Abstract: The present disclosure is directed to a rotary wing rotor comprising one or more blades. Each blade has a torsion frequency around its span being substantially equal to a rotation frequency (?) of the rotor; torsion means twist to the rotation frequency of the rotor, in synchronization with said rotation; and comprising a material configured to dampen the torsion resonance, so as to avoid the resonance divergence.

Abstract: The invention applies to doubly resonant optical parametric oscillators comprising a non-linear crystal (4) through which pass a pump laser beam (fp), a signal beam (fs), and a complementary beam (fc), and a device (5) that totally or partially reflects said beams emanating from the crystal such that, after reflection, they generate between them a relative phase-shifting value ??ar for a given functioning mode independent of the signal frequency or complementary frequency, and is characterized in that the reflecting device (5) is a metallic minor, or a combination of two scattering mirrors and a multilayer dielectric mirror placed downstream.

Abstract: A method for forming a protective coating containing aluminum on the surface of a metal part, wherein the part is contacted with a carburizer made of an aluminum alloy, at a treatment temperature and in a chamber, the atmosphere of which contains an active gas which reacts with the carburizer to form a gaseous aluminum halide, which decomposes upon contacting the part while depositing aluminum metal thereon. In the method the aluminum alloy of the carburizer includes at least one element, zirconium and/or hafnium, the active gas reacting with the carburizer to also form a halide of the reactive element which decomposes upon contacting the part while depositing the element thereon at the same time as the aluminum.

Abstract: The invention relates to a tip indenting apparatus for testing a block of material, characterized in that it comprises: a holder for the tip and a holder for a block of a material to be punched or scratched, said tip holder and said block holder each comprising a solid body made of heat conducting material; securing means for removably securing the tip or the block in thermal-conducting contact to said solid body; an annular sheath having a shape corresponding to that of said solid body and in which said solid body is provided; heating means comprising at least one electric heater; and means for assembling the solid body and the heating means; wherein, during a test, the tip can be heated at a predetermined temperature, in particular a temperature essentially equal to that of the block of material to be tested.

Abstract: A process for measuring speed or vibration characteristics using a LIDAR device allows the separation of a useful contribution and an interfering contribution in a backscattered signal. To this purpose, a phase characteristic of an optical wave emitted in the direction of a target volume is modulated. The interfering contribution, which originates from a source at a distance from the target volume, appears with variable shifts of said phase characteristic in a heterodyne detection signal. An accumulation then isolates the useful contribution, from which a result is obtained for the speed or vibration measurement. The process can be implemented with a frequency modulation or phase modulation of the optical wave.

Abstract: The present disclosure relates to a compact wide field imaging system for the infrared spectrum range, the system including a vacuum housing with a porthole, a cooled dark room arranged inside the vacuum housing and provided with an opening referred to as a cold diaphragm, an infrared detector arranged inside the cooled dark room, and a device for the optical conjugation of the field rays with the detector. In the system, the optical conjugation device does not include any element located outside the vacuum housing, and includes at least one cold lens located inside the cooled dark room, the pupil of the optical conjugation device coinciding with the cold diaphragm.

Abstract: The invention relates to a method of producing and joining superalloy balls by means of brazing and to objects produced with such joints. According to one aspect of the invention, an alloy powder covered with a brazing solder is bonded to a spherical core and subsequently transformed into a continuous alloy layer by means of brazing.

Abstract: A structural element used for attenuating aviation turbine noise is provided with pores (1, 2) embodied in the form of cylindrical channels which are open on the first ends inside the turbine housing and closed on the opposite ends thereof, wherein the diameter (D) of each channel ranges approximately from 0.1 to 0.3 mm, each channel is remote at least along one part of the length thereof from the closest neighbors at a minimum distance ranging approximately from 0.02 to 0.3 mm and the ratio between the channel length and diameter thereof is of the order of 102.

Abstract: A process for measuring speed or vibration characteristics using a LIDAR device allows the separation of a useful contribution and an interfering contribution in a backscattered signal. To this purpose, a phase characteristic of an optical wave emitted in the direction of a target volume is modulated. The interfering contribution, which originates from a source at a distance from the target volume, appears with variable shifts of said phase characteristic in a heterodyne detection signal. An accumulation then isolates the useful contribution, from which a result is obtained for the speed or vibration measurement. The process can be implemented with a frequency modulation or phase modulation of the optical wave.

Abstract: The method comprises positioning a diffraction grating with a two-dimensional meshing on the path of the beam to be analyzed and processing at least two interferograms of at least two different colors, each interferogram being obtained in a plane from two sub-beams with different diffraction orders. The invention can be used to analyze and correct divided wavefronts.

Abstract: System (10) for detecting the position of a mobile or immobile entity (20) in a defined space (30), characterised in that it includes: means (40) of detecting the presence of said entity in at least two partially overlapping observation areas (Z1, Z2) of said space, said means being adapted for collecting at least one piece of immobile presence information (Ip) and one piece of movement information (Im) of said entity in each of said observation areas, processing means (50) which are adapted for carrying out logic operations on at least a portion of said information collected for each of said observation areas, decision means (60), which are connected to the processing means and adapted for controlling an action on the basis of a logic signal generated by the processing means.

Abstract: A method and a system for analyzing the wavefront of a light beam, wherein a diffraction grating is arranged in a plane perpendicular to the light beam to be analyzed and optically conjugated to the analysis plane. Different emerging beams of the grating interfere to generate an image having deformations linked to the gradients of the wavefront to be analyzed. The method is characterized in that the grating carries out the multiplication of an intensity function which is implemented by a two-dimensional grating with hexagonal meshing of surface S transmitting the light of the beam to be analyzed into plural emerging beams arranged in a hexagonal meshing, by an phase function which is implemented by a two-dimensional grating with hexagonal meshing of surface 3S which introduces a phase shift close to 2?/3 (modulo 2?) between two adjacent secondary beams.

Abstract: The invention relates to an elongated, torsion-deformable aerodynamic element, in which the upper surface (2) is continuous while the lower surface (3) comprises a longitudinal slot (6) in the direction of the span and in the vicinity of the leading edge (4). Furthermore, an actuator device (14) inside said aerodynamic element is capable of sliding the edges (6A and 6R) of the slot (6) relative to each other.

Abstract: The invention relates to a three-dimensional sheet structure characterised in that it comprises at least: a first sheet (1) comprising a plurality of first ribs (3) on one surface thereof; and a second sheet (2) including on one surface thereof a plurality of second ribs (6) intersected by flutes (9) having a shape complementary to that of the first ribs (3) of said first sheet (1); and in that said first and second sheets (1, 2) are superimposed and attached together, each of said first ribs (3) of said first sheet (1) being received in one of said flutes (9) of said second sheet (2).

Abstract: The invention relates to a tip indenting apparatus for testing a block of material, characterized in that it comprises: a holder for the tip and a holder for a block of a material to be punched or scratched, said tip holder and said block holder each comprising a solid body made of heat conducting material; securing means for removably securing the tip or the block in thermal-conducting contact to said solid body; an annular sheath having a shape corresponding to that of said solid body and in which said solid body is provided; heating means comprising at least one electric heater; and means for assembling the solid body and the heating means; wherein, during a test, the tip can be heated at a predetermined temperature, in particular a temperature essentially equal to that of the block of material to be tested.

Abstract: The invention relates to a method of estimating at least one deformation of the wave front of an observation system or of an object observed by said observation system, characterized in that: at least one diversity image is acquired, in the vicinity of the focal plane of the observation system, in at least one diversity plane, the diversity image comprising a known diversity deformation; and in that in each diversity plane, an image model is determined based on at least one decomposition of the physical pupil of the system into a plurality of subpupils; a decomposition over each subpupil of the sought-after deformation in the form of at least one known deformation weighted by coefficients to be determined; a determination of the transfer function of the system by autocorrelation of its pupil; the linearization of each of the terms of the autocorrelation as a function of the coefficients of the sought-after deformation, the linearization being performed in the vicinity of the known diversity deformation; the o

Abstract: The invention relates to a method of brazing a Ti—Al alloy. According to the invention, a layer of nickel (2) is disposed between a part (1) which is made from titanium aluminide and a brazing sheet (3), such as to enable: the aforementioned part (1) to be brazed to another metallic material (4) without the aluminium diffusing from one to the other; and a stable link with good mechanical strength to be produced. The invention can be used for the assembly of aircraft engine parts which are made from titanium aluminide and nickel-based superalloy.

Abstract: The present invention relates to a sandwich-structure flat active actuator that is symmetrical relative to the mid-plane comprising at least one piezoelectric flat layer having an active direction superpose and fixedly attached to at least one passive flat layer of fabric with rigid warp and weft oriented in two directions forming a mesh; the two directions of each layer of fabric are the same. The active direction of each piezoelectric layer is oriented along one and the same diagonal of the mesh of the layers of fabric. The invention is also aimed at a device consisting of two actuators mounted head-to-tail. The invention applies to the active torsion of structures such as, for example, a helicopter blade.

Abstract: The engine comprises a low pressure stage (1) and a high pressure stage (2) with two independent rotors (3,4) and associated fixed fluid preparation members (9,10,13,14), combining “compressor” means (15,16) and “expander” means (17,18) and at least one combustion chamber (19,20) in a central volume defined axially by the rotors (3,4) and laterally by three substantially cylindrical, coaxial walls (22,23,24), defining in pairs an outer duct (25) connecting the outlet of the LP compressor (15) to the inlet of the HP compressor (16) and an inner duct (26) connecting the outlet of the HP compressor (16) to the inlet of a first combustion chamber (19), whose outlet supplies the HP expander (18) with gases produced by combustion guided to the inlet of the LP expander (17), whose outlet is in communication with the outside via at least one exhaust opening (41) for the combustion gases.

Abstract: This relates to an improvement to the process of aluminization or activated cementation in which a donor cement containing the aluminium is attacked at high temperature and in a neutral or reducing atmosphere by a gaseous ammonium halide to form a gaseous aluminium halide which decomposes on contact with a nickel-based substrate depositing aluminium metal thereon. According to the invention the aluminium halide is at least partly replaced by a zirconium halide leading to the inclusion of zirconium in the deposit. Improvement in the protection of the hot parts of aircraft engines made of nickel-based superalloy. No figure is to be published.