Abstract: A carbureted flameholder (30) with optial cooling is provided for a bypass turbojet-engine. The flameholder (30) comprises a body (34) which extends radially into the primary flow. The body (34) is formed by a V-dihedral having two outer plates (35, 36) which intersect at a common ridge apex (37). An air tube (38) is mounted between the two outer plates (35, 36) and at least one fuel conduit (44, 45) is disposed to the rear of the air tube (38). The overall cross-section of the air tube (38) is approximately triangular and the air tube (38) includes a transverse downstream wall that is curved to define a trough (42) in which the fuel conduit (44, 45) is located. The air tube (38) includes orifices (41, 46) directed against the dihedral plates (35, 36) and the fuel conduit (44, 45) to cool them. The fuel conduit includes a nozzle injector (46) directed downstream towards the afterburner chamber (23).

Abstract: A turbine-nozzle vane fitted with a cooling system including a hollow airfoil (45) inserted between an outer deck and an inner deck (46). Disposed inside the airfoil (45) is a liner (60) which is fitted with a multi-perforated skirt to impact-cool the airfoil wall. The liner (60) has an inner wall (62) comprising a female frustum of a cone (66). A male frustum of a cone (64) is rigidly affixed to the inner deck (46) and is nested in the female frustum (66). These frusta provide communication between the inside of the liner (60) and the inside of the inner deck (46). Cooling air (70) is introduced into the liner (60) through the outer deck. A portion (71) of this air impact-cools the airfoil wall. Another portion (72) enters the inner deck (46) and passes through an orifice (67) to cool the turbine disks (49, 50) upstream and downstream of the nozzle.

Abstract: The invention relates to the control of air flows for cooling the axial walls of a high-temperature combustion chamber in which the walls are provided with through holes forming multiple perforations, and involves arranging the multiple perforations so that the cooling airflow permeability of the walls in the downstream zone of the chamber decreases in the downstream direction in order to compensate for the effects of the increase in pressure drop due to variation of the gas flow velocity. The invention is particularly applicable to sharply convergent combustion chambers such as twin-head combustion chambers.

Abstract: An afterburn device for a turbojet engine comprises a flame arrester formed by a plurality of radial arms distributed evenly around the rotational axis of the engine at the upstream end of the afterburn chamber. Each arm consists of a fixed rear part, and a front part which is separable from the rear part in a circumferential direction along a median joint plane, the front parts being carried on a ring which is rotatably mounted on the outer casing of the engine. Drive means is provided for rotating the ring between a first position for dry operation, and a second position for afterburn operation. In the first position the front and rear parts of the arms are aligned and joined to provide the arms with a streamlined, low-drag, zero angle of incidence profile suitable for dry operation.

Abstract: The output voltage of a Wheatstone bridge type electrical circuit compris four main resistances (J.sub.1 to J.sub.4) having substantially the same ohmic value, R, and substantially the same temperature coefficient of resistance, .alpha., is made independent of temperature differences existing between the branches of the bridge by addition, in each of the branches, of a compensation element (r.sub.1 to r.sub.4) in series with the main resistance, each compensation element being physically located very close to a main resistance situated in one of the adjacent branches of the bridge so as to have the same temperature as that main resistance. The compensation elements have the same ohmic value r and the same temperature coefficient of resistance .beta., with R.alpha.=r.beta., r being less than R and, preferably, r/R.ltoreq.1/2, so as to limit the loss of sensitivity of the Wheatstone bridge to variations in the resistances of the bridge.

Abstract: Two objects are articulated together by a strong and compact joint which provides two rotational degrees of freedom about axes X and Y, and which comprises a bearing have a male inner ring swivel mounted in a female outer ring. The male inner ring is rotatably mounted on a shaft integral with one of the objects and defining the axis X, and the female outer ring is attached to the other object. The two rings are rotationally linked in the direction of an axis Z perpendicular to the X and Y axes by two flat support surfaces on the inner ring arranged between two flat guide surfaces in the outer ring, the said support surfaces and the said guide surfaces being parallel to the X and Z axes.

Abstract: The present invention relates to a device for optically measuring the temperatures of cryogenic fluids or of moving surfaces in such fluids by analyzing the decay in the luminescence of a doped crystal, the device comprising a light source for exciting said crystal, an optical fiber for transporting the light flux emitted by said source to the crystal and for returning to a detection assembly the luminescent light emitted by the crystal as a result, and a measurement probe past which the fluid or the moving surface moves, wherein the doped crystal is constituted by one of the crystals from the group comprising strontium fluoride doped with divalent ytterbium, SrF.sub.2 :Yb.sup.2+ ; and calcium fluoride doped with divalent ytterbium, CaF.sub.2 :Yb.sup.2+.

Abstract: A soundproofing panel comprises a honeycomb core sandwiched between a solid skin and a porous skin, the cells of the honeycomb being divided in the direction of its thickness into at least two resonant cavities by a least one partition which is traversed by passages interlinking the cavities. The partitions are formed by a plurality of hollow microbeads having porous walls, the microbeads being bonded to one another and to the walls of the honeycomb at their points of contact. Such a soundproofing panel combines high performance in terms of linearity as a function of the level of sound excitation, attenuation band, bulk and mechanical strength.

Abstract: The invention proposes a process for bladder moulding thin articles made of a composite material consisting of fibre and polymerised resin, the articles comprising corners having a rounded vertex and produced by a shaper. Such a process is distinguished in that the surface experiencing the air pressure is convex and the normals to the surface converge on the rounded shaping vertex of the shaper.

Abstract: The system (13) for admitting external air (12) into a working section (11) of a gas turbine engine through a jacket (10) of the working section is characterised by the combination of doors (15) sliding towards the front (ramps) and rotating doors (14). The ramps (15) are fitted with grooved lateral arms (30) in which run wheels mounted on the doors (14). When they reach an ascending part (33) of the grooves (31) after sufficient movement of the ramps (15) towards the front, they are caused to rise, which opens the doors (14). This system can be used on double flow gas turbine engines for supersonic aircraft.

Abstract: A constant-speed twin spool turboprop unit including a twin spool gas generator having a low-pressure spool and a high-pressure spool each including a compressor and a turbine which drives the compressor, is described in which at least one propeller of the unit is driven by at least the high-pressure spool of the gas generator.

Abstract: The matrix of the composite material is made in sequenced manner by chemical vapor infiltration within fiber reinforcement. Each elementary sequence of the matrix comprises a relatively flexible layer and a relatively rigid ceramic layer, and the sequences are of thicknesses that increase going away from the reinforcing fibers, with the thickness at least of the first-deposited sequence being selected to be sufficiently small for the fibers to be coated in essentially individual manner. The flexible layers are made of an anisotropic material having sufficient capacity for elastic deformation in shear and transversely, and although a mainly ceramic character is conserved for the matrix, the thickness of the flexible layers is nevertheless selected to be sufficiently large to be capable of absorbing differential expansion of the components of the composite material while it is being made without inducing the existence of an initial network of cracks.

Abstract: Inducer equipment adapted to a pump having large induction capacity which cludes a case surrounding an inducer rotor having a plurality of blades leaving clearance relative to the case. The clearance between the peripheral portions of the blades and the case is of an increased value greater than the value of the normal clearance over a zone which extends both into a cylindrical first portion of the inside wall of the case upstream from the inducer rotor and into a portion of the inside wall of the case adjacent to the cylindrical first portion and overlapping an upstream portion of the inducer rotor over a distance from the leading edges of the blades of the inducer rotor. The ratio between the clearance of increased value and the clearance of normal value is advantageously greater than 10.

Abstract: A first satellite is placed practically directly by a launcher on a first final orbit. A second satellite is placed on the same launcher is initially transferred to a highly elliptical waiting orbit whose semi-major axis points to intercept the torus formed by the sphere of influence of the moon on its orbit, and then during a maneuver at the perigee of the highly elliptical orbit, the second satellite is transferred to lunar transfer orbit. Changes in the perigee altitude and the inclination of an intermediate orbit on which the second satellite is to be found are obtained mainly by gravitational reaction in the sphere of influence of the moon, and during a last maneuver, the second satellite is placed on a final orbit having orbital parameter values that are quite different from those of the orbital parameters of the first final orbit.

Abstract: A yarn is formed from discontinuous parallel fibers which are not twisted d which are held together by a covering yarn of sacrificial material wound around the fibers. The fibers comprise an intimate mixture of fibers of at least two different natures selected from carbon fibers or pre-oxidized polyacrylonitrile based carbon precursor fibers, or anisotropic or isotropic pitch based carbon precursor fibers, or phenolic or cellulosic based carbon precursor fibers, and ceramic fibers or ceramic precursor fibers. The mixture of fibers comprises, in its carbon state, at least 15% by weight of high strength fibers, having a tensile strength of at least 1500 MPa and a modulus of at least 150 MPa, and at least 15% by weight of fibers with a low Young's modulus of at most 100 GPa.

Abstract: A dry pump (32) has an inlet connected to the oven (10) for the purpose of establishing the desired low pressure conditions inside the oven and for extracting residual gas therefrom, a hydrolysis reactor (50) is connected to an outlet of the dry pump in order to receive residual gases coming from the oven, the hydrolysis reactor includes a first outlet (52) for solid deposits or for acid solutions coming from hydrolysis of the gases it receives, and it has a second outlet (54) for gas which is connected to the atmosphere. Gas injection means (46, 48) are located between the inlet of the dry pump (32) and the hydrolysis reactor (50) to prevent any backflow from the hydrolysis reactor towards the pump. Water feed means (74, 76) are connected to the hydrolysis reactor (50), at least via the second outlet (54) thereof, in order to put into solution the acid vapors that come from the hydrolysis reactor, thereby avoiding discharging them in the atmosphere.

Abstract: A thrust reverser is disclosed for a high bypass ratio turbofan jet engine having a fan cowling forming an outer boundary of an airflow duct and a jet engine structure including a jet engine cowling. The thrust reverser has a casing affixed to the jet engine structure, the casing having a plurality of attaching yokes. A first thrust reverser flap is pivotally connected to a corresponding one of the attaching yokes and is located rearwardly of an exit of the airflow duct, each first thrust reverser flap having a distal end and being movable between a forward thrust position, and a reverse thrust position. A second thrust reverser flap is pivotally connected to the distal end of a corresponding one of the first thrust reverser flaps and is also movable between a forward thrust position, and a reverse thrust position, wherein the second thrust reverser flaps also redirect air flow emanating from the air flow duct.

Abstract: A heating or cooling apparatus for a turbo-machine housing collar that adjusts the diameter of the housing using chambers that are arcs of a circle through which gas is blown onto the ribs of the housing. The gas circulates in a counterflow direction or in alternate directions for adjacent chambers in order to equalize the blowing conditions at every paint of the ribs.

Abstract: A combustion chamber is disclosed for a turbojet engine in which the combustion chamber has a forward intake, a rear exit and a perforated casing extending between the intake and exit. The combustion chamber also has at least two rows of insulating tiles arrayed on the casing in forward and rear rows with both rows extending circumferentially around the inner surface of the casing bounding the combustion chamber. Each rear tile has a forward edge portion with a sloping wall and each forward tile has a tapered rear edge portion overlapping the forward edge portion with a clearance therebetween such that the tampered rear edge portion and the sloping wall bound a slot opening into the combustion chamber and slanting towards the rear of the combustion chamber to facilitate the formation of an air cooling film on inner surfaces of the tiles.

Abstract: A system for inspecting internal zones of a machine, such as an engine, comprises an observation device having an optical fiber endoscope, and distribution and guide means including a network of flexible guide sheaths placed in the machine to define a number of different inspection routes along which the endoscope can be guided from an aperture in the machine wall to various predetermined critical internal zones. Preferably the system includes first electrical means implanted in each guide sheath and co-operable with second electrical means secured to the endoscope in order to detect the position thereof in the network and to transmit the position to a monitoring device outside the machine for monitoring and assisting the guidance of the endoscope in the network.