The discovery and prediction of vortex flow aerodynamics

AbstractHigh-speed aircraft often develop separation-induced leading-edge vortices and vortex flow aerodynamics. In this paper, the discovery of separation-induced vortex flows and the development of methods to predict these flows for wing aerodynamics are reviewed. Much of the content for this article was presented at the 2017 Lanchester Lecture and the content was selected with a view towards Lanchester’s approach to research and development.

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On the Breakdown at High Incidences of the Leading Edge Vortices on Delta Wings

Journal of the Royal Aeronautical Society ◽

10.1017/s0368393100073314 ◽

1960 ◽

Vol 64 (596) ◽

pp. 491-493 ◽

Cited By ~ 19

Author(s):

B. J. Elle

Keyword(s):

High Speed ◽

CuBr-усилитель яркости с частотой следования импульсов сверхизлучения/усиления до 200 kHz

Письма в журнал технической физики ◽

10.21883/pjtf.2021.17.51380.18842 ◽

2021 ◽

Vol 47 (17) ◽

pp. 18

Author(s):

И.С. Мусоров ◽

С.Н. Торгаев ◽

Г.С. Евтушенко

Keyword(s):

Research And Development ◽

Active Medium ◽

High Voltage ◽

High Speed ◽

Pulse Repetition Frequency ◽

Leading Edge ◽

Input Energy ◽

Discharge Mode ◽

Copper Bromide ◽

Half Height

The paper presents the results of research and development of a high-speed brightness amplifier based on copper bromide vapor active medium, with a pulse repetition frequency of up to 200 kHz. This became possible due to the use of the reduced input energy into the discharge mode (less than 60 µJ / cm3 per pulse), by shortening the leading edge of the high-voltage pump pulse to 20 ns and the duration (at half-height) to 30 ns.

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Control of Leading Edge Vortices Using Apex Flap over Non-Slender Delta Wing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.390.12 ◽

2013 ◽

Vol 390 ◽

pp. 12-17

Author(s):

Hafiz Laiq-Ur Rehman

Keyword(s):

Vortex Flow ◽

Vortex Breakdown ◽

Delta Wing ◽

Leading Edge ◽

Pressure Probe ◽

Sweep Angle ◽

Strong Shear ◽

Flap Deflection ◽

Probe Measurements ◽

Leading Edge Vortices

This manuscript presents the vortex flow structure over non-slender delta wing with leading edge sweep angle, Λ=45°. A comprehensive investigation has been conducted in wind tunnel at Reynolds number ranging from, Re = 247,000 - 445,000. Seven-hole pressure probe measurements for axial vorticity, axial velocity, vortex trajectory and pressure variations are presented at various chordwise stations and angles of incidences. It was demonstrated that weak leading edge vortices are generated very close to the wing surface with strong shear layer which move upward and outboard with apex flap deflection. Reattachment line move towards wing root chord with the increase in angle of attack. Passive apex flap has been used to control the leading edge vortices and to delay the vortex breakdown. It is recognized that vortex breakdown was delayed by 8% by downward apex flap deflection.

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Unsteady Characteristics of Breakdown Vortices over Delta Wing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.66-68.1874 ◽

2011 ◽

Vol 66-68 ◽

pp. 1874-1877 ◽

Cited By ~ 1

Author(s):

Ming Lu Zhang ◽

Yi Ren Yang ◽

Zhi Yong Lu ◽

Li Lu

Keyword(s):

Wind Tunnel ◽

Vortex Flow ◽

Vortex Breakdown ◽

Delta Wing ◽

Pressure Fluctuations ◽

Spiral Wave ◽

Leading Edge ◽

Fluid State ◽

Unsteady Characteristics ◽

Leading Edge Vortices

Experiment of unsteady pressure measurement on the surface of wing with 75° sweep delta wing has been carried out in a wind tunnel in order to investigate unsteady characteristics of breakdown vortices over delta wing after the leading edge vortices were breakdown. The result of experiment shows that alter of RMS pressure fluctuations and fluid state of leading edge vortices on the top surface of delta wing are correlative. At the angle region with vortex breakdown, RMS of pressure fluctuations are very huge, similarly buffeting strength of delta wing are large. With increasing angle of attack, alter of buffeting strength is in accordance with RMS pressure fluctuations. Analysis of the pressure signal shows the spiral wave of the breakdown vortex flow over the wing is the primary part of whole RMS pressure fluctuations. Delta wing produces buffeting because of the spiral wave.

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