Snecma S.A. is a French multinational aircraft and rocket engine manufacturer headquartered in Courcouronnes, France. Alone or in partnership, Snecma designs, develops, produces and markets engines for civil and military aircraft, launch vehicles and satellites. The company also offers a complete range of engine support services to airlines, armed forces and other operators. Snecma is a subsidiary of Safran. Wikipedia.
Snecma | Date: 2016-06-15
A propulsion assembly for an aircraft, the assembly including a turbojet having at least one unducted propulsive propeller, and an attachment pylon for attaching the turbojet to a structural element of the aircraft, the pylon being positioned on the turbojet upstream from the propeller and having a streamlined profile defined by two opposite side faces extending transversely between a leading edge and a trailing edge. The pylon includes a plurality of blow nozzles situated in the vicinity of its trailing edge and configured to blow air taken from a pressurized portion of the turbojet, the blow nozzles being positioned over at least a fraction of the trailing edge of the pylon that extends longitudinally facing at least a portion of the propeller. A method of reducing the noise generated by a pylon attaching a turbojet to an aircraft is presented.
Snecma | Date: 2016-11-25
A fiber structure made as a single piece by multilayer weaving using a method including weaving warp yarns of at least a first set of layers of warp yarns with weft yarns including at least some that are woven with extra length so as to have warp yarn end portions available that extend beyond the zone of weaving, the warp yarn end portions being returned to be woven with warp yarns by being reinserted in layers of warp yarns, and a hollow, or tubular, portion being formed by looping the first woven set of layers of warp yarns back onto itself and applying traction to the ends of the reinserted weft yarns so that a fiber preform for a part including a hollow portion can be obtained as a single piece.
Snecma and French National Center for Space Studies | Date: 2016-11-10
A feed system for feeding a rocket engine with a liquid propellant includes a feed circuit, and a device to vary a volume of gas in the feed circuit. The device is configured to cause a volume of gas in the feed circuit to vary while the rocket engine is in operation. The device to vary gas volume includes at least one variable-flow-rate gas injector to inject gas into the liquid propellant in the feed circuit. Methods of suppressing a POGO effect are also provided.
Snecma | Date: 2016-04-28
A preform for a turbine engine blade, comprising a main fiber preform obtained by three-dimensional weaving and comprising: a first longitudinal segment, suitable for forming a blade root; a second longitudinal segment, extending upwards from the first longitudinal segment and suitable for forming an airfoil portion; and a first transverse segment, extending transversely from the junction between the first and second longitudinal segments to a substantially linear distal edge and suitable for forming a first platform; the preform further including at least one attachment tab provided under the first transverse segment at its distal edge, suitable for forming an attachment portion of the platform.
Snecma | Date: 2017-01-25
A device for searching for defects on parts that are masked, such as turbine engine blades, the device including a tubular sheath, a light-guide guiding light, an image-transmission mechanism transmitting images housed inside the sheath, an examination head at a distal end of the sheath including an illumination mechanism and an image-taking mechanism connected to the light-guide and to the image-transmission mechanism housed in the sheath, a mechanism spraying a succession of penetrant test materials on the part for inspection including a capillary slidably guided in a duct housed in the sheath, and a mechanism adjusting orientation of the examination head at the distal end of the sheath.
Snecma | Date: 2016-12-27
A device for mounting a spark plug in a combustion chamber of a gas turbine engine includes a chimney including a collar extending radially inwards, a washer fastened on an axial end of the chimney so as to project towards the inside of the chimney, and a bushing forming a spark plug guide and including an inner collar and an outer collar that are axially spaced apart from each other by a cylindrical portion. Each collar extends radially outwards. The bushing is floatingly mounted inside the chimney with its collars axially positioned between the collar of the chimney and the washer. The inner collar comes in operation to bear against the collar of the chimney. The outer collar presents an outside diameter (d1) greater than the inside diameter (d2) of the washer.
Snecma | Date: 2014-12-08
A blade for a turbomachine bladed wheel, the blade comprising a root, an airfoil, and a tip. The root and the tip have respective platforms, each presenting a surface (15) on a side toward the airfoil, which surfaces are referred to respectively as the root platform wall and the tip platform wall. Each of these platform walls is constituted by a pressure side portion and a suction side portion situated respectively pressure side and on the suction side and meeting at a crest curve (45, 65). Fabrication of the blade is facilitated in particular by the fact that every point of a first surface selected from the pressure side and the suction side and every point of the root and tip platform wall portions situated on the same side as the first surface presents a normal forming an acute angle or a right angle relative to a direction referred to as the first fabrication direction. A method of modeling the blade.
Snecma | Date: 2017-01-04
The invention concerns a brush seal system, for application as an air/oil seal in a turbomachine shaft bearing, having an axis of rotation, the seal comprising a layer of carbon bristles (23), held between a first ring, referred to as the front ring (40), disposed upstream of a flow of air passing through the seal, and a second ring, referred to as the rear ring (60), disposed downstream of said flow of air, the surface of the layer of bristles, which is turned towards the front ring (40), being provided with a non-metal flexible element (70) that stops a portion of said flow of air (100) that flows through the seal in a direction substantially parallel to said axis of rotation.
Snecma | Date: 2017-02-15
The invention relates to a method for the treatment of an alloy based on titanium aluminide. The method comprises the following steps during which no hot isostatic pressing is carried out: a semi-finished product (7) produced by centrifugal casting is obtained; and said semi-finished product is then heat-treated in order to obtain a microstructure of the alloy comprising gamma grains and/or lamellar grains (alpha2/gamma).
Snecma and Safran | Date: 2017-04-19
The invention relates to a method for producing a low-alloy steel ingot, comprising the following steps: a) melting all or part of an electrode using a vacuum arc remelting process, the electrode comprising, before melting, iron and carbon, the melted portion of the electrode being collected in a crucible and thus forming a melt within the crucible, and b) solidifying the melt by means of a heat exchange between the melt and a coolant, the heat exchange carried out enabling an average solidification speed to be established during step b), which is no higher than 45 m/s, and enabling a low-alloy steel ingot to be obtained.