Abstract: The present invention relates to cooled gas turbine engine aerofoils particularly for turbine stator vanes or tubine rotor blades. The leading edge region of a hollow aerofoil is provided with rows of cooling air passages, which are arranged, in operation, to direct cooling air in the opposite direction to the local flow of the hot gas stream. The cooling air passages are substantially parallel, and have relatively large diameters to reduce the possibility of blockage of the cooling air passages by sand. An air guide tube in the hollow aerofoil is provided with large apertures at its leading edge to minimize the area for sand to adhere to.

Abstract: In an axial flow turbo-machine such as a gas turbine engine, a foil cap for hollow blades or cantilevered vanes, aft of the combustion chamber thereof is provided, the cap having cooling apertures therethrough which diverge from inside to outside thereof, the improvement being, placing at least some of such cooling apertures to intersect with the junction of end and side surfaces of such cap, to scallop same, so that such cooling apertures cannot be blocked by contact of such cap with a clearance control body in such engine. The so-positioned junction-intersecting, cooling apertures, intersect the foil cap surfaces at an angle and lay down a cooling air film on the end and side surfaces of such cap, even when the cap is contacted with the clearance control body, to maintain a cooling film shield thereon against high temperature engine combustion gases and to reduce the oxidation and erosion of such foil cap that would otherwise occur.

Abstract: A turbine blade squealer tip has a plurality of holes defined through the end cap of the blade tip portion and located contiguous with an interior surface of the squealer tip wall along at least one of the turbine blade pressure and suction sides of the tip cap for providing effective cooling air on the squealer tip wall. Each tip hole has an inner portion which communicates with the interior of the blade and an outer portion which communicates with a cavity defined by the blade end cap and the peripheral wall of the squealer tip. The cross-section of the inner hole portion is circular and the inner hole portion overall defines a right cylinder. The cross-section of the outer hole portion is rectangular and the outer hole portion overall defines a rectangular trapezoid.

Abstract: Cooling passages are accurately formed along the faying surfaces of a pair of diffusion bonded members such as a pair of half sections used to fabricate an airfoil. A particularly advantageous application of the invention is the photoetching of cooling air grooves into the opposed surfaces of a diffusion bonding foil used to form a diffusion bond between the faying surfaces of a trailing edge portion of a turbine blade or turbine vane. Such grooves may be made extremely small and in high numbers to promote efficient cooling of the trailing edge portions of these airfoils.

Abstract: A rotor blade such as a turbine rotor blade for a jet engine. The airfoil blade portion of the rotor blade has a plurality of longitudinally extending coolant passageways preferably interconnected to define a serpentine coolant circuit. Passageways channeling coolant from the blade root to the blade tip are positioned in a first row proximate the pressure side of the airfoil blade while passageways channeling coolant from the blade tip to the blade root are positioned in a second row adjacent the first row and proximate the suction side of the airfoil blade to take advantage of the Coriolis force acting on the coolant in the passageways of the rotating blade to improve overall heat transfer effectiveness.

Abstract: A rotor blade such as a turbine rotor blade for a jet engine. The airfoil blade portion of the rotor blade has a plurality of longitudinally extending coolant passageways preferably interconnected to define a serpentine coolant circuit. Each passageway has a wedge shape including a base and an opposing tapered tip. For passageways channeling coolant from the blade root to the blade tip, the bases are positioned proximate the pressure side of the airfoil blade and the tapered tip is positioned proximate the suction side of the airfoil blade to take advantage of the Coriolis force acting on the coolant in the passageway of the rotating blade to improve overall heat transfer effectiveness.

Abstract: A cooled wall structure including a hot side, a cold side, a linear slot opening through the hot side, a plurality of diffusion chambers below the hot side separated therefrom by relatively thin bridge sections of the wall structure and arrayed in checkerboard fashion on opposite sides of the linear slot and opening into the linear slot through the sidewalls thereof, and a plurality of passages from the cold side to each of the diffusion chambers. The cold side is exposed to coolant gas under pressure and the passages are aimed at the bridge sections so that jet of cooling gas issuing from the passages impinge against the bridge section for convection cooling the hot side. The bridge sections prevent direct penetration of the coolant gas jets into the environment adjacent the hot side. The coolant gas flows from the diffusion chambers into the linear slots and from the linear slots over the hot side to form on the latter a coolant film or blanket.

Abstract: An apparatus and method for varying the cooling air flow within a gas turbine bucket tip. Each turbomachinery blade contains at least one radial cooling passage located between a hollow interior and an outside of the blade. A transversely-oriented elongate channel connects at least one of the cooling passages with the trailing edge of the blade. Secured within the transversely-oriented channel is a pin which extends into at least one of the radial cooling passages to partially obstruct the cooling fluid flow depending on the needs of the design.

Abstract: An airfoil includes a plurality of interior cooling air paths arranged so as to provide crossover metering and pressure side bleed of cooling air at the trailing edge region of the airfoil.

Abstract: A variety of configurations for convergent-divergent film cooling holes are disclosed, together with the hole drilling methods necessary to achieve the configurations.

Abstract: A two part vane (38) comprises a metallic downstream portion (42) and a high temperature leading edge insert (40) disposed between two retaining buttons (46,48) loosely fit into recesses (50) formed in the inner platform (52) and the outer platform. The separation between the leading edge insert (40) and the downstream portion (42) creates two cooling louvers (64,66) for conducting cooling air from an internal cavity (58) through the cooling louvers (64,66) and down the surfaces (54,56) of the downstream portion (42).

Abstract: A vane for a turbojet engine, is disclosed having an airfoil-shaped body with a leading edge, a trailing edge, a generally concave sidewall and a generally convex sidewall defining a hollow vane interior. A cooling air supply duct extends substantially over the entire length of the vane and communicates with a turbulence chamber in the vicinity of the leading edge which is separated from the supply duct by a partition having air cooling orifices to allow the air to pass from the cooling air supply duct into the turbulence chamber. The air from the turbulence chamber is evacuated through evacuation orifices defined by the generally convex sidewall in the vicinity of the leading edge. A plurality of heat exchange members are located in the interior of the vane such that they are spaced apart, extend substantially parallel to each other and substantially perpendicular to a longitudinal axis of the vane.

Abstract: A gas turbine engine turbine aerofoil blade includes an aerofoil portion having pressure and suction flanks. The flanks are internally interconnected by wall member which cooperates with the flanks to define first and second cooling passage portions which are interconnected by a bend portion. The wall member is locally thickened adjacent the bend portion. In the second cooling passage portion the locally thickened wall member portion progressively increases in thickness towards at least one of the flanks so as to eliminate any acute angle between the flanks and the thickened wall member portion adjacent thereto.

Abstract: An aerofoil for a gas turbine engine turbine rotor blade or stator vane is subject to film cooling by multiple rows of small cooling air exit apertures in the exterior surface of the blade or vane. Each exit aperture is supplied with cooling air through at least two holes extending from the aperture through the wall of the blade or vane to interior chambers or passages. The holes are mutually intersecting and their intersection forms the exit apertures and defines a flow constriction for controlling the flow rate of cooling air through the holes and out of the aperture. If the holes' centerlines intersect behind the plane of the exterior surface by an optional distance, the flow constriction is spaced apart from the exit aperture and is within the wall thickness, the exit aperture being enlarged. These film cooling hole configurations reduce the liability of the holes to block up due to contamination by environmental debris.

Abstract: Augmenting ribs (40) of zig-zag configuration are provided on a heat transfer surface (38) for increasing local heat transfer in a selected zone (68,70) of the surface (38).

Abstract: A gas turbine engine is provided with hollow guide vanes having thermally responsive actuators mounted within each for individually controlling the cooling air flow therethrough in response to local temperature variations.

Abstract: A variety of configurations for convergent-divergent film cooling holes are disclosed, together with the hole drilling methods necessary to achieve the configurations.

Abstract: A blade of a gas turbine includes a main body having a dovetail portion and a blade portion extending from the dovetail portion. A cooling air passage for flowing a cooling air is formed in the main body to cool the blade portion. The passage includes a cooling air inlet port open to the dovetail portion and an outlet port open to an extended tip of the blade portion. A first passage portion extends from the inlet port to the portion close to the extended tip along a leading edge of the blade portion. A final passage portion extends from the dovetail portion to the outlet port. The flow sectional area of the final passage portion is gradually decreased from the dovetail portion toward the outlet port. The final passage portion communicates with a number of film cooling holes which are open to the suction side surface of the blade portion.

Abstract: An apparatus and method are provided for preventing the plugging of cooling air distribution holes in a hollow gas turbine vane by particles entrained in the cooling air. The portion of the cooling air is bled from the vane and discharged into the hot gas downstream of the vane, the shunted bleed air carrying the entrained particles.

Abstract: A gas turbine vane has a vane airfoil defining a cavity extending along the longitudinal direction of the vane airfoil. A guide cylinder is disposed in the cavity to guide coolant fluid supplied from an external source thereof. A plurality of flowing holes are concentrated substantially centrally with respect to the vane airfoil in the longitudinal direction.

Abstract: In order to facilitate efficient use of high pressure cooling air in a turbine rotor blade its aerofoil has a triple-pass convoluted cooling air duct in its leading edge region, and a triple-pass convoluted cooling air duct in its mid-chord region, both of them being fed from a common high pressure inlet in the root of the blade. The trailing edge region has a single-pass duct fed by low pressure cooling air from an inlet located just under the blade platform. The shroud of the blade also has cooling air passages and these are fed from the ends of respective ones of the ducts. Air from the ducts also exits through rows of film cooling holes to film cool the concave flank of the aerofoil and through a row of holes in its trailing edge to remove heat from the thinner metal section in that area.

Abstract: The invention comprises a wall having first and second spaced surfaces, and a first plane disposed therebetween which includes first and second coplanar and orthogonal axes. A passage extends between the first and second surfaces and includes a portion having longitudinal axis disposed at an acute angle to the first plane, the first section being disposed perpendicularly to the longitudinal axis and the second section being disposed parallel to the first plane. The passage first section is generally elliptical and the passage second section is generally circular.

Abstract: An improved turbine blade tip with diffusion cooling holes in the tip is disclosed. One particular embodiment of the invention provides an improved squealer blade tip with diffusion cooling holes in the tip. Yet another embodiment of the invention provides blade tip diffusion cooling holes comprising a first cylindrical portion coupled to a second conical portion.

Abstract: The airfoil shaped body has a separate leading edge portion (14) spaced from the main body (12). Slots (22) thereby formed discharge cooling air parallel to surface (38) of the main body. A step change across the slot between the leading edge surface (52) and the main body surface (38) facilitates smooth introduction of cooling air.

Abstract: A dirt removal means for air cooled blades for removing dirt at the blade of a gas turbine engine. The means is a stamped out sheet metal that defines a deflector or plurality of deflectors adapted to overlie the inlets of the blade's internal cooling passages for diverting the dirt entrained air through a high velocity air stream and discharging the dirt entrained air while allowing the cleaner portion of air to turn the corner of the deflector and flow through the blades cooling passages. These means can be applied to existing blades.

Abstract: Dirt removal means for an internally air cooled blade for a gas turbine engine of the type that includes multi passes some of which are serpentine as made in situ by casting the ribs so as to be angularly disposed at the root of the blade and a straight through passageway with an opening at the tip. The velocity of the airstream in the straight through passageway being sufficiently high to carry the dirt through the opening and the angularly disposed ribs overlying the entrance to the other passageway so as to divert the dirt entrained airstream into the straight through passageway while allowing relatively dirt-free air to turn the angle of the rib to enter the serpentine passes.

Abstract: Cooling air flows over the inner wall of the blade, and emerges through sl orifices provided in the blade jacket in the region of the boundary layer. The cooling air is admitted tangentially into an eddy tube provided with a closure and with a throttle in the region of the latter. The cooling air flow, which is cooled after flowing through the closure is fed into the blades and, after passing over the inner wall of the blade jacket, escapes from each blade in the region of the boundary layer. The heated air flow which escapes from the throttle is evacuated from the blade region. This airflow can be mixed with the cooling air or be introduced into the main gas flow.

Abstract: A method and apparatus for optimizing the radial clearance of rotor and stator vanes with their opposed structure for axial flow compressors of gas turbine power plants in which rotor disks are vented and thermally controlled by compressed air taken from the main flow path in the compressor via openings in the inner surface of the main flow path at one or more of the compressor stages. The removed air is supplied to annular spaces formed between rotor and/or seal support disks.

Abstract: The penetrating members (21, 35, 37, 38, 39) are disposed inside the cooling passage (8) at positions so as to penetrate through the cooling passage (8), and have both of ends thereof fixed to the rear side wall (17) and the body side wall (18). The projecting members (33) (34A, 34B) are disposed inside the cooling passage (8) so as to project from the rear side wall (17) or the body side wall (18). The rectification ribs (36) are disposed at intermediate positions between the penetrating members (21, 35, 37, 38, 39) or the projecting members (33, 34A, 34B). The penetrating members (21, 35, 37, 38, 39) or the projecting members (33, 34A, 34B) disturbs the main stream (3a) of the cooling fluid (3) near the internal partition (19) in both directions of the leading edge wall (16) and the first internal partition (19) and make the main stream (3a ) non-uniformly or causes its channelling.

Abstract: A turbine airfoil, such as a turbine blade or nozzle vane, is disclosed for use in a high temperature environment. The airfoil comprises a center post and at least one side piece. The side piece is attached to the center post so that, at room temperature, a clearance between the center post and the side piece permits limited relative movement between the post and side piece. This clearance space, however, is dimensioned so that at the operating temperature of the turbine, thermal expansion of the center post and/or side piece substantially eliminates the clearance as well as the limited movement between the center post and side piece.

Abstract: A coolable airfoil 10 for rotary machines is disclosed. The airfoil has a passage 54 extending spanwisely through the leading edge region 26 of the blade. The first passage has a plurality of trip strips 66s, 66p canted toward the approaching flow and angled with respect to the wall in the leading edge region to turbulently increase the amount of cooling flowed to the forward most portion of the passage in the leading edge region. In one embodiment, a hole 72 in fluid communication with a turning passage 64 in the tip region of the blade downstream of the first passage is in fluid communication with the trailing edge of the blade.

Abstract: The film of cooling air adjacent the outer surface of the airfoil of a turbine of a gas turbine engine issuing from internally of the turbine subsequent to cooling is controlled by regulating the pressure ratio of the internal to external pressures by forming an internal chamber extending longitudinally in the turbine and having fixed orifices admitting cooling air therein bearing a predetermined relationship to the exit orifices forming the film of cooling air. By regulating this pressure ratio the diameter of the exit holes can be longer than heretofore designs for a given application so that they can be precast rather than drilled and can be arranged to give fuller coverage of films of cooling air on the outer surface of the airfoil.

Abstract: A hollow, cooled airfoil has a pair of nested, coolant channels therein which carry separate coolant flows back and forth across the span of the airfoil in adjacent parallel paths. The coolant in both channels flows from a rearward to forward location within the airfoil allowing the coolant to be ejected from the airfoil near the leading edge through film coolant holes.

Abstract: Air cooling of airfoils in a gas-turbine engine is effected through holes which terminate with a diffuser formation at the airfoil surface. The invention is directed to a two-step procedure whereby a laser beam drills the holes very quickly and cost-effectively and whereby an EDM step is relied upon only to form the diffuser shape. The EDM part of the procedure thus occupies but a fraction of the time previously required, and substantial overall economy is realized by integrating these two steps, which are preferably performed in the order stated but which, if desired, may alternatively be performed by laser driling after EDM formation of the diffuser shape.

Abstract: In a turbomachine having stationary and rotating bladed stages, the blades of the rotating bladed stage are cooled by ducting cooling fluid into an interior cavity formed in each blade. Each rotating blade has a tip portion which is closely adjacent an annular shroud to avoid hot gas products bypassing the blades. The required close clearance between the blade tips and the annular shroud has caused manufacturers to provide a recessed blade tip cap and an open plenum at the blade tip to improve cooling flow. This invention minimizes the height requirements of sidewalls to the open plenum by providing an opening in the blade sidewalls whereby cooling air can be discharged from the interior blade cavity and the blade plenum without regard to the clearance between the blade tip and the annular shroud.

Abstract: A hollow, cooled airfoil has a pair of nested, coolant channels therein which carry separate coolant flows back and forth across the span of the airfoil in adjacent parallel paths. The coolant in both channels flows from a rearward to forward location within the airfoil allowing the coolant to be ejected from the airfoil near the leading edge through film coolant holes.

Abstract: A coolable wall configuration includes a slot formed between two wall portions for carrying coolant fluid in a downstream direction wherein the slot is divided into a plurality of parallel channels by as plurality of parallel barrier walls extending in a direction perpendicular to the downstream direction, the barrier walls having openings therethrough at regular intervals to interconnect the channels, wherein the openings in adjacent barrier walls are staggered so that cooling fluid flowing through each opening impinges upon a wall portion of the next barrier wall and ultimately traverses a square wave-like flow path as it moves downstream from channel to channel. This configuration is particularly suitable for use in the trailing edge region of an airfoil.

Abstract: A cooled highly twisted airfoil (1) includes an integrally formed continuous warped wall (12) defined as a surface of revolution about an axis (13) with the axis determined such that the axis intersects the plane of a section along a desired centerline. Such an internal wall structure separates adjacent cooling cavities (10) and (11) and includes relatively precisely aligned impingement holes (14) for directing cooling air to the leading edge (6) of a highly twisted airfoil. Such a structure minimizes the complexity of the ceramic core and die inserts required to cast such an airfoil, thereby decreasing manufacturing costs while increasing the overall cooling efficiency of the blade.

Abstract: A film cooling passage through the wall of a hollow airfoil for a gas turbine engine has a metering section communicating with the interior of the airfoil for directing a metered amount of coolant through the passage in a first direction, followed by a mixing section to create turbulence in the flow as it leaves the metering section, followed by a diffusing section leading to the passage outlet at the outer surface of the airfoil. The mixing section comprises a sudden jog or step in the flow path of the fluid to suddenly disrupt its forward momentum in the first direction and to create turbulence therein whereby the fluid is more readily able to spread out within the following diffusing section and thereby stay attached to more widely diverging diffusion section walls. Wider diffusion angles in the coolant passage permits the same amount of coolant to be spread out over a wider area of the surface of the airfoil.

Abstract: The wall of a hollow airfoil for a gas turbine engine includes a film cooling slot therein elongated in the longitudinal direction and having a base within the wall and an outlet at the external surface of the airfoil. A plurality of metering passages extend from inlets at the internal surface of the wall and intersect the slot near its base. The metering passages are angled to direct a metered flow of coolant fluid at a sharp angle against a surface of the slot to cause turbulence and diffusion of the coolant fluid within the slot in order that the coolant fluid fill the entire slot. The coolant fluid thereupon exits the slot as a thin film over the surface of the airfoil downstream of the slot outlet along the full length of the slot.

Abstract: A mask particularly useful in the weld repair of air cooled gas turbine blades and vanes contains a mixture of ceramic particles in a liquid carrier. The mask is applied onto the surface of the blade or vane, and into the cooling holes. Following a sintering treatment, an inert, thermally stable, electrically nonconductive ceramic mask is produced, which is easily removed after welding.

Abstract: A jet flap construction for the compressor of an aircraft gas turbine engine provided with a bleed for bleeding air interstage of the compressor and communicating with the hollowed-out struts in the airflow path to the compressor. The hollow struts are each provided with one or more rows of discrete openings extending from the shroud to the hub on the strut to form an aligned series of jets for discharging the pressurized bleed air and forming a jet flap, thereby providing pre-swirl at the compressor inlet.

Abstract: A gas turbine vane generally comprises an outer hollow vane member provided with a plurality of ribs aligned on the inner wall of the outer vane member and an insertion member of vane shape inserted into the outer hollow vane member so as to rigidly engage with the ribs. A turbulence chamber is defined between the leading edge portions of the outer and inner vane members, and the inner hollow insertion member is provided with numerous orifices at its leading edge portion for injecting cooling fluid into this turbulence chamber. A plurality of cooling passages operatively connected to the turbulence chamber are formed between the flank walls of the outer and inner vane members, and a plurality of orifices are further provided through the flank walls of the inner insertion member so as to communicate the interior thereof with the cooling passages.

Abstract: A film cooling passage through the external wall of a hollow airfoil for a gas turbine engine has a metering section in series flow relation with a diffusing section leading to the passage outlet at the external surface of the airfoil over which a hot gas flows during operation. The diffusing section is generally rectangular in cross section perpendicular to the axis of the passage. Upstream and downstream longitudinally extending, spaced apart, facing surfaces of the diffusing section are joined together by a pair of spaced apart side walls which face each other and diverge from each other in the longitudinal direction toward the outlet of the passage. These side walls blend, along their length, with the downstream surface as a smooth curve of large radius. The diameter of the corner curvature of the passage is on the same order of magnitude as the distance between the upstream and downstream surfaces of the diffusing section at the location in question.

Abstract: The blade has an aerofoil body 10 having a leading edge surface 11 which is cooled by air passing through a helical first passage 12 having first portions passing close to said leading edge surface and alternating with second portions passing through a more nearly central part of the blade section remote from said leading edge. A spanwise but straight second passage 15 extends through the blade in a position within the helical passage and closer to the second than the first portions thereof. Heat abstracted from the leading edge by air flow in said first portions is transferred by the flow to the second portions and from there through the blade material to the flow in the straight passage.

Abstract: The external wall of a hollow airfoil for a gas turbine engine has a plurality of longitudinally aligned diffusing coolant passages having their outlets at the outer surface over which a hot gas is intended to flow. The airfoil external wall also includes a longitudinally extending slot formed in the inner surface thereof. Each of the coolant passages intersect such longitudinally extending slot to define metering inlets to each passage for receiving coolant fluid from the slot at a controlled rate. The coolant diffuses as it passes through each passage and exits as a thin film on the external surface of the airfoil. The slot is cast in the inner surface of the wall at the time of forming the airfoil; and the passages are machined into the wall from outside the airfoil. Very small, accurate metering areas for each passage can thereby be formed in single-piece hollow airfoils without access to the interior of the airfoil.

Abstract: In the fabrication of a hollow airfoil having a longitudinally extending slot in the airfoil wall with the slot outlet at the external surface of the airfoil, a metering passage extending from the coolant compartment within the airfoil to the slot for carrying a metered amount of coolant fluid into the slot is formed by machining a passage completely through the wall from the external surface to the internal surface and which intersects the slot. The portion of the passage between the slot and the external surface of the airfoil is blocked, such as with a plug or by welding. With this fabrication method metering passages for directing coolant fluid from inside the airfoil into the slot may be formed without access to the interior of the airfoil. Coolant fluid from the interior flows into the slot through the unblocked portion of the passage and thereupon flows out of the airfoil through the slot as a film of coolant over the surface of the airfoil.

Abstract: The wall of a hollow turbine airfoil has a longitudinally extending coolant outlet slot in its external surface which intersects, along its length, a longitudinally extending cylindrical channel within the wall. Metering passages extend from the inside surface of the airfoil wall to the cylindrical channel and direct a metered amount of coolant into the channel in a manner which results in a swirling motion being imparted to the fluid as the fluid diffuses within the channel. The coolant is thereupon ejected from the channel through the slot in the external surface as a film on the external surface of the airfoil along the length of the slot. The swirling of the fluid within the cylindrical channel helps diffuse the fluid such that the outlet slot becomes completely filled with coolant, whereby a film of coolant is created on the airfoil surface downstream of the slot over the full length of the slot.

Abstract: The wall of a hollow airfoil has a longitudinally extending slot in its external surface which is intersected, at its base, by a plurality of coolant passages in a longitudinally extending row. Each coolant passage has a metering portion at its inner end which communicates with a coolant compartment within the hollow airfoil. Each passage includes a pair of walls downstream of the metering portion which diverge from each other in the longitudinal direction and intersect with the base of the slot to form an outlet for the passage. The diverging walls of adjacent passages substantially meet each other at the base of the slot, wherein coolant fluid from the metering portions of the passages diffuses in the longitudinal direction as it flows toward and into the slot, filling the entire slot and forming a thin, continuous film of coolant downstream of and along the entire length of the slot over the external surface of the airfoil.

Abstract: Film coolant passages through the wall of a hollow airfoil for a gas turbine engine are oriented to direct coolant fluid therefrom at a substantial acute angle to the downstream direction and at a shallow angle to the surface of the airfoil. Each passage includes a metering portion at its inlet end and a four sided diffusing portion at its outlet end. The diffusing portion includes a pair of adjoining surfaces which are both parallel to a central axis of the passage, and another pair of adjoining surfaces which diverge from the central axis, the diverging pair of surfaces being located on the downstream side of the passage. With this configuration the coolant completely fills the diffusing section and exits as a wide film of coolant within the boundary layer downstream of the passage outlet.