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: 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: 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 | Date: 2015-12-22
A device for circulation of air for a turbomachine, the device including an inlet provided to receive incident airflow, air circulation ducts connected to the inlet, a central part including side walls, peripheral walls arranged at a distance from the central part, so as to form the air circulation ducts, each duct being arranged between one of the side walls of the central part and one of the peripheral walls, each peripheral wall including an upstream end portion delimiting with one of the side walls an inlet orifice of one of the ducts and a downstream end portion delimiting with one of the side walls an outlet orifice of one of the ducts, at least one member mobile in translation relative to the peripheral walls, the at least one mobile member being formed in the central part and arranged so that its displacement varies a section of each of the inlet orifices and a section of at least one of the outlet orifices.
Snecma | Date: 2015-04-02
An obtaining step for obtaining a measurement of the monitored parameter as measured by a sensor and corresponding to an operating point of the engine, the operating point being defined by at least one regulation parameter of the engine; an estimation step for estimating a value of the monitored parameter for this operating point on the basis of a regulated value or a filtered setpoint value of the at least one regulation parameter of the engine defining the operating point; a comparison step for comparing an error between the measurement of the monitored parameter and its estimate relative to at least one threshold determined on the basis of an uncertainty on the error evaluated for the operating point; and a notification step for sending a notification in the event of the at least one threshold being crossed.
Snecma | Date: 2017-03-09
The invention relates to the field of aerial propellers, in particular the field of variable-pitch propellers, specifically for unducted fans. More specifically, the invention relates to a pivot (15) for a blade (14) of a propeller (3a, 3b), the pivot including at least a proximal portion (15a) made of metal and suitable for being retained in a radial orifice of a propeller hub, while being capable of turning in said orifice about a longitudinal axis (Z) of the pivot (15), and a distal portion (15b) including a receptacle (20) suitable for retaining a blade root, and at least one arm (17) of organic matrix composite material extending laterally relative to said longitudinal axis (Z) and supporting a flyweight (16).
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.
Snecma | Date: 2015-09-21
A field of vehicles propelled by reaction, and more specifically to a method of suppressing the pogo effect in such a vehicle. A feed system for feeding a reaction engine of the vehicle includes a hydraulic accumulator enabling a selection to be made from among a plurality of predetermined operating levels, each corresponding to a different volume of gas. In the method, if a first reference criterion is not satisfied by the current level, the hydraulic accumulator is ordered to make a transition, preferably to an alternative level selected from among alternative levels for which the first reference criterion is satisfied and for which no hydraulic resonant frequency crosses any current mechanical resonant frequency during the transition.