Abstract: An assembly comprising first and second parts made of composite material held one against the other by at least one fastener system comprising a bolt having a flat head from which there extends a threaded portion, and a nut having a flat head from which there extends a shank including tapping suitable for co-operating with the threaded portion of the bolt. The head of the bolt bears against a countersink formed in the first part. The head of the nut bears against a countersink formed in the second part. The fastener system is suitable, during axial expansion of the fastener system, for causing each head to tilt towards the countersink in which it is housed.

Abstract: A high-gain optical amplifier for a wave to be amplified at a wavelength referred to as the emission wavelength, includes: optical pumping elements (4) producing a pump wave at a wavelength referred to as the pump wavelength; a solid amplifying medium (1) that is doped with active ions, the solid amplifying medium being capable of emitting laser radiation at the emission wavelength when the medium is pumped by the pumping elements; cooling elements (2) capable of cooling the solid amplifying medium to a temperature of no higher than 250 Kelvin; and optical multiplexing elements capable of coupling together the pump wave and the wave to be amplified in the amplifying medium. The amplifying medium has Stark sublevels contained within a spectral domain ranging over less than 200 cm?1 (approximately 20 nm, when expressed in wavelength). A laser including a resonant optical cavity and an amplifier are also described.

Abstract: An assembly comprising first and second parts made of composite material held one against the other by at least one fastener system comprising a bolt having a flat head from which there extends a threaded portion, and a nut having a flat head from which there extends a shank including tapping suitable for co-operating with the threaded portion of the bolt. The head of the bolt bears against a countersink formed in the first part. The head of the nut bears against a countersink formed in the second part. The fastener system is suitable, during axial expansion of the fastener system, for causing each head to tilt towards the countersink in which it is housed.

Abstract: A high-gain optical amplifier for a wave to be amplified at a wavelength referred to as the emission wavelength, includes: optical pumping elements (4) producing a pump wave at a wavelength referred to as the pump wavelength; a solid amplifying medium (1) that is doped with active ions, the solid amplifying medium being capable of emitting laser radiation at the emission wavelength when the medium is pumped by the pumping elements; cooling elements (2) capable of cooling the solid amplifying medium to a temperature of no higher than 250 Kelvin; and optical multiplexing elements capable of coupling together the pump wave and the wave to be amplified in the amplifying medium. The amplifying medium has Stark sublevels contained within a spectral domain ranging over less than 200 cm?1 (approximately 20 nm, when expressed in wavelength). A laser including a resonant optical cavity and an amplifier are also described.

Abstract: An annular combustion chamber has an inner wall and an outer wall of ceramic matrix composite material, together with a chamber end wall that is connected to the inner and outer walls. Elastically-deformable link elements connect the inner wall and the outer chamber walls to inner and outer metal casings. Each of the inner and outer chamber walls is subdivided circumferentially into adjacent sectors along longitudinal edges, each sector extending continuously from the end wall to the opposite end of the chamber and being folded outwards from the chamber at each of its longitudinal edges to form a portion having a U-shaped cross-section terminated by a folded-back margin that is spaced apart from the outer face of the corresponding chamber wall. The link elements are connected to the inner and outer chamber walls by being fastened to the sector margins.

Abstract: An assembled annular combustion chamber comprises an annular inner wall and an annular outer wall made of ceramic matrix composite material together with a chamber end wall connected to the inner and outer walls and provided with orifices for receiving injectors. Elastically-deformable link parts connect the inner wall and the outer wall of the chamber to inner and outer casings that are made of metal. The assembly formed by the inner wall, the outer wall, and the combustion chamber end wall is subdivided circumferentially into adjacent chamber sectors, each sector being made as a single piece of ceramic composite material and comprising an inner wall sector, an outer wall sector, and a chamber end wall sector. The link parts connect the inner metal casing and the outer metal casing respectively to each inner wall sector of the combustion chamber and to each outer wall sector of the chamber. The chamber end wall sectors are in contact with a one-piece ring to which they are connected.

Abstract: An assembled annular combustion chamber comprises an annular inner wall and an annular outer wall made of ceramic matrix composite material together with a chamber end wall connected to the inner and outer walls and provided with orifices for receiving injectors. Elastically-deformable link parts connect the inner wall and the outer wall of the chamber to inner and outer casings that are made of metal. The assembly formed by the inner wall, the outer wall, and the combustion chamber end wall is subdivided circumferentially into adjacent chamber sectors, each sector being made as a single piece of ceramic composite material and comprising an inner wall sector, an outer wall sector, and a chamber end wall sector. The link parts connect the inner metal casing and the outer metal casing respectively to each inner wall sector of the combustion chamber and to each outer wall sector of the chamber. The chamber end wall sectors are in contact with a one-piece ring to which they are connected.

Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm?1 and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: An annular combustion chamber has an inner wall and an outer wall of ceramic matrix composite material, together with a chamber end wall that is connected to the inner and outer walls. Elastically-deformable link elements connect the inner wall and the outer chamber walls to inner and outer metal casings. Each of the inner and outer chamber walls is subdivided circumferentially into adjacent sectors along longitudinal edges, each sector extending continuously from the end wall to the opposite end of the chamber and being folded outwards from the chamber at each of its longitudinal edges to form a portion having a U-shaped cross-section terminated by a folded-back margin that is spaced apart from the outer face of the corresponding chamber wall. The link elements are connected to the inner and outer chamber walls by being fastened to the sector margins.

Abstract: A support arm (13) is intended to be installed in a radial position in an afterburner device of a bypass turbojet. The device comprises first and second inner annular casings defining a passage for a primary flow and an outer annular casing defining together with the first inner annular casing a passage for a secondary flow. The arm (13) comprises a monobloc structure made of composite material including two integral walls (14, 15), on the one hand, designed to define a groove (16) having a substantially V-shaped profile and, on the other hand, including first end parts (17) joined together and adapted to define a foot (18) and second end parts (19) adapted each to define at least one flange (20, 21) intended to be positively connected to the outer annular casing.

Abstract: A support arm (13) is intended to be installed in a radial position in an afterburner device of a bypass turbojet. The device comprises first and second inner annular casings defining a passage for a primary flow and an outer annular casing defining together with the first inner annular casing a passage for a secondary flow. The arm (13) comprises a monobloc structure made of composite material including two integral walls (14, 15), on the one hand, designed to define a groove (16) having a substantially V-shaped profile and, on the other hand, including first end parts (17) joined together and adapted to define a foot (18) and second end parts (19) adapted each to define at least one flange (20, 21) intended to be positively connected to the outer annular casing.

Abstract: In a turbomachine comprising an annular shell of metal material containing in a gas flow direction F: a fuel injection assembly; an annular combustion chamber of composite material; and an annular nozzle of metal material forming the inlet stage with fixed blades of a high pressure turbine, provision is made for the combustion chamber to be held in position inside the annular metal shell by a plurality of flexible metal tongues each comprising three branches connected together in a star configuration, the ends of two of these three branches being fixed securely to a downstream end of the combustion chamber via respective first and second fixing means, and the end of the third branch being fixed securely to the annular shell via third fixing means.

Abstract: In a turbomachine comprising an annular shell of metal material containing in a gas flow direction F: a fuel injection assembly; an annular combustion chamber of composite material; and an annular nozzle of metal material forming the inlet stage with fixed blades of a high pressure turbine, provision is made for the combustion chamber to be held in position inside the annular metal shell by a plurality of flexible metal tongues each comprising three branches connected together in a star configuration, the ends of two of these three branches being fixed securely to a downstream end of the combustion chamber via respective first and second fixing means, and the end of the third branch being fixed securely to the annular shell via third fixing means.

Abstract: A steerable nozzle for a reaction engine comprises a fixed portion (1) for fixing to the engine, a moving portion (2) hinged to the fixed portion, control means (3) for controlling the moving portion, and one or more resilient assemblies (4) disposed between the fixed portion and the moving portion. The nozzle is characterized in that each resilient assembly comprises at least one fixed resilient stud (40) having a first end secured to the fixed portion and a second end, opposite from the first end, secured to a rigid piece (42); and at least one moving resilient stud (41) having a first end secured to the moving portion and a second end, opposite from the first end, secured to said rigid piece (42). In addition, each moving resilient stud (41) is offset relative to each fixed resilient stud (40) in a circumferential direction of the nozzle.

Abstract: A steerable nozzle for a reaction engine comprises a fixed portion (1) for connection to the engine, a plurality of steerable flaps (21) mounted on one end (11) of the fixed portion, and flap steering means (3, 4, 22, 31). The nozzle is characterized in that the flap steering means comprise a resilient ring (3) having a first circumference secured to said end (11) of the fixed portion and a second circumference connected to the flaps (21), and control means (4) for moving the second circumference of the resilient ring.

Abstract: A fitting (22) connected to an actuator member (18a) is mounted on a diverging portion (12) by means of inserts (32) designed to be placed and held in the wall of the diverging portion, and fixing means which comprises an elastically-deformable element (24) designed to compensate for any dimensional variations of thermal origin to maintain a force pressing the fitting (22) against the diverging portion (12). A thrust element (26) is connected to the inserts (32) in such a manner as to compress the elastically-deformable element (24) between the thrust element (26) and the fitting (22).