Abstract: An aerofoil 26 for a gas turbine engine (10, FIG. 1) comprises a cavity 38, a cellular material 42 located in the cavity 38 for stiffening the aerofoil 26, and a vibration damping medium 44 located in the cavity 38 for damping the aerofoil. The cellular material 42 is preferably a metal foam bonded to the inner surface 34a, 36a of the hollow aerofoil 26, and the vibration damping medium 44 is preferably a viscoelastic material. Various methods for fabricating the aerofoil 26 are also described.

Abstract: An aerofoil 26 for a gas turbine engine (10, FIG. 1) comprises a cavity 38, a cellular material 42 located in the cavity 38 for stiffening the aerofoil 26, and a vibration damping medium 44 located in the cavity 38 for damping the aerofoil. The cellular material 42 is preferably a metal foam bonded to the inner surface 34a, 36a of the hollow aerofoil 26, and the vibration damping medium 44 is preferably a viscoelastic material. Various methods for fabricating the aerofoil 26 are also described.

Abstract: Blade assemblies are provided in a number of forms. These blade assemblies may have blades secured to disks (blisk), rings (bling) and drums (blum). The blades and/or the rotor elements formed by these rings, drums or disks can fragment and it is necessary to contain such fragments within a casing. Impact energy has a significant effect upon the necessary thickness of the casing to ensure containment. By providing blades as well as rotor elements which incorporate discontinuities which provide flexing under impact, energy is absorbed prior to further fragmentation upon impact engagement with a casing surface; flexing is about the discontinuity. In such circumstances casings may be thinner and therefore significant weight savings achieved with regard to aircraft incorporating gas turbine engines having blade assemblies with discontinuities.

Abstract: International regulations for aerofoils within gas turbine engines require the safe containment of a released aerofoil. The blade fragments must be contained within an engine casing. Smaller fragments will generally be easier to contain within the casing and therefore reduce the weight of that casing. However introducing lines of weakness may result in cavities and holes which are subject to moisture ingress and problems associated therewith. By providing a root section which incorporates a core having shear surfaces, blades can be designed which in normal use are subject to compressive loads and remain operational, but when subject to impact loads or bending forces create tension forces which cause fragmentation along the shear surfaces after initial energy losses by slippage. By providing the shear surfaces in cores their location is encapsulated avoiding problems with moisture ingress.

Abstract: A fan blade for a gas turbine engine has an aerofoil part and a root part. The root part includes a root former; the root former 18 includes a zone of weakness, which reduces the ability of the root part to withstand an impact force. Thus, in an impact situation in which the fan blade has separated from the fan rotor and the fan blade has itself separated into fragments, the root part will fracture or buckle more easily than would be the case with conventional arrangements. This will lower the impact force of the root part upon the fan casing, thus permitting the fan casing to be designed to withstand lower impact forces. The fan casing can therefore be made lighter, and cheaper, than in conventional arrangements.

Abstract: An annulus filler (101) is provided for mounting to a rotor disc (102) of a gas turbine engine and for bridging the gap between two adjacent blades attached to the rotor disc (102). The annulus filler (101) has an outer part (106) which defines an airflow surface for air being drawn through the engine, and a separate, support part (105) which is connectable to the outer part (106) and to the rotor disc (102) to support the outer part (106) on the lo rotor disc (102). The outer (106) and support parts (105) are configured to allow a procedure for mounting the annulus filler (101) to the rotor disc (102). In a first step the support part (105) is connected to the rotor disc (102) without the outer part (106), and in a subsequent second step the outer part (106) is connected to the support part (105).

Abstract: An aerofoil (35) for example a fan blade (26) comprises a leading edge (36), a trailing edge (38), a concave pressure surface extending (40) from the leading edge (36) to the trailing edge (38) and a convex suction surface (42) extending from the leading edge (36) to the trailing edge (38). The aerofoil (35) comprises a metal foam (50) arranged within a cavity defined by metal workpieces (52, 54). The metal foam (50) of the aerofoil (26) ideally has a density of less than 1g/cm3, is cheaper to manufacture and has improved fatigue behaviour and impact capability.

Abstract: Reduction in weight is an important factor with respect to turbine engines used in aircraft. Blades (20) used in such turbine engines may fragment such that it is necessary that the containment casing (42) can resist such fragmentation. Root portions of blades are generally less deformable and therefore require conventionally more robust containment casings. Use of super plastically formed blades allows provision of slots (4, 14, 24, 46) in the root portion which facilitate fragmentation and deformation by the root portion under impact reducing the necessity for greater reinforcement of the containment casing. The slots (4, 14, 24, 24, 46) are created in a membrane utilised for web reinforcement of the blade rather than through intrusive drilling and cutting processes which may introduce machining stresses into their creation and potential tool loss within the high value blade.

Abstract: With regard to components it is necessary to test specimens of materials in order to determine acceptability for objective component performance. Previously such testing generally involved fixing and clamping of the test specimen which produced artificial stressing conditions. By providing a specimen component typically in the form of an elongate member 2 which is suspended between mounting ends 3 a combination is provided which has inertia. In such circumstances when a projectile impacts upon the elongate member that elongate member flexes and deforms and this deformation can be monitored for testing purposes. The projectile 4 is arranged to have a relatively facile compliant nature upon impact with the component 2 such that there is no local stressing of the component whilst suspending the mounting ends substantially avoids clamp resilience distorting objective or realistic stressing conditions.

Abstract: Aerofoils (22) of a gas turbine engine are provided with a coating (34) or filler (44) of viscoelastic material. As ice accretes on the aerofoils (22) during operation, the resulting aerodynamic stability imbalance induces vibration in the aerofoils (22). The viscoelastic material (34, 44) damps this vibration, and in so doing generates heat, which melts the ice away from the aerofoils (22). Heat-conducting members conduct the heat to regions of the component in which ice accretion is to be prevented. Alternative embodiments are described in which the pseudoelastic behaviour of a shape memory alloy (56), or eddy currents arising from the rotor blades' rotation in an axisymmetric magnetic field, are used as sources of heat.

Abstract: The invention provides a coating on a polymeric substrate forming a non-porous print receptive layer on the polymeric substrate, printability, thermal conductivity.

Abstract: With regard to hollow blades for turbine engines, it will be understood there is a problem with respect to percussive impact resulting in excessive distortion of the blade as well as potential failure as a result of blade tip bulging. By provision of ridges 107, 207, 307 which coincide and engage each other under impact, the extent of impact deformation is limited as well as a result of the narrowing between the ridges, a reduction in the possibility for fragmentary insert movement to bulge the cavity towards the tip 102, 202, 302 of a blade 100, 200, 300.

Abstract: A blade (10, FIG. 1) for a gas turbine engine includes an aerofoil portion (12, FIG. 1) and a root portion 14 defined by concave and convex walls 16, 18 having opposing inner surfaces 16a, 18a. A reinforcing member 20 is located between the concave and convex walls 16, 18 and is bonded to the inner surfaces 16a, 18a thereof, and the root portion 14 includes an unbonded region 24a, 24b in which the reinforcing member 20 contacts an inner surface 16a, 18a of one of the concave and convex walls 16, 18 but is not bonded thereto.

Abstract: An aerofoil (35) for example a fan blade (26) comprises a leading edge (36), a trailing edge (38), a concave pressure surface extending (40) from the leading edge (36) to the trailing edge (38) and a convex suction surface (42) extending from the leading edge (36) to the trailing edge (38). The aerofoil (35) comprises a metal foam (50) arranged within a cavity defined by metal workpieces (52, 54). The metal foam (50) of the aerofoil (26) ideally has a density of less than 1g/cm3, is cheaper to manufacture and has improved fatigue behaviour and impact capability.

Abstract: An aerofoil blade for a gas turbine engine, the blade having a metallic core defining a number of cavities that contain a foamed material. The cavities are shaped such that the force of an impact on one surface of the blade is dissipated through the foam and transmitted to the metallic core. A fibrous internal containment device allows the blade to fragment progressively thereby spreading the load imparted by the blade to a casing should the blade fragment upon impact.

Abstract: A compressor blade (26) comprises an aerofoil (36) and a root (38). The aerofoil (36) comprises a concave wall (40) extending from a leading edge (44) to a trailing edge (46) and a convex wall (42) extending from the leading edge (44) to the trailing edge (46). The aerofoil (36) defines at least one internal chamber (48). The root (38) is connected to the aerofoil (36) and the root (38) has a base (50) remote from the aerofoil (38) and at least one aperture (52) extends from the base (50) to the at least one internal chamber (48) in the aerofoil (36). The dimensions, shape and position of the least one aperture (52) are selected such that the root (38) is deformable. This reduces the weight of the containment region of a fan casing (28).

Abstract: Percussive impacts due to bird strikes upon the hollow fan blades 20 are a well known problem. These percussive impacts not only deform previous fan blades but also reduce their stiffness. In accordance with the present invention, hollow fan blades 20 incorporate a cavity 23 within which, a matrix 24 with embedded expandable elements 25, is located. Thus, upon a percussive impact these expandable elements 25 are released in order to create an internal pressure within the cavity 25 which acts outwardly in order to relieve deformation and also stiffen the blade 20 as a result of the over pressure within the cavity 23.

Abstract: With regard to hollow blades for turbine engines, it will be understood there is a problem with respect to percussive impact resulting in excessive distortion of the blade as well as potential failure as a result of blade tip bulging. By provision of ridges 107, 207, 307 which coincide and engage each other under impact, the extent of impact deformation is limited as well as a result of the narrowing between the ridges, a reduction in the possibility for fragmentary insert movement to bulge the cavity towards the tip 102, 202, 302 of a blade 100, 200, 300.

Abstract: A compressor blade (26) comprises an aerofoil (36) and a root (38). The aerofoil (36) comprises a concave wall (40) extending from a leading edge (44) to a trailing edge (46) and a convex wall (42) extending from the leading edge (44) to the trailing edge (46). The aerofoil (36) defines at least one internal chamber (48). The root (38) is connected to the aerofoil (36) and the root (38) has a base (50) remote from the aerofoil (38) and at least one aperture (52) extends from the base (50) to the at least one internal chamber (48) in the aerofoil (36). The dimensions, shape and position of the least one aperture (52) are selected such that the root (38) is deformable.

Abstract: Percussive impacts due to bird strikes upon the hollow fan blades 20 are a well known problem. These percussive impacts not only deform previous fan blades but also reduce their stiffness. In accordance with the present invention, hollow fan blades 20 incorporate a cavity 23 within which, a matrix 24 with embedded expandable elements 25, is located. Thus, upon a percussive impact these expandable elements 25 are released in order to create an internal pressure within the cavity 25 which acts outwardly in order to relieve deformation and also stiffen the blade 20 as a result of the over pressure within the cavity 23.