公开(公告)号：US11420759B2

公开(公告)日：2022-08-23

申请号：US17044178

申请日：2019-03-25

Applicant: JAPAN AEROSPACE EXPLORATION AGENCY

Inventor： Atsushi Ueno ,  Tatsunori Yuhara ,  Masashi Kanamori

IPC: F02K1/34 ,  B64C5/02 ,  B64C30/00 ,  B64D27/20 ,  B64D29/04

Abstract: [Object] To provide a supersonic aircraft and a method of reducing sonic booms, by which sonic booms due to engine exhaust can be reduced.
[Solving Means] A supersonic aircraft includes: a pair of engine nacelles 12R, 12L mounted on a fuselage 11 of an airframe 10; fins 13R, 13L as a pair of shielding plates that inhibits engine exhaust 15 discharged from jet engines (not shown) accommodated in the engine nacelles 12R, 12L from wrapping downward around the airframe 10; and a pair of horizontal tails 14R, 14L disposed behind the engine nacelles 12R, 12L. The fins 13R, 13L are disposed on the horizontal tails 14R, 14L so as to sandwich the engine exhaust 15, respectively.

公开(公告)号：US12017800B2

公开(公告)日：2024-06-25

申请号：US17042720

申请日：2019-02-21

Applicant: JAPAN AEROSPACE EXPLORATION AGENCY

Inventor： Tatsunori Yuhara

IPC: B64F5/10 ,  B64C23/04 ,  B64C30/00 ,  G06F30/15 ,  G06F111/10 ,  G06F113/28

CPC classification number: B64F5/10 ,  B64C30/00 ,  G06F30/15 ,  B64C23/04 ,  G06F2111/10 ,  G06F2113/28

Abstract: [Object] To realize an improvement in design accuracy and a reduction in design time in a process of matching an equivalent cross-sectional area of a design shape of a supersonic aircraft to a target equivalent cross-sectional area in a sonic boom reduction method based on an equivalent cross-sectional area.
[Solving Means] The technique includes: setting an initial shape of the airframe and a target equivalent cross-sectional area of the airframe; estimating a near field pressure waveform for the initial shape of the airframe assuming that the supersonic aircraft flies at a cruising speed; evaluating an equivalent cross-sectional area from the estimated near field pressure waveform for the initial shape of the airframe; and setting a Mach plane corresponding to the cruising speed, and setting a design curve on the Mach plane, the design curve corresponding to an initial curve at which the initial shape of the airframe and the Mach plane intersect so that the equivalent cross-sectional area approaches the target equivalent cross-sectional area. Then, the shape of the airframe is designed based on the design curve.

公开(公告)号：US11299253B2

公开(公告)日：2022-04-12

申请号：US16771414

申请日：2018-10-10

Applicant: JAPAN AEROSPACE EXPLORATION AGENCY

Inventor： Naoko Tokugawa ,  Tatsunori Yuhara

IPC: B64C3/14

Abstract: [Object] To provide a transonic airfoil capable of reducing pressure drag more than before, a wing having such an airfoil, and an aircraft including such a wing.
[Solving Means] An airfoil 11 has a shape in which a pressure coefficient Cp of a static pressure in a chord direction of a leading edge 12 of the airfoil 11 is −0.04 or less at z/c=0.015 (where z represents a coordinate in a direction perpendicular to an airflow direction within a plane that forms an airfoil, with a leading edge being as a reference (an upper wing surface direction is positive, and a lower wing surface direction is negative), and c represents a chord length). Thus, a pressure distribution has a sharp rise, which can decrease pressure drag.