US 12,110,841 B2
Supersonic aircraft and method of reducing sonic booms and jet noise
Junichi Akatsuka, Tokyo (JP)
Assigned to Japan Aerospace Exploration Agency, Tokyo (JP)
Filed by JAPAN AEROSPACE EXPLORATION AGENCY, Tokyo (JP)
Filed on Feb. 22, 2022, as Appl. No. 17/652,054.
Claims priority of application No. 2021-027126 (JP), filed on Feb. 24, 2021; and application No. 2022-015476 (JP), filed on Feb. 3, 2022.
Prior Publication US 2022/0268236 A1, Aug. 25, 2022
Int. Cl. F02K 1/44 (2006.01); B64C 5/02 (2006.01); B64C 30/00 (2006.01); F02K 1/12 (2006.01); F02K 1/34 (2006.01); F02K 1/42 (2006.01); F02K 1/46 (2006.01)
CPC F02K 1/44 (2013.01) [B64C 5/02 (2013.01); B64C 30/00 (2013.01); B64D 33/06 (2013.01); F02K 1/12 (2013.01); F02K 1/42 (2013.01); F02K 1/46 (2013.01); F05D 2220/80 (2013.01); F05D 2260/96 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A supersonic aircraft, comprising:
a shield that shields an engine exhaust flow discharged from a jet engine accommodated in an engine nacelle mounted on a fuselage of the aircraft to thereby reduce sonic booms due to the engine exhaust flow; and
an exhaust nozzle that is provided in an exhaust port of the engine nacelle and that is configured to generate a sound source for high-frequency components of jet noise at a position at which the shield is capable of shielding the high-frequency components of jet noise due to the engine exhaust flow, to thereby reduce the high-frequency components of jet noise, and is configured to promote mixing of low-frequency components of jet noise due to the engine exhaust flow with an external air flow to thereby reduce the low-frequency components of jet noise,
wherein the exhaust nozzle extends to the rear of the jet engine and constitutes an exhaust flow path,
wherein the exhaust nozzle has a plurality of main nozzle pieces and at least one coupling nozzle piece,
wherein a rear end portion of each of the main nozzle pieces is provided swingably in an inward and outward direction of the exhaust flow path about an open/close bend section, the open/close bend section being formed at a rear end of a throttle section at the rear of the jet engine,
wherein the coupling nozzle piece is disposed between adjacent main nozzle pieces and is coupled bendably to the main nozzle pieces on either side thereof, the coupling nozzle piece being coupled bendably to the main nozzle pieces at a side bend section, and the coupling nozzle piece having a central bend section that is capable of forming a plurality of projecting sections inside the exhaust flow path in conjunction with a movement of each of the main nozzle pieces,
wherein, when the main nozzle pieces are swung outward from the exhaust flow path, the coupling nozzle piece forms a flat surface having no projecting section inside the exhaust flow path, and the cross-sectional area of the exhaust flow path is wider toward the rear end portion of the main nozzle pieces from the position of the open/close bend section, and
wherein, when the main nozzle pieces are swung inside the exhaust flow path, the coupling nozzle piece forms a projecting section inside the exhaust flow path along the exhaust flow path for narrowing the exhaust flow path.