Abstract: A blade arrangement (22) comprises an aerofoil (26) and a mounting support (28) to mount the blade arrangement to a disc. The aerofoil (26) is supported on the mounting support (28). The aerofoil (26) comprises a plurality of elongate aerofoil portions (34) arranged adjacent one another to provide the aerofoil.

Abstract: An aerofoil 31, 43, 56 is provided by layers of material with at least one layer of the material being relatively stiff while other layers of material are less dense but are subject to less stress within the aerofoil. Thus, by judicious positioning of the stiffer layers of material an effective operational aerofoil is achieved, with the other layers of material having a lower stiffness but also lower mass so that the overall mass of the aerofoil is reduced. It will be understood by appropriate positioning of the layers of material it is possible to tune the aerofoil for deformation and vibrational response effects, particularly under impact loading from bird strikes etc.

Abstract: A blade for a gas turbine engine includes a root portion, an aerofoil portion and a transition portion between the root portion and the aerofoil portion. The aerofoil portion and the transition portion are defined by first and second wall members, the first and second wall members being secured together in the transition portion and each having an outer surface. The outer surface of at least one of the first and second wall members is generally concave in the transition portion in a radial direction of the blade.

Abstract: A fan blade containment assembly (38) for a turbofan gas turbine engine (10) comprises a cylindrical, or frustoconical, casing (40) arranged to surround an arrangement of fan blades (26). At least one hollow tubular member (66) is arranged radially within and secured to the casing (40) and the at least one hollow tubular member (66) contains a filler material (68). The at least one hollow tubular member (66) extends circumferentially. The hollow tubular member (66) is helical and the axial spacing between the adjacent turns of the tubular member (66) varies and the density of the filler material (68) varies in order to match the severity of the impact expected at each axial location along the casing 40 of the fan blade containment assembly (38).

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: A stage of fan aerofoils (10) lies within a fan cowl (12). The fan duct (16) is defined in part by a hard casing (14) that in turn surrounds aerofoils (10). Hard casing (14) includes wedge members (26) that fill the annular gap between ring (14) and an outer ring (20). In the event of an aerofoil (10) breaking off, the hard ring (14) and wedges (26) absorb sufficient of the kinetic energy expended by the broken aerofoil (10), as to prevent it passing through outer ring (20) on to the fan cowl (12).

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: The angular nature of corners 3 to roots 2 of a conventional blade 1 used in a gas turbine engine has resulted in relatively thick fan casings in order to contain any blade fragments from these corners 3 as a result of blade failure. By angling the end face 26 of the root 22 such that it is nearer to perpendicular to an axis of curvature 27 for a blade 21 the corners 23 are reduced in their angular nature. In such circumstances the potential for penetration of a fan casing through impingement with such corners 23 is reduced and the fan casing thickness can more confidently be thinned reducing overall weight. Furthermore by appropriate profiling of an aerofoil 24 adjacent to the front and trailing edges 20 of the aerofoil about the root 22 and face 26 further reductions in angular parts of the blade can be achieved.

Abstract: A blade arrangement (22) comprises an aerofoil (26) and a mounting support (28) to mount the blade arrangement to a disc. The aerofoil (26) is supported on the mounting support (28). The aerofoil (26) comprises a plurality of elongate aerofoil portions (34) arranged adjacent one another to provide the aerofoil.

Abstract: A blade for a gas turbine engine includes a root portion, an aerofoil portion and a transition portion between the root portion and the aerofoil portion. The aerofoil portions and the transition portion are defined by first and second wall members, the first and second wall members being secured together in the transition portion and each having an outer surface. The outer surface of at least one of the first and second wall members is generally concave in the transition portion in a radial direction of the blade.

Abstract: An aerofoil 31, 43, 56 is provided by layers of material with at least one layer of the material being relatively stiff whilst other layers of material are less dense but are subject to less stress within the aerofoil. Thus, by judicious positioning of the stiffer layers of material an effective operational aerofoil is achieved, with the other layers of material having a lower stiffness but also lower mass so that the overall mass of the aerofoil is reduced. It will be understood by appropriate positioning of the layers of material it is possible to tune the aerofoil for deformation and vibrational response effects, particularly under impact loading from bird strikes etc.

Abstract: Two metal blocks (50, 52) are welded to respective metal sheets (30, 32) to form sealed assemblies. The sealed assemblies are then diffusion bonded together to form two metal preforms (54, 56). The thick ends (36) and (40) of the metal sheets (30, 32) and the metal blocks (50, 52) are hot formed so that a continuation of the plane X of the first surfaces (42, 46) of the metal sheets (30, 32) extends through and across the metal blocks (50, 52). The metal preforms (54, 56) are machined to remove the portion of the metal blocks (50, 52) extending above the first surfaces (42, 46) of the metal sheets (30, 32) respectively. The metal preforms (54, 56) and a metal sheet (58) are assembled into a stack (64). The metal preforms (54, 56) and the metal sheet (58) are diffusion bonded together and then superplastically formed to produce a hollow fan blade (10). The method enables thinner metal workpieces with better microstructure to be used and increases the yield of metal workpieces.

Abstract: A fan rotor assembly (30) for a gas turbine engine (10) comprises a fan rotor (32) and a plurality of radially extending fan blades (34). Each fan blade (34) has a root (64) which is retained in a corresponding groove (54) in the periphery of the hub (54) of the fan rotor (32). Each fan blade root (64) comprises four axially spaced root portions (66, 68, 70 and 72) which locate in a corresponding number of axially spaced groove portions (56, 58, 60 and 62). The flanks (94, 98) of two of the root portions (66, 70) are arranged at an angle to the axis of the fan rotor (32) and the flanks (96, 100) of the other two root portions (68, 72) are arranged at an angle in the opposite sense. The flanks (74, 76, 78 and 80) of the groove portions (56, 58, 60 and 62) are arranged at the same angle as the flanks (94, 96, 98 and 100) of the corresponding root portions (66, 68, 70 and 72). The arrangement provides improved retention of the fan blades (34) and reduces the weight of the fan blades (34) and fan rotor (32).

Abstract: A rotor for a ducted fan gas turbine engine includes a rotor disc on which a number of circumferentially spaced apart blades are mounted. Wall members are positioned to bridge the space between adjacent blades. The wall members correspond in profile with the blades adjacent thereto. A seal is mounted on a side face of each wall member and is bonded to a flexible mounting which is bonded itself to the wall member. The flexible mounting has elastic properties so as to allow the seal to deflect relative to the wall member under centrifugal loading during operation.