Noise reduction method for weapon cabin of supersonic aircraft on basis of turbulent flow on front-edge surface

A weapon bay, supersonic technology, applied in the direction of affecting the air flow through the surface of the aircraft, aircraft parts, aircraft control, etc., can solve problems such as pressure self-sustained oscillation, and achieve the effect of avoiding disturbance, reliable function and convenient operation.

Active Publication Date: 2013-01-09
CHINA ACAD OF AEROSPACE AERODYNAMICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a noise reduction method for the weapon compartment of a supersonic aircraft based on the turbulence of the leadi

Method used

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  • Noise reduction method for weapon cabin of supersonic aircraft on basis of turbulent flow on front-edge surface
  • Noise reduction method for weapon cabin of supersonic aircraft on basis of turbulent flow on front-edge surface
  • Noise reduction method for weapon cabin of supersonic aircraft on basis of turbulent flow on front-edge surface

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Embodiment

[0037] The general flight altitude of the aircraft is 0km~15km, and the flight Mach number is 0~3. Simplify the weapon compartment into a rectangular square cavity, for example: the depth of the cavity is 150mm, the length is 450mm, and the aspect ratio is 3; the flight Mach number is set to 1.5, and the sea level value is used as a reference. The density is 1.225kg / m 3 , the flow temperature is 288.16K, then the dynamic viscosity coefficient is 1.7894×10 -5kg / (m s), the thickness of the boundary layer on the surface of the front edge of the square cavity is 5mm, based on the thickness of the boundary layer on the front edge of the square cavity Re δ The number is 1.73×10 5 .

[0038] 1) if image 3 , the thickness H of the disturbance plate is selected as 25% of the local boundary layer thickness of 5mm, that is, H=1.25mm.

[0039] 2) if image 3 , W represents the width of the perturbation sheet. The linear stability analysis method obtains the most unstable disturban...

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Abstract

A noise reduction method for a weapon cabin of a supersonic aircraft on the basis of turbulent flow on a front-edge surface includes steps of (1), acquiring the flight speed, the incoming flow density, the incoming flow temperature, an incoming flow viscosity coefficient and the thickness of a boundary layer of the front-edge surface of the weapon cabin according to the flight condition of the supersonic aircraft, and computing an incoming Reynolds number on the basis of the thickness of the boundary layer of the front-edge surface of the weapon cabin; (2), selecting a fundamental-frequency disturbance sheet; (3), computing the ratio of the length to the depth of the supersonic aircraft according to the length, the depth and the width of the weapon cabin of the supersonic aircraft, reducing the thickness H of the fundamental-frequency disturbance sheet by 10-20% if the ratio is larger than 4, or increasing the thickness H of the fundamental-frequency disturbance sheet by 10-20% if the ratio is not larger than 4; and (4), fixing the fundamental-frequency disturbance sheet on the supersonic aircraft to complete noise reduction for the weapon cabin of the supersonic aircraft on the basis of the turbulent flow on the front-edge surface. The noise reduction method has the advantage that the problem of severe self-sustained oscillation of pressure of the inside of the cabin after the buried weapon cabin is opened during supersonic flight of the supersonic aircraft can be effectively solved.

Description

technical field [0001] The invention relates to a noise reduction method for a weapon compartment of a supersonic aircraft based on turbulence on the surface of the leading edge, which is used for reducing severe noise and self-sustaining pressure oscillation in the weapon compartment when the aircraft with a built-in weapon compartment flies at supersonic speed. Background technique [0002] Weapon embedding is an inevitable development trend of supersonic vehicle weapon carrying methods. figure 1 It is a schematic diagram of the fighter's internal weapon bay and weapon mounts. The figure describes the structural composition of the weapon bay when the door is opened. When the aircraft is flying at supersonic speed, after opening the weapon compartment, as indicated figure 2 (a), the high-speed airflow flows over the surface of the weapon compartment and mixes with the air in the compartment to form a shear layer, and the shear layer vortices interact with the rear edge of...

Claims

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Application Information

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IPC IPC(8): B64C23/00
Inventor 冯峰郭欣王强
Owner CHINA ACAD OF AEROSPACE AERODYNAMICS
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