Abstract: On a propeller, more particularly one for aircraft applications, an efflux slot (6) originating at the propeller blade trailing edge (5) is provided in the transition area between propeller blade (3) and hub (2) for improving the secondary airflow and dimensioned such that precisely the air boundary layer, but not the main flow, is allowed to flow off. Propeller losses are reduced and propeller thrust and efficiency are increased.

Abstract: A fluid flow machine has a main flow path in at least one stage, with a rotor arrangement and a stator arrangement, resulting in an increased rotor-stator constriction ratio QRS, which satisfies the following equation: [0.2+(KT?0.45)0.1]<QRS, with QRS being defined to the following formula: QRS=KR/KS with KT being the total stage constriction, and with QRS and KT being determined as follows: QRS=KR/KS with KR=ARI/ARA and KS=ASI/ASA KT=ARI/ASA with ARI, ARA, ASI and ASA being calculated as follows: ARI=?(R22?R12) ARA=?(R42?R32) ASI=?(R62?R52) ASA=?(R82?R72).

Abstract: A combustion chamber head of a gas turbine has a confinement enclosing a dampening volume (207) and including a combustion chamber-opposite confinement (206) and a combustion chamber-side confinement (210). The combustion chamber-side confinement (210) is provided as perforated wall (210). In the edge area of the combustion chamber-side confinement (210), cooling air can be routed onto the combustion chamber-side confinement (210) via recesses (203) in the confinement (206). This cooling air, which flows along the combustion chamber-side confinement (210), crosses the cooling air flow through the perforated wall (210) in the combustion chamber (101) without mixing with the latter, as both are separated by walls.

Abstract: A method for reducing noise emissions of an aircraft engine (3) having a gas turbine (7), includes providing a hot gas layer underneath at least one noise-emitting area of the aircraft engine.

Abstract: A main flow path of a fluid flow machine includes N adjacent member blade rows firmly arranged relative to each other in both a meridional direction m and a circumferential direction u. A number of the member blade rows, N, is greater than/equal to 2 and (i) designates a running index with values between 1 and N. A trailing edge HK (i) of a blade of the member blade row (i) is spaced from a leading edge VK(i+1) of a blade of the adjacent, downstream member blade row (i+1) by a meridional edge distance D in a meridional plane established by axial direction x and radial direction r. A value of D along a height of the main flow path increases towards the main flow path confinement at least along a part of the area between the main flow path center and the main flow path confinement.

Abstract: With a method for surface strengthening and smoothening of metallic components, in particular of rotors or rotor drums (7) with integral blading for aircraft engines, the components are loaded in a vessel (2) which is filled with strengthening elements (10). A tumbling movement is performed by which the metallic components are strengthened and smoothened by a relative movement between the workpiece surface and the strengthening elements in one process step. The strengthening elements (10) have a circumferential, rounded edge area, or compressive strengthening area (13) for strengthening the surface, and, extending therefrom on both sides, a flatly curved smoothening area (14) for smoothening the surface roughened by strengthening. With low time and apparatus investment, workpieces can be provided that feature high fatigue strength and advantageous aerodynamic properties.

Abstract: For electrolytically etching the surfaces of integrally bladed rotors (blisks) (6) made of nickel-base material for aircraft gas turbines, auxiliary cathodes (10), in addition to the main cathodes (3) provided in the electrolyte (1), are arranged in the area of the blades (9) remote from the electric contact points at the rotor disk (7). The auxiliary cathodes are adaptable in shape, arrangement and size to the blade and disk geometry, so that a uniform current flow from all parts of the rotor connected as anode via the electrolyte to the main and auxiliary cathodes is produced and an intense and uniform etching effect is achieved. This ensures a reliable structural assessment in all rotor areas and in particular also in the area of the integral blading.

Abstract: A titanium sheet to be formed is heated in a sealingly closed tool by the radiation heat from the heating elements integrated into the tool to a forming temperature not exceeding 600° C., and is deformed towards a cold tool contour by the action of a non-oxidizing gaseous pressure medium introduced into the tool and heated to the hot-forming temperature, as well as by underpressure generated on the side of the workpiece facing away from the pressure medium.

Abstract: Tip grinding of BLISK blades is performed in a static state of an incrementally rotatable BLISK, with a rotational axis (9) of a grinding wheel (4), which is traversable along an upper edge of the blade, being aligned diagonally to an orientation of the blade upper edge, and hence, in a direction of maximum resistance moment of the blades. The apparatus for the performance of the method features a locating device (7) for a BLISK which is incrementally rotatable by an auxiliary drive (8) as well as a high-speed shaft (3) driven by a main drive (2) for blade tip grinding of conventional rotor wheels fittable to the high-speed shaft (3). The grinding wheel (4) is traversable in Y-direction and rotatable about a center axis extending in X-direction, such that the blade tips in the static state can be ground in the direction of the maximum resistance moment of the blades.

Abstract: With a two-shaft engine, the accessory drive gearbox (5) for the operation of a generator and other auxiliaries (6) is connected to the high-pressure shaft (1) via a high-pressure shaft gearbox (3), which is coupled to a low-pressure shaft gearbox (8) connecting to the low-pressure shaft (7), via an overrunning clutch (11), a conical-pulley variable transmission (10) settable on the basis of the shaft speed on both sides, and a first switchable clutch (9). Under certain operating conditions with low speed of the high-pressure shaft or in case of engine failure, the power of the low-pressure shaft, with the clutch (9) engaged, is transferred to the high-pressure shaft gearbox and hence to the accessory drive gearbox via the conical-pulley variable transmission, which compensates for shaft speed difference, and the overrunning clutch, in order to reliably further operate the generator and other accessories with low fuel consumption or by windmilling only.

Abstract: The intake cone for a gas-turbine engine is wound in one piece from fiber compound material with fiber layers crossing one another. It is provided with a fiber compound belt, wound in the circumferential direction of the intake cone, in the connecting area with a mounting flange, which is of segmented design and thus features reduced circumferential stiffness, of a metallic retaining ring attached to a fan rotor disk. The intake cone is easily manufacturable with almost constant wall thickness and in high quality, can reliably be subjected to non-destructive testing and, in combination with the mounting flange, which is flexible in the radial direction, ensures safe connection of the two components despite the different thermal and elastic behavior of the respective materials.

Abstract: An abradable labyrinth seal for a fluid-flow machine seals a sealing gap between a stationary carrier (9) provided with an abradable lining (10) of porous material formed by hollow bodies (11) and a rotary component (4) provided with sealing fins (8) oriented towards the abradable lining. In a preferred embodiment, elongated hollow bodies (11) conforming in shape and size are linearly arranged as an ordered cellular structure side by side and one above the other in x, y and z directions and are interfacially or fully interfacially connected to each other with or without open pores (12). The hollow bodies (11) are arranged such that the tips of the sealing fins (8) are approximately centrally oriented to the hollow bodies (11).

Abstract: In the area of the support struts and/or the aerodynamic fairings downstream of the stator vanes, the cross-section of the bypass duct of a turbofan engine is enlarged such that the pressure variations caused by the stagnation effect of the installations and reacting on the fan are reduced, enabling the fan to be operated with more efficiency and stability and finally the losses of the overall system and the fuel consumption to be reduced. The cross-sectional enlargement is accomplished by modifying the course of the wall in a limited area, actually by gradually enlarging the flow cross-section in the bypass duct in the axial and in the circumferential direction, with this enlargement being confined to the area around the leading edge of the support struts and/or the aerodynamic fairings.

Abstract: A scoop for a fairing 1 of a core engine 2 of an aircraft gas turbine allows air to be supplied from a bypass flow in a bypass duct 3 to several cooling-air distributors in a core-engine ventilation compartment 4. The scoop includes a first tubular flow duct 5, whose inlet opening 6 is arranged in the bypass duct 3 and which extends through the fairing 1, as well as a second tubular flow duct 7, which at least partly encompasses the first flow duct 5 and whose inlet opening 8 is rearwardly offset relative to the inlet opening 6 of the first flow duct 5 in the direction of flow.

Abstract: A method for manufacturing an ejector nozzle tube, includes forming an essentially rectangular plate-type blank 1 to have an undulating configuration on two opposite edge areas 2, 3, subsequently bending the blank around an axis 4, which is arranged centrically and parallel to the edge areas 2, 3, with the edge areas 2, 3 being superposed and subsequently joining the edge areas by point connections 6, providing for the formation of ejector nozzles 5 between the point connections.

Abstract: In the repair of a blisk or blisk drum, the damaged airfoils are completely cut off a low-stress nodal line of the respective blade, except for a blade stump (2), and are each replaced by a new blade repair element (3) of a same shape and size which is accurately clamped onto the blade root by a ledge (5) formed onto its mating end, with this ledge (5) also serving for fixation of the processing fixtures and stabilization of the thin airfoil, and is then welded to the blade root and subsequently subjected to a cutting or non-cutting operation for removal of the ledge (5). This highly efficient repair method can similarly also be applied to the new manufacture of blisks.

Abstract: A turboprop propulsion unit includes at least one pusher propeller 5, 6 driven by an aircraft gas-turbine engine, with the aircraft gas-turbine engine being arranged in front of the pusher propeller 5, 6 in a direction of flight. A turbine outlet area 9 is arranged at the front in the direction of flight and a compressor area 14 faces towards the pusher propeller 5, 6.

Abstract: A running-gap control system of an aircraft gas turbine with a core engine including a turbine whose blade rows have a running gap 13 to the turbine casing 12, with the turbine casing 12 being surrounded by a core-engine ventilation compartment 15 enclosed by a fairing 2 of the core engine, with the fairing 2 forming an inner wall of a bypass duct 1. Air from the bypass duct 1 can be introduced via at least one inlet nozzle 5 into a cooling-air distributor 7 by a control system 6, 10, 11 and the air is subsequently returned to the bypass flow 3.

Abstract: With a door seal for a gas turbine engine, a gap (3) existing between an axially symmetrical component (1) and an assembly formed by several segments (2) is sealed by seal doors (11), which are held via retaining holes (10) at retaining bolts (9) on one of the components, the seal doors (11) being pressed against sealing edges (5, 7) of the two components, with the sealing edges (5, 7) being disposed at a certain distance from each other. The retaining bolts and holes are located outside the pressure surface (A) of the seal doors, formed between the two sealing edges, thus preventing cooling air losses via a gap remaining between the retaining bolts and bores.

Abstract: A method for joining components in TiAl with a braze includes heating the braze with a laser.