Effect of Winglet Serration Geometry on the Wingtip Vortex

Scaling Analysis on the Dynamic and Instability Characteristics of Isolated Wingtip Vortex

AIAA Journal ◽

10.2514/1.j060281 ◽

2021 ◽

pp. 1-13

Author(s):

Yang Xiang ◽

Ze-Peng Cheng ◽

Yi-Ming Wu ◽

Hong Liu ◽

Fuxin Wang

Keyword(s):

Scaling Analysis ◽

Wingtip Vortex

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Experimental investigation on the structures and induced drag of wingtip vortices for different wingtip configurations

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

10.1177/0954410020947911 ◽

2020 ◽

pp. 095441002094791

Author(s):

Ze-Peng Cheng ◽

Yang Xiang ◽

Hong Liu

Keyword(s):

Growth Rate ◽

Form Factor ◽

Drag Coefficient ◽

Particle Image ◽

Vortex Center ◽

Streamwise Location ◽

Induced Drag ◽

Wingtip Vortex ◽

Image Velocimetry ◽

Drag And Lift

As an effective method to reduce induced drag and the risk of wake encounter, the winglet has been an essential device and developed into diverse configurations. However, the structures and induced drag, as well as wandering features of the wingtip vortices ( WTVs) generated by these diverse winglet configurations are not well understood. Thus, the WTVs generated by four typical wingtip configurations, namely the rectangular wing with blended/raked/split winglet and without winglet (Model BL/ RA/ SP/NO for short), are investigated in this paper using particle image velocimetry technology. Comparing with an isolated primary wingtip vortex generated by Model NO, multiple vortices are twisted coherently after installing the winglets. In addition, the circulation evolution of WTVs demonstrates that the circulation for Model SP is the largest, while Model RA is the smallest. By tracking the instantaneous vortex center, the vortex wandering behavior is observed. The growth rate of wandering amplitude along with the streamwise location from the quickest to the slowest corresponds to Model SP, Model NO, Model BL, Model RA in sequence, implying that the WTVs generated by model SP exhibit the quickest mitigation. Considering that the induced drag scales as the lift to power 2, the induced drag and lift are estimated based on the wake integration method, and then the form factor λ, defined by [Formula: see text], is calculated to evaluate the aerodynamic performance. Comparing with the result of Model NO, the form factor decreases by 7.99%, 4.80%, and 2.60% for Model RA, Model BL, Model SP, respectively. In sum, Model RA and BL have a smaller induced drag coefficient but decay slower; while Model SP has a larger induced drag coefficient but decays quicker. An important implication of these results is that reducing the strength of WTVs and increasing the growth rate of vortex wandering amplitude can be the mutual requirements for designing new winglets.

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A Reynolds Stress Relaxation Turbulence Model Applied to A Wingtip Vortex Flow

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition ◽

10.2514/6.2011-663 ◽

2011 ◽

Cited By ~ 3

Author(s):

Matthew Churchfield ◽

Gregory Blaisdell

Keyword(s):

Stress Relaxation ◽

Reynolds Stress ◽

Turbulence Model ◽

Vortex Flow ◽

Wingtip Vortex

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Wingtip Vortex Turbine Investigation for Vortex Energy Recovery

10.4271/901936 ◽

1990 ◽

Cited By ~ 1

Author(s):

William K. Abeyounis ◽

James C. Patterson ◽

H. Paul Stough ◽

Alfred J. Wunschel ◽

Patrick D. Curran

Keyword(s):

Energy Recovery ◽

Wingtip Vortex

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Passive Wingtip Vortex Control by Using Tip-Mounted Half Delta Wings in Ground Effect

Journal of Fluids Engineering ◽

10.1115/1.4044669 ◽

2019 ◽

Vol 142 (2) ◽

Author(s):

Anan Lu ◽

Tim Lee

Keyword(s):

Vortex Flow ◽

Ground Effect ◽

Tip Vortex ◽

Secondary Vortex ◽

Flow Properties ◽

Delta Wings ◽

Vortex Control ◽

Physical Mechanisms ◽

Induced Drag ◽

Wingtip Vortex

Abstract The ground effect on the wingtip vortex generated by a rectangular semiwing equipped with tip-mounted regular and reverse half delta wings was investigated experimentally. The passive tip vortex control always led to a reduced lift-induced drag as the ground was approached. In close ground proximity, the presence of the corotating ground vortex (GV) added vorticity to the tip vortex while the counter-rotating secondary vortex (SV) negated its vorticity level. The interaction of the GV and SV with the tip vortex and their impact on the lift-induced drag were discussed. Physical mechanisms responsible for the change in the vortex flow properties in ground effect were also provided.

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