scholarly journals Morphological diversification has led to inter-specific variation in elastic wing deformation during flight in scarab beetles

2020 ◽  
Vol 7 (4) ◽  
pp. 200277 ◽  
Author(s):  
Y. Meresman ◽  
J. F. Husak ◽  
R. Ben-Shlomo ◽  
G. Ribak
Keyword(s):  
Aerodynamic Force ◽  
Leading Edge ◽  
Dung Beetles ◽  
Food Sources ◽  
Wing Vein ◽  
Geometric Morphometric ◽  
Insect Wing ◽  
Specific Variation ◽  
Wing Deformation ◽  
Scarab Beetles

Insect wing shapes and the internal wing-vein arrangement are remarkably diverse. Although the wings lack intrinsic musculature to adjust shape actively, they elastically deform due to aerodynamic and inertial loads during flapping. In turn, the deformations alter the shape of the wing profile affecting the aerodynamic force. To determine how changes in wing-vein arrangement affect elastic wing deformation during free flight, we compared elastic wing deformations between free-flying rose chafers ( Protaetia cuprea ) and dung beetles ( Scarabaeus puncticollis ), complementing the comparison with wing static bending measurements. The broader relevance of the results to scarab beetle divergence was examined in a geometric morphometric (GM) analysis of wing-vein arrangement in 20 species differing in phylogeny and ecology. Despite rose chafers and dung beetles demonstrating similar flapping kinematics and wing size, the rose chafer wings undergo greater elastic deformation during flapping. GM analyses corrected for phylogenetic relatedness revealed that the two beetles represent extremes in wing morphology among the scarab subfamilies. Most of the differences occur at the distal leading edge and the proximal trailing edge of the wing, diversifying the flexibility of these regions, thereby changing the pattern of elastic wing deformation during flapping. Changes to local wing compliance seem to be associated with the diversification of scarab beetles to different food sources, perhaps as an adaptation to meet the demands of diverse flight styles.

Relationship between aerodynamic forces, flow structures and wing camber for rotating insect wing planforms

2013 ◽  
Vol 730 ◽  
pp. 52-75 ◽  
Author(s):  
R. R. Harbig ◽  
J. Sheridan ◽  
M. C. Thompson
Keyword(s):  
Leading Edge ◽  
Fruit Fly ◽  
Reynolds Numbers ◽  
Flow Structures ◽  
Aerodynamic Forces ◽  
Insect Wing ◽  
Deformation Parameters ◽  
Edge Vortex ◽  
Wing Deformation ◽  
Rigid Wing

AbstractWing deformation is observed during the flight of some insect species; however, the effect of these distorted wing shapes on the leading edge vortex (LEV) is not well understood. In this study, we investigate the effect of one of these deformation parameters, (rigid) wing camber, on the flow structures and aerodynamic forces for insect-like wings, using a numerical model of an altered fruit fly wing revolving at a constant angular velocity. Both positive and negative camber was investigated at Reynolds numbers of 120 and 1500, along with the chordwise location of maximum camber. It was found that negatively cambered wings produce very similar LEV structures to non-cambered wings at both Reynolds numbers, but high positive camber resulted in the formation of multiple streamwise vortices at the higher Reynolds number, which disrupt the development of the main LEV. Despite this, positively cambered wings were found to produce higher lift to drag ratios than flat or negatively cambered wings. It was determined that a region of low pressure near the wing’s leading edge, combined with the curvature of the wing’s upper surface in this region, resulted in a vertical tilting of the net force vector for positively cambered wings, which explains how insects can benefit from wing camber.

scholarly journals Numerical simulation of flapping airfoil with alula

2020 ◽  
Vol 12 ◽  
pp. 175682932097798
Author(s):  
Han Bao ◽  
Wenqing Yang ◽  
Dongfu Ma ◽  
Wenping Song ◽  
Bifeng Song
Keyword(s):  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Geometric Parameters ◽  
Flight Performance ◽  
Relative Angle ◽  
Vertical Distance ◽  
Unsteady Effect ◽  
Flapping Airfoil

Bionic micro aerial vehicles have become popular because of their high thrust efficiency and deceptive appearances. Leading edge or trailing edge devices (such as slots or flaps) are often used to improve the flight performance. Birds in nature also have leading-edge devices, known as the alula that can improve their flight performance at large angles of attack. In the present study, the aerodynamic performance of a flapping airfoil with alula is numerically simulated to illustrate the effects of different alula geometric parameters. Different alula relative angles of attack β (the angle between the chord line of the alula and that of the main airfoil) and vertical distances h between the alula and the main airfoil are simulated at pre-stall and post-stall conditions. Results show that at pre-stall condition, the lift increases with the relative angle of attack and the vertical distance, but the aerodynamic performance is degraded in the presence of alula compared with no alula, whereas at post-stall condition, the alula greatly enhances the lift. However, there seems to be an optimal relative angle of attack for the maximum lift enhancement at a fixed vertical distance considering the unsteady effect, which may indicate birds can adjust the alula twisting at different spanwise positions to achieve the best flight performance. Different alula geometric parameters may affect the aerodynamic force by modifying the pressure distribution along the airfoil. The results are instructive for design of flapping-wing bionic unmanned air vehicles.

scholarly journals The Geometry and Mechanics of Insect Wing Deformations in Flight: A Modelling Approach

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 446
Author(s):  
Robin Wootton
Keyword(s):  
Remote Control ◽  
Deformation Process ◽  
High Speed ◽  
Physical Models ◽  
Insect Wing ◽  
Stable Conditions ◽  
Torsional Component ◽  
Wing Deformation ◽  
Shaped Section ◽  
Modelling Approach

The nature, occurrence, morphological basis and functions of insect wing deformation in flight are reviewed. The importance of relief in supporting the wing is stressed, and three types are recognized, namely corrugation, an M-shaped section and camber, all of which need to be overcome if wings are to bend usefully in the morphological upstroke. How this is achieved, and how bending, torsion and change in profile are mechanically interrelated, are explored by means of simple physical models which reflect situations that are visible in high speed photographs and films. The shapes of lines of transverse flexion are shown to reflect the timing and roles of bending, and their orientation is shown to determine the extent of the torsional component of the deformation process. Some configurations prove to allow two stable conditions, others to be monostable. The possibility of active remote control of wing rigidity by the thoracic musculature is considered, but the extent of this remains uncertain.

Sting-free measurements on a magnetically supported right circular cylinder aligned with the free stream

2008 ◽  
Vol 596 ◽  
pp. 49-72 ◽  
Author(s):  
HIROSHI HIGUCHI ◽  
HIDEO SAWADA ◽  
HIROYUKI KATO
Keyword(s):  
Circular Cylinder ◽  
Shear Layer ◽  
Free Stream ◽  
Aerodynamic Force ◽  
Cross Flow ◽  
Leading Edge ◽  
Magnetic Suspension ◽  
Recirculation Region ◽  
Mean Velocity ◽  
Wide Range

The flow over cylinders of varying fineness ratio (length to diameter) aligned with the free stream was examined using a magnetic suspension and balance system in order to avoid model support interference. The drag coefficient variation of a right circular cylinder was obtained for a wide range of fineness ratios. Particle image velocimetry (PIV) was used to examine the flow field, particularly the behaviour of the leading-edge separation shear layer and its effect on the wake. Reynolds numbers based on the cylinder diameter ranged from 5×104 to 1.1×105, while the major portion of the experiment was conducted at ReD=1.0×105. For moderately large fineness ratio, the shear layer reattaches with subsequent growth of the boundary layer, whereas over shorter cylinders, the shear layer remains detached. Differences in the wake recirculation region and the immediate wake patterns are clarified in terms of both the mean velocity and turbulent flow fields, including longitudinal vortical structures in the cross-flow plane of the wake. The minimum drag corresponded to the fineness ratio for which the separated shear layer reattached at the trailing edge of the cylinder. The base pressure was obtained with a telemetry technique. Pressure fields and aerodynamic force fluctuations are also discussed.

scholarly journals Schlieren photography on freely flying hawkmoth

2018 ◽  
Vol 14 (5) ◽  
pp. 20180198 ◽  
Author(s):  
Yun Liu ◽  
Jesse Roll ◽  
Stephen Van Kooten ◽  
Xinyan Deng
Keyword(s):  
Aerodynamic Force ◽  
Leading Edge ◽  
Vortical Flow ◽  
Natural Setting ◽  
Optical Flow Method ◽  
Flying Insects ◽  
Flow Features ◽  
Potential Applications ◽  
Edge Vortex ◽  
Schlieren Photography

The aerodynamic force on flying insects results from the vortical flow structures that vary both spatially and temporally throughout flight. Due to these complexities and the inherent difficulties in studying flying insects in a natural setting, a complete picture of the vortical flow has been difficult to obtain experimentally. In this paper, Schlieren , a widely used technique for highspeed flow visualization, was adapted to capture the vortex structures around freely flying hawkmoth ( Manduca ). Flow features such as leading-edge vortex, trailing-edge vortex, as well as the full vortex system in the wake were visualized directly. Quantification of the flow from the Schlieren images was then obtained by applying a physics-based optical flow method, extending the potential applications of the method to further studies of flying insects.

scholarly journals Insect wing deformation measurements using high speed digital holographic interferometry

2010 ◽  
Vol 18 (6) ◽  
pp. 5661 ◽  
Author(s):  
Daniel D. Aguayo ◽  
Fernando Mendoza Santoyo ◽  
Manuel H. De la Torre-I ◽  
Manuel D. Salas-Araiza ◽  
Cristian Caloca-Mendez ◽  
...  
Keyword(s):  
Holographic Interferometry ◽  
High Speed ◽  
Insect Wing ◽  
Wing Deformation ◽  
Deformation Measurements

scholarly journals Reconstructing Full-Field Flapping Wing Dynamics from Sparse Measurements

2020 ◽  
Author(s):  
William Johns ◽  
Lisa Davis ◽  
Mark Jankauski
Keyword(s):  
Aerodynamic Force ◽  
Force Production ◽  
Energetic Efficiency ◽  
Reconstruction Technique ◽  
Reconstruction Method ◽  
Full Field ◽  
Insect Wing ◽  
Insect Wings ◽  
Flying Insects ◽  
Sparse Measurements

AbstractFlapping insect wings deform during flight. This deformation benefits the insect’s aerodynamic force production as well as energetic efficiency. However, it is challenging to measure wing displacement field in flying insects. Many points must be tracked over the wing’s surface to resolve its instantaneous shape. To reduce the number of points one is required to track, we propose a physics-based reconstruction method called System Equivalent Reduction Expansion Processes (SEREP) to estimate wing deformation and strain from sparse measurements. Measurement locations are determined using a Weighted Normalized Modal Displacement (NMD) method. We experimentally validate the reconstruction technique by flapping a paper wing from 5-9 Hz with 45° and measuring strain at three locations. Two measurements are used for the reconstruction and the third for validation. Strain reconstructions had a maximal error of 30% in amplitude. We extend this methodology to a more realistic insect wing through numerical simulation. We show that wing displacement can be estimated from sparse displacement or strain measurements, and that additional sensors spatially average measurement noise to improve reconstruction accuracy. This research helps overcome some of the challenges of measuring full-field dynamics in flying insects and provides a framework for strain-based sensing in insect-inspired flapping robots.

scholarly journals Effect of Wing Corrugation on the Aerodynamic Efficiency of Two-Dimensional Flapping Wings

2020 ◽  
Vol 10 (20) ◽  
pp. 7375
Author(s):  
Thanh Tien Dao ◽  
Thi Kim Loan Au ◽  
Soo Hyung Park ◽  
Hoon Cheol Park
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Two Dimensional ◽  
Aerodynamic Efficiency ◽  
Insect Wing ◽  
Wing Motion ◽  
Computational Fluid Dynamics Cfd

Many previous studies have shown that wing corrugation of an insect wing is only structurally beneficial in enhancing the wing’s bending stiffness and does not much help to improve the aerodynamic performance of flapping wings. This study uses two-dimensional computational fluid dynamics (CFD) in aiming to identify a proper wing corrugation that can enhance the aerodynamic performance of the KUBeetle, an insect-like flapping-wing micro air vehicle (MAV), which operates at a Reynolds number of less than 13,000. For this purpose, various two-dimensional corrugated wings were numerically investigated. The two-dimensional flapping wing motion was extracted from the measured three-dimensional wing kinematics of the KUBeetle at spanwise locations of r = (0.375 and 0.75)R. The CFD analysis showed that at both spanwise locations, the corrugations placed over the entire wing were not beneficial for improving aerodynamic efficiency. However, for the two-dimensional flapping wing at the spanwise location of r = 0.375R, where the wing experiences relatively high angles of attack, three specially designed wings with leading-edge corrugation showed higher aerodynamic performance than that of the non-corrugated smooth wing. The improvement is closely related to the flow patterns formed around the wings. Therefore, the proposed leading-edge corrugation is suggested for the inboard wing of the KUBeetle to enhance aerodynamic performance. The corrugation in the inboard wing may also be structurally beneficial.

scholarly journals Insights into the molecular mechanisms underlying diversified wing venation among insects

2014 ◽  
Vol 281 (1789) ◽  
pp. 20140264 ◽  
Author(s):  
Osamu Shimmi ◽  
Shinya Matsuda ◽  
Masatsugu Hatakeyama
Keyword(s):  
Molecular Mechanisms ◽  
Positional Information ◽  
Wing Venation ◽  
Wing Vein ◽  
Insect Wing ◽  
Vein Formation ◽  
Key Factor ◽  
Characteristic Features ◽  
Species Specific ◽  
Directional Transport

Insect wings are great resources for studying morphological diversities in nature as well as in fossil records. Among them, variation in wing venation is one of the most characteristic features of insect species. Venation is therefore, undeniably a key factor of species-specific functional traits of the wings; however, the mechanism underlying wing vein formation among insects largely remains unexplored. Our knowledge of the genetic basis of wing development is solely restricted to Drosophila melanogaster . A critical step in wing vein development in Drosophila is the activation of the decapentaplegic (Dpp)/bone morphogenetic protein (BMP) signalling pathway during pupal stages. A key mechanism is the directional transport of Dpp from the longitudinal veins into the posterior crossvein by BMP-binding proteins, resulting in redistribution of Dpp that reflects wing vein patterns. Recent works on the sawfly Athalia rosae , of the order Hymenoptera, also suggested that the Dpp transport system is required to specify fore- and hindwing vein patterns. Given that Dpp redistribution via transport is likely to be a key mechanism for establishing wing vein patterns, this raises the interesting possibility that distinct wing vein patterns are generated, based on where Dpp is transported. Experimental evidence in Drosophila suggests that the direction of Dpp transport is regulated by prepatterned positional information. These observations lead to the postulation that Dpp generates diversified insect wing vein patterns through species-specific positional information of its directional transport. Extension of these observations in some winged insects will provide further insights into the mechanisms underlying diversified wing venation among insects.

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