner face of the main body to receive an abradable material suitable for forming a seal with the blades of the fan.

Abstract: A Method and Machine for Shaft Imbalance Determination Correcting unbalance with regard to rotors (11, 101) and shafts is important in order to improve performance of those rotors (11, 101) or shafts within a practical machine or engine. Previously, result orientated iterative balancing of the rotor or shaft has been achieved in which mass has been added or possibly intrusive and distorted adjustments in drag and stiffness presented through bearings or alteration of the rotor (11, 101) itself have been utilised to improve rotor balance performance. In the present invention, a dynamic bearing 13 is utilised in order to provide force components with some components in phase with rotor deflection in order to simulate negative stiffness and/or some force components in phase with rotor velocity in order to simulate negative drag upon the rotor (11, 101).

Abstract: A fluid monitoring arrangement 1 for an engine is operated in accordance with a method whereby nuclear magnetic resonance (NMR) interrogation of the fluid flow 3 it is possible to determine whether appropriate fluids and additives are being utilised as well as whether potential detrimental actions occur such as engine wear and carbonisation through particulate components within the flow 3. Generally, an expected signal response from the fluid flow 3 is determined and the actual signal response compared in a comparator 8 with that expected signal response. Divergence in the actual signal response and in particular with regard to its profile is identified and an indication provided in a display 10 with regard to the potential coolant of such divergence. Normally, a reference library 11 is provided of expected signal responses for comparison in the comparator with the actual signal responses.