Societe Nationale D'etude Et De Construction De Moteurs D'aviation

Snecma

Snecma Moteurs

Alain M Lardellier

Robert Kervistin

Georges Mazeaud

Claude C Hallinger

Alexandre Forestier

Francois E Crozet

Raymond P Thetiot

An air circulation method in a turbomachine compressor includes minimizing an inner flowpath between two adjacent blades by providing labyrinths on an inner casing between the two adjacent blades, and sucking in air from the minimized inner flowpath through a radially inner orifice of a vane faced by the labyrinths. The method further includes directing the sucked in air through the vane, bleeding the air from the vane through a radially outer opening of the vane and through an orifice of an outer casing. The air is collected from the vane into a manifold outside the compression stage. A compressor arrangement for circulating air includes a suction device for sucking in air present in the inner flowpath between labyrinths and the vane, and for sending the air into the vane of the stator. The arrangement also includes a device for bleeding air in the vane of the stator and for sending the air outside the compressor.

Method for air circulation in a turbomachine compressor, compressor arrangement using this method, compression stage and compressor incorporating such a arrangement, and aircraft engine equipped with such a compressor

A turbojet includes a differential gear with a first planetary pinion driven by the shaft of the high pressure spool and a second planetary pinion driven by the shaft of the low pressure spool. The planetary pinions drive satellite pinions mounted in a cage by which the ancillary machines are driven. The satellite pinions and said cage are co-rotary and the mechanical transmission ratio Rbetween the high pressure shaft and the first planetary pinion of the differential gear and the transmission ratio Rbetween the low pressure shaft and the second planetary pinion of the differential gear are such that the power extraction distribution between the high pressure spool and the low pressure spool at idle speed is between 80%/20% and 20%/80%. The operation of the high pressure compressor is not affected by the maximum power drawn by the ancillary machines.

Twin-spool turbojet with means for driving ancillary machines

A turbine wheel for a turbomachine, the disk of which comprises upstream and downstream ribs extending in the annular direction around an axis, each blade segment installed on the disk being retained by the disk in an external radial direction using upstream engagement part forming part of the segment root and cooperating with complementary upstream engagement part forming an external radial end of the upstream rib, and downstream engagement part forming part of the root and capable of cooperating with complementary downstream engagement part forming an external radial end of the downstream rib. Furthermore, the upstream and downstream ribs are movable from a separated engagement position to a close position, and vice versa, so that each blade segment can be assembled on the turbine disk.

Turbine wheel for turbomachine and the assembly method for such a wheel

A high bypass ratio turbojet engine comprising a fan rotated by the shaft of a low pressure turbine via a speed reducer is provided with a thrust reverser device by providing the speed reducer with first and second epicyclic gear trains which are mounted in parallel between the low pressure turbine and the fan and which are arranged in such a way as to drive the fan in a first direction of rotation when the engine is operated in a direct thrust mode, and to drive the fan in the opposite direction of rotation when the engine is to be operated in the reverse thrust mode.

Method and device for reversing the thrust of very high bypass ratio

A hollow blade for a turbomachine includes a unitary body having a multiplicity of transverse cavities in at least the aerofoil shaped portion of the blade, and plugs disposed within the cavities for restoring the surface continuity of the intrados and extrados faces of the aerofoil shaped portion, the plugs being rigidly secured to the unitary body, such as by welding.

Hollow blade for a turbomachine

A hollow blade for a turbomachine comprises a unitary body having a multiplicity of transverse cavities in at least the airfoil shaped portion of the blade, and plugs disposed within the cavities and restoring the surface continuity of the intrados and extrados faces of the aerofoil shaped portion, the plugs being rigidly secured to the unitary body, such as by welding.

Hollow blade for a turbomachine and method of manufacturing said blade

A turbojet propulsion engine for supersonic aircraft has a primary unit including a compressor, a combustion chamber, a turbine which drives the compressor, and an exhaust assembly, and a secondary unit including a compression fan assembly arranged in an annular secondary duct surrounding the primary unit, the fan assembly having at least one stage of rotor blades rigidly connected to the shaft which drives the compressor of the primary unit and is disposed between an upstream stage of fixed inlet guide vanes and a downstream stage of fixed flow straightener vanes, the inlet guide vane stage and the flow straightener vane stage each being associated with an adjuster for adjusting the pitch of the respective vanes.

Variable cycle propulsion engine for supersonic aircraft

A thrust reverser for a turbofan engine having a very high bypass ratio is disclosed having a plurality of baffles pivotally attached to a gas turbine engine housing so as to extend into a cold flow air stream emanating from the turbofan exit. The baffles are pivotally attached to the gas turbine engine housing and may be moved into extended, thrust reversing positions in which some of the baffles form a greater angle with the gas turbine engine housing than the remainder of the baffles. By moving the baffles located generally on opposite upper and lower portions of the gas turbine engine housing to the greater angles, the requisite thrust reversing force may be developed while at the same time minimizing the overall vertical dimension of the engine housing so as to provide the maximum amount of ground clearance for the turbofan engine. Secondary baffles are provided between the main baffles to close open spaces between the main baffles. Due to the orientation of the baffles in their extended, thrust reversing positions, the transverse configuration of the baffles is generally oval.

Thrust reverser for a high-bypass ratio turbofan engine

A combined turborocket and ramjet propulsion unit comprises an air intake duct, and an air compressor with two counter-rotating rotor stages disposed downstream of the duct in an annular path formed between an outer casing and a central body which is maintained in position relative to the casing by structural arms. The rotor stages of the compressor are driven by a power turbine driven by combustion gases from a gas generator which burns liquid propellants. The power turbine includes two interleaved counter-rotating modules arraanged within the central body in a position longitudinally between the two compressor stages which they drive, and the gas generator is disposed axially within the central body to the rear of the turbine modules, the generator supplying the combustion gases to the turbine in an upstream direction through a central ejection chamber and an annular reversing chamber which redirects the gases rearwards through the turbine. The gases from the turbine are discharged into the compressed air stream at the rear of the central body and are subjected to afterburning before discharge through an exhaust nozzle. On changeover to ramjet operation the fuel supply to the gas generator is shut off and is directed instead to fuel injectors disposed in a combustion chamber located in the air flow path downstream of the compressor. The compressor blades are feathered and the fuel is burned in the combustion chamber with the air compressed in the air intake duct.

Combined turborocket and ramjet propulsion unit

A gas turbine engine with counterrotating fans placed upstream from the engine so that gas circulates from upstream to downstream at the level of a LP compressor (1), then from downstream to upstream in a HP compressor (5), chamber an (6) and HP and LP turbines (7 and 8), then again downstream in first and second turbines (10, 11) before being expelled into the cold airflow coming from first and second fans (14, 15).

Counterrotating fan engine

A gas turbine engine intended for use as an aircraft engine which includes a gas generator which supplies interdigitated, contra-rotating radially inner and outer low-speed power turbines driving forward mounted contra-rotating front and rear fans, the gases flowing through the gas generator from the rear of the engine towards the front, and then flowing in a rearward direction through the power turbines. The front fan is driven by the radially inner power turbine via a central shaft extending towards the front of the engine and supporting a disc carrying the front fan, and the rear fan is driven by the radially outer power turbine via a forwardly extending drum which is rotatably mounted between the central shaft and a stationary structure of the engine and which carries the rear fan. This structure permits the pod mounting of a high by-pass ratio engine under wing of an aircraft.

Contra-rotating fan engine

A turbojet bypass engine includes an upstream fan of a conventional type also a downstream fan arranged to rotate in the opposite direction to the upstream fan and driven by a free turbine interleaved with the low pressure turbine which drives the upstream fan. The two fans are supplied by separpate overlapping and inverleaved air flow paths which are formed largely within the nacelle structure of the engine, giving the nacelle an ovoide shape which allows such engines with a high bypass ratio to be mounted below the wings of an aircraft.

High by-pass ratio turbojet engine with counterrotating upstream and

An exhaust nozzle assembly for vectoring the thrust of the exhaust gases from a turbojet engine is disclosed wherein the exhaust gases are vectored by an assembly that is separate from the flaps that are utilized to adjust the cross-sectional area of the exhaust nozzle. The thrust vectoring exhaust nozzle assembly has a moveable thrust vectoring assembly comprised of inner and outer vectoring members, each of which have a generally annular configuration. The vectoring members are pivotally attached to the exhaust nozzle so as to pivot about an axis extending generally perpendicularly to the longitudinal axis of the exhaust duct.

Thrust vectoring nozzle assembly

A nacelle for mounting under the wing of an aircraft a turbojet engine unit of the rear contrafan type with a very high by-pass ratio, the engine including a gas generator driving two overlapping contra-rotating turbines integral with ducted contra-rotating propellers downstream of the gas generator. The nacelle includes generally cylindrical inner and outer cowlings defining the secondary flow path containing the propellers, and a mast for suspending the engine unit comprising a pair of arms disposed in the longitudinal vetical axial plane of the engine unit and contained in a fairing, and a horizontal carrier beam fixed to the lower ends of the arms and disposed between the inner cowling and the engine casing. The upper ends of the arms are fixed to a box structure of the wing either directly or through a conventional engine pod suspension mast. In the former case the thickness of the outer cowling is integrated into the thickness of the wing, and the outer side of the cowling merges with the lower wing surface by means of a Karman type profile evolving in a direction from upstream to downstream in such a manner that, in an axial longitudinal plane vertically through the longitudinal axis of the engine unit, the generatrix defining the inner side of the outer cowling is overall tangential to the lower wing surface. The inner and outer cowlings are each divided into 120.degree. sectors, the lower two of which can be pivoted outwards and upwards to simplify maintenance.

Wing mounting nacelle for a very high by-pass ratio turbojet aero-engine

A housing for an axial compressor is disclosed having an inner and outer wall surrounding the compressor rotor, the walls being joined by a number of flexible connecting rods, connecting lugs and a connecting block. An outer surface of the inner wall has circumferentially extending corrugation and the rods are attached thereto at peaks in the corrugation. The flexible connecting rods are located in alignment with a leading edge and a trailing edge of stator vanes which extend from an inner surface of the inner wall. The housing may be cast as an integral, one piece element and subsequently subdivided into arcuate segments to facilitate attachment to the compressor.

Growing community of inventors

Melun, France

Alain M Lardellier