Application of Image Preprocessing on PIV Experimental Study of Wake Vortex Interactive Instability

A basic experiment study with a simplified wing model was carried out to introduce a opposite wake vortex by different sizes of spoilers. A PIV measurement was employed to obtain a two dimension wing wake vortex velocity field data of different spoilers in a water towing tank and confirm the existence of Reyleigh-Ludwieg instability in aircraft wake vortex. The image preprocessing is useful in PIV post-processing by comparing the three kinds of image preprocessing results with normal PIV image processing results.

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Wake Vortex Control Using Modified Flaps

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.365-366.827 ◽

2013 ◽

Vol 365-366 ◽

pp. 827-834

Author(s):

Yi He ◽

Jin Wen Yang ◽

Feng Bao

Keyword(s):

Experimental Investigation ◽

Research Work ◽

Experimental Results ◽

Wake Vortex ◽

Towing Tank ◽

Labor Conditions ◽

Vortex Control ◽

Piv Measurement ◽

Aircraft Wake

The present paper is on the experimental investigation of a potentially effective method to alleviate the strength of aircraft wake vortex. The research work was carried out in a water-towing tank which equipped with a 2-D PIV system. By using modified flaps attached to the baseline-airfoil, the Rayleigh-Ludwieg instability of the wake vortex was activated, resulting in a premature dissipation of the wake vortex. The experimental results of PIV measurement exhibited that the circulation of the wake vortex was reduced to over 50% for the optimal case at 45 wingspans downstream with suitable settings, which proved the effectiveness of the modified-flap treatment in alleviating the wake vortex under labor conditions.

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The Instability of a Four-Vortex Wake System in a Water Towing Tank

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.756-759.1484 ◽

2013 ◽

Vol 756-759 ◽

pp. 1484-1488

Author(s):

Yi He ◽

Jin Wen Yang ◽

Feng Bao

Keyword(s):

Interaction Process ◽

Wake Vortex ◽

Vortex Wake ◽

Towing Tank ◽

Piv Measurement

A simplified rectangular baseline-airfoil model attached with tailored flaps was designed to study the Rayleigh-Ludwieg instability by tailoring a four-vortex wake system. By means of PIV measurement in a water towing tank, the interaction process and circulation evolution of the wake system were obtained systematically. The circulation remains was reduced to ca. 40% after 43 wingspans which proved the application potentials of this method in alleviating the wake vortex.

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Study on the influence of linear and nonlinear distribution of crosswind on the motion of aircraft wake vortex

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410020987430 ◽

2021 ◽

pp. 095441002098743

Author(s):

Dong Li ◽

Ziming Xu ◽

Ke Zhang ◽

Zeyu Zhang ◽

Jinxin Zhou ◽

...

Keyword(s):

Numerical Simulations ◽

Dissipation Rate ◽

Vortex Pair ◽

Vertical Shear ◽

Wake Vortex ◽

Analysis Method ◽

Velocity Magnitude ◽

Aircraft Wake ◽

Linear And Nonlinear ◽

Nonlinear Distribution

Environmental crosswind can greatly affect the development of aircraft wake vortex pair. Previous numerical simulations and experiments have shown that the nonlinear vertical shear of the crosswind velocity can affect the dissipation rate of the aircraft wake vortex, causing each vortex of the vortex pair descent with different velocity magnitude, which will lead to the asymmetrical settlement and tilt of the wake vortex pair. Through numerical simulations, this article finds that uniform crosswind convection and linear vertical shear crosswind convection can also have an effect on the strength of the vortex. This effect is inversely proportional to the cube of the vortex spacing, so it is more intense on small separation vortex pair. In addition, the superposition of crosswind and vortex-induced velocities will lead to the asymmetrical pressure distribution around the vortex pair, which will also cause the tilt of the vortex pair. Furthermore, a new analysis method for wake vortex is proposed, which can be used to predict the vortex trajectory.

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Analysis of Predicted Aircraft Wake Vortex Transport and Comparison with Experiment

Journal of Aircraft ◽

10.2514/3.59843 ◽

1975 ◽

Vol 12 (7) ◽

pp. 619-620

Author(s):

M. R. Brashears ◽

James N. Hallock

Keyword(s):

Wake Vortex ◽

Comparison With Experiment ◽

Aircraft Wake

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Modeling the Radar Signature of Raindrops in Aircraft Wake Vortices

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-11-00220.1 ◽

2013 ◽

Vol 30 (3) ◽

pp. 470-484 ◽

Cited By ~ 7

Author(s):

Zhongxun Liu ◽

Nicolas Jeannin ◽

Francois Vincent ◽

Xuesong Wang

Keyword(s):

Traffic Control ◽

Vortex Flow ◽

Doppler Radar ◽

Elevation Angle ◽

Wake Vortex ◽

Wake Vortices ◽

Radar Signature ◽

Radar Echo ◽

Aircraft Wake ◽

Resolution Cell

Abstract The present work is dedicated to the modeling and simulation of the radar signature of raindrops within wake vortices. This is achieved through the computation of the equation of raindrop motion within the wake vortex flow. Based on the inhomogeneous distribution of raindrops within wake vortices, the radar echo model is computed for raindrops in a given resolution cell. Simulated Doppler radar signatures of raindrops within wake vortices are shown to be a potential criterion for identifying wake vortex hazards in air traffic control. The dependence of the radar signature on various parameters, including the radial resolution and antenna elevation angle, is also analyzed.

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Recognition of Aircraft Wake Vortex Based on Random Forest

IEEE Access ◽

10.1109/access.2022.3141595 ◽

2022 ◽

pp. 1-1

Author(s):

Weijun Pan ◽

Haoran Yin ◽

Yuanfei Leng ◽

Xiaolei Zhang

Keyword(s):

Random Forest ◽

Wake Vortex ◽

Aircraft Wake

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Identification of Aircraft Wake Vortex Based on SVM

Mathematical Problems in Engineering ◽

10.1155/2020/9314164 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Weijun Pan ◽

Zhengyuan Wu ◽

Xiaolei Zhang

Keyword(s):

Environmental Parameters ◽

Classification Model ◽

Support Vector ◽

Wake Vortex ◽

Doppler Lidar ◽

Pulsed Doppler ◽

Wind Fields ◽

Wake Turbulence ◽

Aircraft Wake ◽

Separation Standards

The aircraft wake vortex has important influence on the operation of the airspace utilization ratio. Particularly, the identification of aircraft wake vortex using the pulsed Doppler lidar characteristics provides a new knowledge of wake turbulence separation standards. This paper develops an efficient pattern recognition-based method for identifying the aircraft wake vortex measured with the pulsed Doppler lidar. The proposed method is outlined in two stages. (i) First, a classification model based on support vector machine (SVM) is introduced to extract the radial velocity features in the wind fields by combining the environmental parameters. (ii) Then, grid search and cross-validation based on soft margin SVM with kernel tricks are employed to identify the aircraft wake vortex, using the test dataset. The dataset includes wake vortices of various aircrafts collected at the Chengdu Shuangliu International Airport from Aug 16, 2018, to Oct 10, 2018. The experimental results on dataset show that the proposed method can identify the aircraft wake vortex with only a small loss, which ensures the satisfactory robustness in detection performance.

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