Leading-Edge Vortices Elevate Lift of Autorotating Plant Seeds

  title={Leading-Edge Vortices Elevate Lift of Autorotating Plant Seeds},
  author={David Lentink and William B. Dickson and Johan L. van Leeuwen and Michael H. Dickinson},
  pages={1438 - 1440}
Helicopter Seed Lift The “helicopter” seeds of maple trees and other similar autorotating seeds detach from their parent tree under windy conditions and gyrate as they are dispersed by the wind. The reproductive success of the tree depends on the flight performance of its seeds. Autorotating seeds are known to generate high lift as they slowly descend through the air, but the means by which they do so is unclear. Lentink et al. (p. 1438, see the cover) have elucidated the aerodynamic mechanism… 

Petiolate wings: effects on the leading-edge vortex in flapping flight

For more petiolate wings the LEV is generally larger, stronger in circulation, and covers a greater area of the wing surface, particularly at the mid-span and inboard locations early in the wing stroke cycle.

Aerodynamic Features of Maple Seeds in the Autorotative Flight

The autorotative flight of maple seeds(Acer palmatum) is numerically simulated based on the 3D geometry and the motion parameters of real seeds. The nominal values of the motion parameters are 1.26

Forewings match the formation of leading-edge vortices and dominate aerodynamic force production in revolving insect wings

The results indicate that the size and strength of the LEVs can be well quantified with introduction of a conical LEV angle, which varies remarkably with angles of attack and Reynolds numbers but within the forewing region while showing less sensitivity to the wing morphologies.

Curving to Fly: Synthetic Adaptation Unveils Optimal Flight Performance of Whirling Fruits.

Both hydrodynamic theory and experiments involving synthetic, double-winged fruits show that to produce a maximal flight time there is an optimal fold angle for the desiccated sepals, highlighting that wing curvature can aid as an efficient mechanism for wind dispersal of seeds and may improve the fitness of their producers in the context of an ecological strategy.

Aerodynamics and Flight Dynamics of Free-Falling Ash Seeds

Samaras or winged seeds spread themselves by wind. Ash seed, unlike other samaras, has a high aspect ratio wing which can generate enough lift force to slow down descent by rotating about the

A separated vortex ring underlies the flight of the dandelion

The discovery of the separated vortex ring provides evidence of the existence of a new class of fluid behaviour around fluid-immersed bodies that may underlie locomotion, weight reduction and particle retention in biological and manmade structures.

Effect of initial attitude on autorotation flight of maple samaras (Acer palmatum)

Many samaras or winged seeds such as maple seeds make an autorotational flight during their falling. Slow descent speed of autorotating maple seeds has been known to be caused by the high lift

Mechanism of autorotation flight of maple samaras (Acer palmatum)

Some winged seeds exhibit autorotation flight during their descent to migrate far away from their parent trees by using oncoming wind. The reduced descent speed of autorotating maple seeds is

Mechanism of autorotation flight of maple samaras (Acer palmatum)

Some winged seeds exhibit autorotation flight during their descent to migrate far away from their parent trees by using oncoming wind. The reduced descent speed of autorotating maple seeds is

On the autorotation of animal wings

It is reported here that isolated wings from Anna's hummingbirds, and also from 10 species of insects, can stably autorotate and achieve descent speeds and aerodynamic performance comparable to those of samaras.



Spanwise flow and the attachment of the leading-edge vortex on insect wings

It is reported that, at the Reynolds numbers matching the flows relevant for most insects, flapping wings do not generate a spiral vortex akin to that produced by delta-wing aircraft, and it is found that limiting spanwise flow with fences and edge baffles does not cause detachment of the leading-edge vortex.

Leading-Edge Vortex Lifts Swifts

It is suggested that the flow around the arm-wings of most birds can remain conventionally attached, whereas the swept-back hand-wings generate lift with leading-edge vortices.

Leading-Edge Vortex Improves Lift in Slow-Flying Bats

Using digital particle image velocimetry, it is shown that a small nectar-feeding bat is able to increase lift by as much as 40% using attached leading-edge vortices during slow forward flight, resulting in a maximum lift coefficient of 4.8.

The aerodynamics of revolving wings I. Model hawkmoth wings.

This study uses propeller models to investigate further the forces acting on model hawkmoth wings in 'propeller-like' rotation ('revolution'), and finds force coefficients are remarkably unaffected by considerable variations in leading-edge detail, twist and camber.

Various flying modes of wind-dispersal seeds.

Force production and flow structure of the leading edge vortex on flapping wings at high and low Reynolds numbers

The results suggest that the transport of vorticity from the leading edge to the wake that permits prolonged vortex attachment takes different forms at different Re, analogous to the flow structure generated by delta wing aircraft.

Experiments on the Weis-Fogh mechanism of lift generation by insects in hovering flight. Part 1. Dynamics of the ‘fling’

From a series of experiments using simplified mechanical models we suggest certain minor modifications to the Weis-Fogh (1973)–Lighthill (1973) explanation of the so-called ‘clap and fling’ mechanism


A samara is a winged fruit or seed that autorotates when falling, thereby reducing the sinking speed of the diaspore and increasing the distance it may be transported by winds and formulae for calculation of performance data are given.

Dual leading-edge vortices on flapping wings

An experimental investigation confirmed for the first time the existence of the dual leading-edge vortices observed on flapping wings and the sectional flow structure resembles the dual-vortex observed on non-slender delta wings.