Sawtooth-shaped aircraft weapon cabin noise suppression device

Abstract

The invention discloses a sawtooth-shaped aircraft weapon cabin noise suppression device. The device comprises a spoiler arranged on the front edge surface of a weapon cabin. The spoiler comprises a bottom face base plate and a spoiler sheet connected with the bottom face base plate. The spoiler sheet can rotate around the bottom face base plate through connecting points. The included angle between the rotating spoiler sheet and the bottom face base plate is any angle between 0 degree and 90 degrees. The upper surface and the lower surface of a crossbeam of the spoiler sheet are each of a sawtooth-shaped structure, and an incoming flow control effect can be greatly improved. The projected area of the device in the incoming flow normal direction is reduced through a gap in the bottom of thespoiler sheet, so that the aerodynamic drag of an aircraft is reduced. The inclination angle between the spoiler sheet and the base plate is changed, so that it is guaranteed that the height of the spoiler sheet is equivalent to the boundary layer thickness, and the best noise reduction effect on a downstream cabin can be achieved under different speed conditions.

Description

Technical field [0001] The invention relates to the field of aerospace technology, in particular to a sawtooth-shaped aircraft weapon bay noise suppression device. Background technique [0002] The built-in weapon bay is one of the main features of modern advanced fighters. The door is always closed when the fighter takes off / landing, cruises, etc., to maintain the fighter’s excellent aerodynamic shape, thereby reducing flight resistance, enhancing maneuverability, and enhancing stealth effect. When a fighter launches or releases weapons, the door of the weapon compartment is open, and the high-speed external airflow hits the rear wall of the weapon compartment, which will cause self-sustained oscillations in the compartment, thereby generating high-intensity aerodynamic noise in the compartment. The high-intensity noise environment not only fatigues the cabin structure and affects its service life, but also causes great harm to the health of equipment and personnel. [0003] At ...

AI Technical Summary

Problems solved by technology

Active flow control changes the flow mode of airflow by installing jet or plasma devices inside and outside the cabin, thereby suppressing the generation of noise in the cavity. However, these devices are more complicated and have poor applicability; while passive flow control mainly uses Spoilers are installed on the front edge to change the position and speed of the shear layer in the cabin, weakening the impact on the cabin, so as to achieve the purpose of suppressing the noise in the cabin

[0004] Among them, installing sawtooth spoilers on the leading edge of the cabin is a simple and effective noise suppression method. However, while controlling the flow, the sawtooth structure also destroys the aerodynamic shape of the aircraft, thereby increasing the aerodynamic resistance of the aircraft.

In addition, studies have shown that when the height of the leading edge serrations is equal to the thickness of the incoming boundary layer at the leading edge of the cabin, the noise suppression effect in the cabin is the best, and the thickness of the incoming boundary layer is not the same under different flight conditions. Therefore, the existing Fixed-height sawtooths produce optimal noise reduction only under certain flight conditions

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