Sound attenuation device for two-propeller turboprop engine of aircraft, has actuators mounted in walls of unducted fan blades and delivering signal leading to sound attenuation in response to control signal provided by controller

• Main Authors: MOREL CEDRIC, VUILLEMIN ALEXANDRE, ALFRED, GASTON
• Format: Patent
• Language: English; French
• Published: 21.09.2012
• Subjects: ACOUSTICS; ACOUSTICS NOT OTHERWISE PROVIDED FOR; AEROPLANES; AIRCRAFT; ARRANGEMENTS OR MOUNTING OF POWER PLANTS OR PROPULSIONTRANSMISSIONS IN AIRCRAFT; AVIATION; BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; COSMONAUTICS; ENGINE PLANTS IN GENERAL; EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLYING SUITS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; HELICOPTERS; INDEXING SCHEME FOR ASPECTS RELATING TONON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES ORJET-PROPULSION PLANTS; INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUSSUBCLASSES OF CLASSES F01-F04; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING,NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; MUSICAL INSTRUMENTS; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; PARACHUTES; PERFORMING OPERATIONS; PHYSICS; SOUND-PRODUCING DEVICES; STEAM ENGINES; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TRANSPORTING; WEAPONS

The device has error sensors (20) mounted on an outer surface of a nacelle (14) for sensing a surrounding sound signal (S-E). Actuators (18) are mounted in walls of unducted fan blades (16) and deliver a signal leading to sound attenuation in response to a control signal (S-C). A controller (22) is connected to the sensors and the actuators, and generates the control signal. Each actuator has a membrane housed in an opening formed in the corresponding blade, and a piezoelectric element connected to the membrane to vibrate the membrane, where the membrane is made of metal or composite material. L'invention concerne un dispositif d'atténuation acoustique du bruit d'hélice d'un turbopropulseur d'aéronef à double hélice, le turbopropulseur comprenant une nacelle (14), un ensemble amont (16a) et un ensemble aval (16b) de pales de soufflante (16) non carénées disposés à l'arrière de la nacelle. Le dispositif comporte une pluralité de capteurs d'erreur (20) montés sur une surface externe de la nacelle, lesdits capteurs étant aptes à capter un signal acoustique environnant, une pluralité d'actionneurs (18) montés chacun en paroi d'une pale de soufflante, lesdits actionneurs étant aptes à délivrer un signal conduisant à une atténuation acoustique en réponse à un signal de commande (S ), et un contrôleur (22) relié aux capteurs d'erreur et aux actionneurs, ledit contrôleur étant apte à générer le signal de commande.