scholarly journals Strong geographical variation in wing aspect ratio of a damselfly,Calopteryx maculata(Odonata: Zygoptera)

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1219 ◽  
Author(s):  
Christopher Hassall
Keyword(s):  
Aspect Ratio ◽  
Geographical Variation ◽  
Calopteryx Maculata ◽  
Wing Aspect Ratio

scholarly journals Strong longitudinal variation in wing aspect ratio of a damselfly, Calopteryx maculata (Odonata: Zygoptera)

2015 ◽  
Author(s):  
Christopher Hassall
Keyword(s):  
North America ◽  
Aspect Ratio ◽  
Geometric Morphometrics ◽  
Wing Shape ◽  
Functional Ecology ◽  
Long Distance ◽  
Wide Range ◽  
Longitudinal Pattern ◽  
Calopteryx Maculata ◽  
Wing Aspect Ratio

Geographical patterns in body size have been described across a wide range of species, leading to the development of a series of fundamental biological rules. However, shape variables are less well-described despite having substantial consequences for organismal performance. Wing aspect ratio (AR) has been proposed as a key shape parameter that determines function in flying animals, with high AR corresponding to longer, thinner wings that promote high manoeuvrability, low speed flight, and low AR corresponding to shorter, broader wings that promote high efficiency long distance flight. From this principle it might be predicted that populations at range edges would exhibit low AR wings. I test this hypothesis using the riverine damselfly, Calopteryx maculata, sampled from 34 sites across its range margin in North America. Nine hundred and seven male specimens were captured from across the 34 sites (mean=26.7 ±2.9 SE per site), dissected and measured to quantify the area and length of all four wings. Geometric morphometrics were employed to investigate geographical variation in wing shape. The majority of variation in wing shape involved changes in wing aspect ratio, confirmed independently by geometric morphometrics and wing measurements. There was a weak positive relationship between wing aspect ratio and temperature, in line with work on other insects. However, there was a strong longitudinal pattern in which western populations exhibited lower wing aspect ratio. This longitudinal pattern may be related to increasing variability in precipitation from east to west in North America. I discuss my findings in light of research of the functional ecology of wing shape across vertebrate and invertebrate taxa

scholarly journals Strong longitudinal variation in wing aspect ratio of a damselfly, Calopteryx maculata (Odonata: Zygoptera)

2015 ◽  
Author(s):  
Christopher Hassall
Keyword(s):  
North America ◽  
Aspect Ratio ◽  
Geometric Morphometrics ◽  
Wing Shape ◽  
Functional Ecology ◽  
Long Distance ◽  
Wide Range ◽  
Longitudinal Pattern ◽  
Calopteryx Maculata ◽  
Wing Aspect Ratio

Geographical patterns in body size have been described across a wide range of species, leading to the development of a series of fundamental biological rules. However, shape variables are less well-described despite having substantial consequences for organismal performance. Wing aspect ratio (AR) has been proposed as a key shape parameter that determines function in flying animals, with high AR corresponding to longer, thinner wings that promote high manoeuvrability, low speed flight, and low AR corresponding to shorter, broader wings that promote high efficiency long distance flight. From this principle it might be predicted that populations at range edges would exhibit low AR wings. I test this hypothesis using the riverine damselfly, Calopteryx maculata, sampled from 34 sites across its range margin in North America. Nine hundred and seven male specimens were captured from across the 34 sites (mean=26.7 ±2.9 SE per site), dissected and measured to quantify the area and length of all four wings. Geometric morphometrics were employed to investigate geographical variation in wing shape. The majority of variation in wing shape involved changes in wing aspect ratio, confirmed independently by geometric morphometrics and wing measurements. There was a weak positive relationship between wing aspect ratio and temperature, in line with work on other insects. However, there was a strong longitudinal pattern in which western populations exhibited lower wing aspect ratio. This longitudinal pattern may be related to increasing variability in precipitation from east to west in North America. I discuss my findings in light of research of the functional ecology of wing shape across vertebrate and invertebrate taxa

Numerical Study of Winglet at Low Reynolds Numbers

2013 ◽  
Author(s):  
Sina Pooladsanj ◽  
Mehran Tadjfar
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Vortex Flow ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Flow Zone ◽  
Low Reynolds Numbers ◽  
Structured Grid ◽  
Flow Field Characteristics ◽  
Wing Aspect Ratio

A numerical study has been performed to evaluate the aerodynamics coefficients of a winglet in the range of Reynolds numbers below 30,000. In this study some parameters on winglet design have been considered. The effect of winglet-tip airfoil thickness has been investigated on aerodynamics coefficients. In order to explore this effect, two different airfoils (NACA0002 and NACA0012) were employed at the winglet-tip. The influence of varying the winglet connection angle to the wing on aerodynamics coefficients and flow field characteristics in the vortex flow zone such as; circulation magnitude and vorticity magnitude in the vortex core have been studied. Six connection angles including 20°, 30°, 40°, 50°, 60° and 70° have been studied. Negative values of these angles have also been considered. In addition, the effect of changing wing aspect ratio on aerodynamics coefficients has been investigated. To solve the flow field around the studied geometry a fully structured grid was used which consists of 84 blocks.

Latitudinal Variation of Wing: Thorax Size Ratio and Wing-Aspect Ratio in Drosophila melanogaster

Evolution ◽  
1998 ◽  
Vol 52 (5) ◽  
pp. 1353 ◽  
Author(s):  
Ricardo B. R. Azevedo ◽  
Avis C. James ◽  
Jennie McCabe ◽  
L. Partridge
Keyword(s):  
Drosophila Melanogaster ◽  
Aspect Ratio ◽  
Size Ratio ◽  
Latitudinal Variation ◽  
Wing Aspect Ratio

Non-linear aeroelastic response of high aspect-ratio wings in the frequency domain

2017 ◽  
Vol 121 (1240) ◽  
pp. 858-876 ◽  
Author(s):  
F. Afonso ◽  
J. Vale ◽  
É. Oliveira ◽  
F. Lau ◽  
A. Suleman
Keyword(s):  
Aspect Ratio ◽  
Current Trend ◽  
Commercial Aircraft ◽  
Aeroelastic Response ◽  
Flutter Speed ◽  
Wing Model ◽  
Induced Drag ◽  
Non Linear ◽  
Flutter Boundary ◽  
Wing Aspect Ratio

ABSTRACTA current trend in the aeronautic industry is to increase the wing aspect ratio to enhance aerodynamic efficiency by reducing the induced drag and thus reduce fuel consumption. Despite the associated benefits of a large aspect ratio, such as higher lift-to-drag ratios and range, commercial aircraft usually have a relatively low aspect ratio. This is partially explained by the fact that the wing becomes more flexible with increasing aspect ratio and thus more prone to large deflections, which can cause aeroelastic instability problems such as flutter. In this work, an aeroelastic study is conducted on a rectangular wing model of 20 m span and variable chord for a low subsonic speed condition to evaluate the differences between linear and non-linear static aeroelastic responses. Comparisons between linear and non-linear displacements, natural frequencies and flutter boundary are performed. An in-house non-linear aeroelastic framework was employed for this purpose. In this work, the influence of the aspect ratio and geometric non-linearity (highly deformed states) is assessed in terms of aeroelastic performance parameters: flutter speed and divergence speed. A nearly linear correlation of flutter speed difference (relative to linear analysis results) with vertical-tip displacement difference is observed. The flutter and divergence speeds vary substantially as the wing aspect ratio increases, and the divergence speeds always remain above the flutter speed. Furthermore, the flutter mechanism was observed to change as the wing chord is decreased.

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