Effects of Leading-Edge Radius on Aerodynamic Characteristics of 50º Delta Wings

Verhaagen, N.G.

doi:10.2514/6.2010-323

Cited by 7 publications

(3 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Over the past 70 years, the phenomenon of stationary LEVs on low aspect ratio (AR) wings has been studied extensively through analytical efforts [4,7,8], experiments [4,9,10] and numerical simulations [11–13]. The most notable example of this type of wing is a delta wing, where LEV formation has been extensively studied in a variety of different settings.…”

Section: Introductionmentioning

confidence: 99%

Leading-edge vortices over swept-back wings with varying sweep geometries

et al. 2019

View full text Add to dashboard Cite

Micro air vehicles are used in a myriad of applications, such as transportation and surveying. Their performance can be improved through the study of wing designs and lift generation techniques including leading-edge vortices (LEVs). Observation of natural fliers, e.g. birds and bats, has shown that LEVs are a major contributor to lift during flapping flight, and the common swift ( Apus apus ) has been observed to generate LEVs during gliding flight. We hypothesize that nonlinear swept-back wings generate a vortex in the leading-edge region, which can augment the lift in a similar manner to linear swept-back wings (i.e. delta wing) during gliding flight. Particle image velocimetry experiments were performed in a water flume to compare flow over two wing geometries: one with a nonlinear sweep (swift-like wing) and one with a linear sweep (delta wing). Experiments were performed at three spanwise planes and three angles of attack at a chord-based Reynolds number of 26 000. Streamlines, vorticity, swirling strength, and Q -criterion were used to identify LEVs. The results show similar LEV characteristics for delta and swift-like wing geometries. These similarities suggest that sweep geometries other than a linear sweep (i.e. delta wing) are capable of creating LEVs during gliding flight.

show abstract

Section: Introductionmentioning

confidence: 99%

Leading-edge vortices over swept-back wings with varying sweep geometries

et al. 2019

View full text Add to dashboard Cite

show abstract

“…LEVs are generated when flow separation occurs at the leading-edge region and forms a shear layer that rolls up to generate a vortex structure over the surface [4,5]; a process that commonly occurs at high angles of attack. Various experimental observations over slender delta wings have shown that these vortical structures can preserve their size and magnitude, thus becoming stationary LEVs for a wide range of flow conditions that offer significant lift enhancement [6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

The leading-edge vortex over a swift-like high-aspect-ratio wing with nonlinear swept-back geometry

Ben-Gida¹,

Gurka²

2022

Bioinspir. Biomim.

View full text Add to dashboard Cite

The leading-edge vortex (LEV) is a common flow structure that forms over wings at high angles of attack. Over the years, LEVs were exploited for augmenting the lift of man-made slender delta wings aircraft. However, recent observations suggested that natural flyers with high-aspect-ratio (high-AR) wings, such as the common swift (Apus apus), can also generate LEVs while gliding. We hypothesize that the planform shape and nonlinear sweep (increasing towards the wingtip) enable the formation and control of such LEVs. In this paper, we investigate whether a stationary LEV can form over a nonlinear swept-back high-AR wing inspired by the swift's wing shape and evaluate its characteristics and potential aerodynamic benefit. Particle image velocimetry (PIV) measurements were performed in a water flume on a high-AR swept-back wing inspired by the swift wing. Experiments were performed at four spanwise sections and a range of angles of attack for a chord-based Reynolds number of 20,000. Stationary LEV structures were identified across the wingspan by utilizing the proper orthogonal decomposition (POD) method for angles of attack of 5-15 degrees. The size and circulation of the stationary LEV were found to grow towards the wingtip in a nonlinear manner due to shear layer feeding and spanwise transport of mass and vorticity within the LEV, thus confirming that nonlinear high-AR swept-back wings can generate stationary LEVs. Our results suggest that the common swift can generate stationary LEVs over its swept-back wings to glide slower and at a higher rate of descent, with the LEVs potentially supporting up to 60% of its weight.

show abstract

“…Because less suction is needed to reattach the separated shear layer on a thick wing, the leading-edge vortex has less strength than above a planar surface. Verhaagen investigated how the leading-edge radius variation (r le /c r ≤ 0.03) influences the vortex system and the aerodynamic characteristics of a 50 • swept delta wing [12]. He reported a decreasing distance of the vortex towards the wing's surface and the leading edge with increasing leading-edge radius.…”

Section: Introductionmentioning

confidence: 99%

Leading-Edge Roughness Affecting Diamond-Wing Aerodynamic Characteristics

et al. 2018

View full text Add to dashboard Cite

Diamond wing configurations for low signature vehicles have been studied in recent years. Yet, despite numerous research on highly swept, sharp edged wings, little research on aerodynamics of semi-slender wings with blunt leading-edges exists. This paper reports on the stall characteristics of the AVT-183 diamond wing configuration with variation of leading-edge roughness size and Reynolds number. Wind tunnel testing applying force and surface pressure measurements are conducted and the results presented and analysed. For the investigated Reynolds number range of 2.1 × 10 6 ≤ R e ≤ 2.7 × 10 6 there is no significant influence on the aerodynamic coefficients. However, leading-edge roughness height influences the vortex separation location. Trip dots produced the most downstream located vortex separation onset. Increasing the roughness size shifts the separation onset upstream. Prior to stall, global aerodynamic coefficients are little influenced by leading-edge roughness. In contrast, maximum lift and maximum angle of attack is reduced with increasing disturbance height. Surface pressure fluctuations show dominant broadband frequency peaks, distinctive for moderate sweep vortex breakdown. The experimental work presented here provides insights into the aerodynamic characteristics of diamond wings in a wide parameter space including a relevant angle of attack range up to post-stall.

show abstract

Effects of Leading-Edge Radius on Aerodynamic Characteristics of 50º Delta Wings

Cited by 7 publications

References 16 publications

Leading-edge vortices over swept-back wings with varying sweep geometries

Leading-edge vortices over swept-back wings with varying sweep geometries

The leading-edge vortex over a swift-like high-aspect-ratio wing with nonlinear swept-back geometry

Leading-Edge Roughness Affecting Diamond-Wing Aerodynamic Characteristics

Contact Info

Product

Resources

About