Abstract: A rotor blade has a tip with an outer face including at least two channels which each extend to an outlet in the vicinity of the trailing edge. Accordingly, gas leakage around the tip must cross at least three walls, at least in the vicinity of the uncovered turning region near the trailing edge of the blade. Leakage gas entering the channels will tend to create a vortex and pass along the channel to the outlet.

Abstract: A shroud segment for a turbine stage of a gas turbine engine forms an endwall for the working gas annulus of the stage. The segment also provides a close clearance to the tips of a row of turbine blades which sweep across the segment. In use, a mainstream flow of the working gas passes through the passages formed between adjacent turbine blades. The segment has a plurality of cooling holes and respective air feed passages for the cooling holes. The cooling holes are distributed over that part of the gas-washed surface of the segment which is swept by the blade tips. The cooling holes deliver, in use, cooling air which spreads over the gas-washed surface. The feed passages are configured such that the delivered air has swirl directions which are co-directionally aligned with the swirl directions of the mainstream flow at the segment.

Abstract: A shroud segment for a turbine stage of a gas turbine engine forms an endwall for the working gas annulus of the stage. The segment also provides a close clearance to the tips of a row of turbine blades which sweep across the segment. In use a leakage flow of the working gas passes through the clearance gap between the blade tips and the segment. The segment has a plurality of cooling holes and respective air feed passages for the cooling holes. The cooling holes are distributed over that part of the gas-washed surface of the segment which is swept by the blade tips. The cooling holes deliver, in use, cooling air which spreads over the gas-washed surface. The feed passages are configured such that the delivered air opposes the leakage flow of the working gas.

Abstract: Dampers (56, 76, 96) are utilized with regard to mounting arrangements (50, 70, 90) in gas turbine engines (10) in order to facilitate cooling. It is known to provide slotted upper surface or cottage roof dampers to enhance cooling effect. However, cooling efficiency cannot be optimized and improving cooling effectiveness particularly between the parts of a mounting arrangement can be difficult without detrimental reductions in overall efficiency of a gas turbine engine (10) incorporating such a mounting. By provision of impingement jets (54, 75, 94) which extend through the damper (56, 76, 96) into slots (51, 71, 91) which define an upper surface of the damper (56, 76, 96) improvements in cooling efficiency can be achieved. The slots (51, 71 91) are typically closed to reduce requirements with respect to pressure differentials. However, open ended slots (51, 71, 91) with impingement jets (54, 74, 94) can also be provided.

Abstract: A turbine blade (40) for a gas turbine engine has an aerofoil portion (42) extending from a root (48) to a tip (54). The tip (54) carries winglets (56, 58). A gutter (62) extends across the tip (54) to entrain gas leaking around the tip (54) (over tip leakage). The aerofoil portion (42) has a mean camber line and the gutter (62) has a centre line. In the examples described, the conditions that (a) the mean camber line and the centre line coincide at the exit when viewed from the tip towards the root, and (b) the mean camber line and the centre line are parallel at the exit when viewed as aforesaid, are not both fulfilled.

Abstract: A rotor blade 40 for a gas turbine engine has an aerofoil portion 42 from a root 48 to a tip 54. In use, combustion gas may leak over the tip 54 from the pressure face 52 to the suction face 50. A gutter 62 extends across the tip 54 to entrain any over tip leakage gap. The floor of the gutter defines an increased depth portion 72 at the exit end of the gutter 62.

Abstract: A component, such as a blade, vane or combustor wall of a gas turbine engine comprises two walls defining a coolant passage and has an array of pedestals extending between the two walls for heat removal. Each pedestal changes in cross-section along its length. Alternate rows of pedestals are arranged such that their larger cross-sectional area is adjacent one wall then the other. When a coolant flows through the passage it is forced to flow between one wall and the other wall so as to increase turbulence and hence mixing for a more even coolant temperature. The array of pedestals can also be used to tailor the individual heat loads on each wall independently and has the ability to use differing levels of blockage to counter adverse pressure gradients along successive rows of pedestals.

Abstract: A separator device is provided for separating dirt particles from a flow of cooling air fed to airfoils of the turbine section of a gas turbine engine. In use the separator device extends across a conduit which bypasses the combustor of the engine to convey pressurised cooling air carrying dirt particles from the compressor section of the engine to openings which direct the air into the airfoils. The separator device is configured to direct a first portion of the impinging cooling air flow away from the openings and to allow a second portion of the impinging cooling air to continue to the openings. The first portion of cooling air has a higher concentration of the coarsest dirt particles carried by the cooling air than the second portion of cooling air.

Abstract: An aerofoil 20 for a gas turbine engine includes a root portion 22, a tip portion 24 located radially outwardly of the root portion 22, leading and trailing edges 26, 28 extending between the root portion 22 and the tip portion 24 and an internal cooling passage 34. The aerofoil 20 includes a plurality of cooling fluid discharge apertures 36 extending between the root portion 22 and the tip portion 24 in a trailing edge region 28a to discharge cooling fluid from the internal cooling passage 34 to an outer surface 31 of the aerofoil in the trailing edge region 28a and thereby provide a cooling film in the trailing edge region 28a. The cooling fluid discharge apertures 36 are arranged so that the flow rate of the cooling fluid discharged from the internal cooling passage 34 to the outer surface trailing edge region 28a varies between the root portion 22 and the tip portion 24.

Abstract: Providing cooling within hollow blades such as high pressure turbine blades in a gas turbine engine is important to maintain these components within operational margins for the materials from which they are formed. Traditionally, coolant flows in hollow passages have been used along with impingement apertures towards a leading passage for cooling effectiveness. It is known that opposed undulations or ribs can create rotational vortices within the passage. By shaping shaped portions between the opposed undulations and possibly providing undulations upon these shaped portions themselves it is possible to generate stronger more powerful vortices within the passage. These vortices are coupled with the impingement orifices to create proportionally greater impingement jet flow and pressure and therefore cooling effectiveness within the leading passage.

Abstract: Cooling of turbine blades within a gas turbine engine is important. Coolant flows are taken from the engine to provide cooling effects but diminish the efficiency of the engine. Blades rotate and therefore centrifugal effects stimulate flow and pressure to maintain coolant flow presentation upon the blade. More cooling effectiveness is required towards the root of a blade in comparison with the tip. By providing cavities which incorporate return apertures coolant flow can be recycled. The cavities incorporate return portions on one side of a feed passage and a constriction is provided in passage. Thus, a proportion of coolant within the cavities is returned to the passage with pressure maintained by the rotational and centrifugal effects upon the coolant flow through the feed passage. Coolant flow is presented through outlet apertures as a film upon a surface of a blade.

Abstract: Cooling with regard to high-pressure turbine platforms is important in order to maintain gas turbine engine efficiency. Cottage Roof dampers located below junction gaps between adjacent platforms have been used but tend to present spent coolant flow at a high angle relative to hot gas flows about the aerofoil blades. The present arrangement has the junction gap angled such that the emergent coolant flow remains adjacent to the suction side to create a coolant film lingering above that suction side of the platform.

Abstract: A cooled aerofoil for a gas turbine engine has an aerofoil section with pressure and suction surfaces extending between inboard and outboard ends thereof. The aerofoil section includes first and second internal passages for carrying cooling air. The aerofoil section further includes a plurality of holes in the external surface of the aerofoil section which receive cooling air from the internal passages. The external holes are arranged such that cooling air exiting a first portion of the external holes participates in a cooling film extending from the leading edge of the aerofoil section over said pressure surface and cooling air exiting from a second portion of the external holes participates in a cooling film extending from the leading edge over said suction surface. The first portion of external holes receives cooling air from the first internal passage, and the second portion of external holes receives cooling air from the second internal passage.

Abstract: A gas turbine engine rotor blade has an airfoil portion containing one or more internal conduits. Each conduit extends to an end of the airfoil portion. The blade has a shroud at the end of the airfoil portion for sealing the blade to a facing stationary engine portion. There is a fillet portion which joins the end to the shroud. The fillet portion eases the transition from the outer surface of the airfoil portion to the outer surface of the shroud and has a cavity which extends from each conduit and expands laterally relative thereto. The area of the cavity on a cross-section through the fillet portion perpendicular to the radial direction of the engine and at an expanding part of the cavity is greater than the area of the conduit, or the combined areas of the conduits, on a parallel cross-section at the end of the airfoil portion.

Abstract: Within aerofoils (50, 150, 250, 350), and in particular nozzle guide vane aerofoils in gas turbine engines problems can occur with regard to coolant flows (56, 57; 156, 157; 256, 257; 356, 357) from respective inlets at opposite ends of a cavity (60, 160, 260, 360) within the aerofoil (50, 150, 250, 350). The cavity (60, 160, 260, 360) generally defines a hollow core and unless care is taken coolant flow can pass directly across the internal cavity. Previously baffle plates were inserted within the cavity to prevent such direct jetting across the cavity. Such baffle plates are subject to additional costs as well as potential unreliability problems. Baffles (55, 155, 255, 355) formed integrally with a wall (54, 154, 254, 35) within the aerofoil (50, 150, 250, 350) allow more reliability with regard to positioning as well as consistency of performance. The baffles (55, 155, 255, 355) can be perpendicular, upward or downwardly orientated or have a compound angle.

Abstract: Within aerofoils, and in particular nozzle guide vane aerofoils in gas turbine engines problems can occur with regard to coolant flows from respective inlets at opposite ends of a cavity within the aerofoil. The cavity generally defines a hollow core and unless care is taken coolant flow can pass directly across the internal cavity. Previously baffle plates were inserted within the cavity to prevent such direct jetting across the cavity. Such baffle plates are subject to additional costs as well as potential unreliability problems. Baffles formed integrally with a wall within the aerofoil allow more reliability with regard to positioning as well as consistency of performance. The baffles can be perpendicular, upward or downwardly orientated or have a compound angle.

Abstract: Within components such as high pressure turbine blades and aerofoils in a gas turbine engine it is important to provide cooling such that these components remain within acceptable operational parameters. Typically, film cooling as well as convective cooling is utilised. Film cooling requires holes from a feed passage from which the coolant is presented upon an external surface to develop the film. The holes themselves can create cooling through convective cooling effects. In order to maximise the convective cooling effect holes are created which have an indirect path about a direct line between an inlet and an outlet for the hole. By creating an indirect path in the form of a helix or spiral which in turn may have a variable cross sectional area from the inlet to the outlet control of coolant flow can be achieved.

Abstract: Cooling arrangements have been provided for blades and in particular turbine blades utilising gas turbine engines. Generally for internal strength a leading passage has been separate by a solid wall from a feed passage as impingement apertures may diminish structural strength as centres for stress concentration. However, impingement apertures allow impingement jets which have improved cooling efficiency. By providing a leading passage which is divided at least into a lower section and an upper section the lower section can have a wall which is solid for structural integrity whilst an upper section has impingement apertures for greater cooling efficiency.

Abstract: With regard to cooling turbine blades in a gas turbine engine a compromise has to be made between convective cooling within the inner cavity defining a flow path for coolant and the blow rates for developing film cooling on an outer surface of the aerofoil. By providing a chamber between the flow cavity and external apertures reconciliation between the necessary flow rates for convective cooling within the cavity defining the pathway for coolant flow within the aerofoil and the necessary coolant blowing rate for film development can be achieved.

Abstract: An aerofoil for a gas turbine engine, the aerofoil comprises a leading edge and a trailing edge, pressure and suction surfaces and defines therebetween an internal passage for the flow of cooling fluid therethrough. A particle deflector means is disposed within the passage to deflect particles within a cooling fluid flow away from a region of the aerofoil susceptible to particle buildup and subsequent blockage, such as a cooling passage for a shroud of a blade.