Aerodynamic layout of a high-altitude long-endurance tandem wing aircraft using dihedral difference

An aerodynamic layout and aircraft technology, applied in aircraft, motor vehicles, transportation and packaging, etc., can solve the problems of large moving range of the aerodynamic focus of the whole aircraft, affecting flight performance, adverse interference of rear wings, etc., to enhance the ability to use in the battlefield environment, Large wing area, the effect of improving the overall aerodynamic characteristics

Active Publication Date: 2019-06-18
BEIHANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to meet the requirements of high-altitude and long-endurance aircraft with sufficient lift, a tandem wing aerodynamic layout has appeared. This layout includes two wings, the rear wing will interfere with the front wing, but the front wing will have adverse effects on the rear wing. interference
In addition, when the overall angle of attack changes, the aerodynamic interference intensity between the wings changes, so that the lift increment of each wing will not change proportionally, resulting in a large range of movement of the aerodynamic focus of the whole aircraft, which affects flight performance

Method used

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  • Aerodynamic layout of a high-altitude long-endurance tandem wing aircraft using dihedral difference
  • Aerodynamic layout of a high-altitude long-endurance tandem wing aircraft using dihedral difference
  • Aerodynamic layout of a high-altitude long-endurance tandem wing aircraft using dihedral difference

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Embodiment

[0026] Example: Figure 5 Provided is the three-dimensional analysis curve of the change of the overall lift-drag ratio with the angle of attack of the layout of the present invention with the front wing 2 upside down 5° and the rear wing 3 downside 5° compared to the common tandem wing layout. The ordinate LDR is the lift-drag ratio, and the abscissa AOA is the angle of attack, fp5-bp-5 is the layout of the present invention's front wing 2 upside-down 5° and rear wing 3 downside 5°, h0c-3D is a common tandem wing layout, wherein each wing uses NACA4412 airfoil, the average The chord length is 0.75m and the aspect ratio is 26.7. It can be seen that when the front and rear wings of the layout in the present invention have an appropriate up-and-down dihedral difference, the unfavorable induction effect of the front wing tip vortex on the aerodynamic performance of the rear wing can be effectively improved, which is conducive to improving the overall aerodynamic performance of th...

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Abstract

The invention discloses an aerodynamic layout for a high altitude long endurance serial wing aircraft by adopting a difference of upper and lower dihedral angles and belongs to the field of aerodynamic layout design of the aircraft. In the aerodynamic layout of the aircraft, a cylindrical section fuselage, front wings and rear wings at higher aspect ratio and V-shaped empennages are adopted by the aircraft, wherein the front wings are arranged as high wings, have upper dihedral angles and are symmetrically mounted on a front half section of the fuselage; the rear wings are arranged as low wings, have lower dihedral angles and are symmetrically mounted on a rear half section of the fuselage; two V-shaped empennages are arranged, are symmetrically mounted on the rear half section of the fuselage and have upper dihedral angles at 45 DEG C; a fanjet is arranged above the tail part of the fuselage. According to the invention, under the condition that the same wing area is guaranteed, a shorter span is adopted, the structure efficiency is increased, the requirement for the airport landing condition is reduced and the use capacity of the battlefield environment is enhanced; larger spans are adopted by the front wings and shorter spans are adopted by the rear wings; the beneficial interference of the rear wings to the front wings is fully utilized; the harmful interference of the front wings to the rear wings is reduced.

Description

technical field [0001] The invention belongs to the field of aircraft aerodynamic layout design, and in particular relates to an aerodynamic layout of a high-altitude long-endurance tandem wing aircraft in which the front and rear wings adopt an up-down dihedral difference. Background technique [0002] High-altitude long-endurance aircraft can complete military tasks such as long-range reconnaissance, target surveillance, communication relay, electronic jamming, and high-altitude early warning. It is the basis for building a high-altitude strategic and tactical platform and has important strategic and tactical significance. However, high-altitude long-endurance aircraft has high requirements on flight performance and aerodynamic quality, especially a large lift-to-drag ratio under the premise of sufficient lift. [0003] For fixed-wing aircraft with subsonic conventional layout, in order to obtain a higher lift-to-drag ratio during design, since the wing is its main lift co...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B64C39/08
CPCB64C39/08
Inventor 蒋崇文林宏渊罗磊万志强高振勋
Owner BEIHANG UNIV
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