Small Wing Research Articles

Adaptation to different temperatures results in wing size divergence of the invading species Drosophila nasuta (Diptera: Drosophilidae) in Brazil.

Invasive species threaten biodiversity on a global scale. The success of invasions depends on the species' adaptation to the different environmental conditions of new territories. Studies show that invasive insects present evolutionary changes in wing morphology in areas they are introduced to in response to abiotic conditions. In the last decade, the Asian Drosophila nasuta fly invaded and spread widely throughout Brazil. This insect has preferences for conserved environments and is related to the likely reduction in the abundance of native drosophilids in the Atlantic Forest. Ecological niche modelling analyses showed that rainfall and temperature are the main factors which delimit the geographic distribution of this species. Herein, we verified the existence of significant differences in the wing sizes of D. nasuta in Brazil and evaluated the influence of abiotic factors (rainfall and temperature) on the observed patterns. We conducted 11 measurements on the right-side wings of 240 D. nasuta males collected in the Amazon Forest, Caatinga, Cerrado and Atlantic Forest. Statistical analyses revealed the existence of two groups: one with larger wings, which brought together samples from locations with the lowest temperatures; and one with smaller wings, which corresponded to places with a hotter climate. One explanation for this result is the fact that large wings favour greater heat capture by flies in colder climates, increasing their survival chances in these environments. These rapid evolutionary changes in D. nasuta in this first decade of invasion in Brazil reveal the enormous adaptive potential of this species in this megadiverse country.

The working principles of canard wings and its aerodynamic advantages and effects on aircraft

Canard wings have gradually become more and more popular since the advent of the supersonic jet era, and research on the subject has become more detailed in order to be able to manoeuvre this pair of small wings more perfectly and effectively. This paper mainly studies the aerodynamic principle of the canard wings and the impact of its aerodynamic advantages on the efficacy and stealth performance of the aircraft under different aerodynamic stability and makes a comparative analysis with the horizontal tail. Through literature analysis and review as well as a small number of comparative analyses, this paper concludes that although canard wings can provide many aerodynamic advantages, they also have their limitations. Canards can only be effectively coupled when they are close to the main wing and longitudinally higher than or equal to the height of the main wings. The radar cross-section (RCS) characteristic of the canard wings will increase with the angle of its deflection.

A Cost-Effective Solution for Measuring Vibration and Impact on Small Twin Engine Electric Fixed Wing UAV

A Cost-Effective Solution for Measuring Vibration and Impact on Small Twin Engine Electric Fixed Wing UAV

A wind-direction adaptive piezoelectric energy harvester employing small wing passive control configuration

In this study, we propose a wind-direction adaptive piezoelectric energy harvester employing a small wing passive control configuration (WDEH-SW) for bidirectional wind energy harvesting. Our design significantly enhances bidirectional wind energy harvesting capabilities, addressing the limitations of traditional wind energy harvesters by modifying the aerodynamic characteristics of the bluff body via small wing rotations. Additionally, we introduce a criterion for determining the impact of wind direction changes on energy harvesting efficiency. Experimental comparisons with conventional galloping-based and vortex-induced vibration-based piezoelectric wind energy harvesters demonstrate the superior performance of the proposed structure. The experiment results indicate that the proposed structure effectively adapts to changes in wind direction, thereby preventing significant decrease or failure in energy harvesting efficiency. Compared to the conventional unidirectional galloping-based wind energy harvester, the proposed structure exhibits a 34.6% increase in 1.63 μW in power output, with an overall average output power reaching 6.35 μW. Notably, the proposed WDEH-SW shows an excellent wind direction adaptability and high output performance in both medium and low wind velocity ranges, providing valuable insights for designing compact bidirectional energy harvesters. This study showcases promising applications in self-powered micro-devices, particularly in straightforward bidirectional wind environments such as car or train tunnel entrances and exits.

Tympanal ears mediate male-male competition, courtship and mating success in Bicyclus anynana butterflies.

The presence of intra-specific acoustic communication in diurnal butterflies is not well established. Here, we examined the function of the tympanal ear (Vogel's organ, VO) in the seasonally polyphenic butterfly Bicyclus anynana in the context of sexual signalling. We investigated how the VO and the flanking enlarged veins, which are suggested sound resonance chambers, scale with wing size across sexes and seasonal forms, and how disruptions to the VO alter courtship behaviour and mating outcomes. We found that males have VOs similar in size to females despite having smaller wings, and dry season (DS) male cubital and anal veins do not scale with the wing size. This suggests that the VO plays an important role in males and that cubital and anal veins in DS males may be tuned to amplify specific sound frequencies. Behavioural assays performed with deafened and hearing males of different seasonal forms, in pair and triad settings, showed that deafened DS males, but not wet season males, experienced lower mating success relative to their hearing counterparts. Our study documents a novel function for the wing tympanal membrane in mediating courtship and mating outcomes in diurnal butterflies.

A test of trade-offs in dispersal and reproduction within and between a sister species pair of specialist insect herbivores.

Understanding the drivers of trade-offs among traits is vital for comprehending the evolution and maintenance of trait variation. Theoretical frameworks propose that evolutionary mechanisms governing trade-offs frequently exhibit a scale-dependent nature. However, empirical tests of whether trade-offs exhibited across various biological scales (i.e. individuals, populations, species, genera, etc.) remains scarce. In this study, we explore trade-off between dispersal and reproductive effort among sympatric sister species of wasps in the genus Belonocnema (Hymenoptera: Cynipini: Cynipidae) that form galls on live oaks: B. fossoria, which specializes on Quercus geminata, and B. treatae, which specializes on Q. virginiana. Specifically, our results suggest that B. fossoria has evolved reduced flight capability and smaller wings, but a larger abdomen and greater total reproductive effort than B. treatae, which has larger wings and is a stronger flier, but has a smaller abdomen and reduced total reproductive effort. These traits and the relationships among them remain unchanged when B. fossoria and B. treatae are transplanted and reared onto the alternative host plant, suggesting that trait divergence is genetically based as opposed to being a plastic response to the different rearing environments. However, when looking within species, we found no evidence of intraspecific trade-offs between wing length and reproductive traits within either B. fossoria or B. treatae. Overall, our results indicate that observed trade-offs in life history traits between the two gall former species are likely a result of independent adaptations in response to different environments as opposed to the amplified expression of within species intrinsic tradeoffs.

An Increase in the Energy Efficiency of Vortex Micro HPP with a Flexible Outlet Siphon by Self-Adjustment of Flows in the Pressure Chamber

The article aims to increase the energy efficiency of the vortex micro-power plant, which would be achieved due to its compatibility with the terrain. In particular, the inlet channel connected to the water intake of the pressure chamber and the water collector placed in the upper pool by transverse joints, and the flexible siphon connected by vertical and horizontal joints to the diffuser of the same chamber with a telescopic end. The boundary conditions were selected with parameters such as the water flow acceleration according to the river bed’s slope angle and the inclination angle of the upstream channel near the vertical pressure cone chamber. The level difference between the upper and lower pools was adjusted. Inside the pressure chamber, the inclined guides of the small wings were hinged to its wall and were adjusted by ballasts. The reactive forces generated by the upward reflection of the incoming flow from the surfaces on the inclined small guide wings of the pressure chamber were a factor in curbing the said flow (compensating for the insufficient volume flow) and ensuring the continuity of the water supply to the turbine in shallow water. The mentioned circumstances allowed for improving the synchronization of incoming and outgoing flows. As a result of the above improvements, an increase in the energy efficiency (i.e., annual electricity generation) of 15–20 % was achieved.

Местонахождение Шапи — новый памятник энеолита в Рын-песках Северного Прикаспия

Introduction. A continental stage in the Northern Caspian geological history began with the Mangyshlak regression when sands that would shape the Ryn Desert were freed from marine waters, and the region started being actively invaded by humans, which is evidenced by numerous Stone Age sites. The bulk of the latter are represented by ‘open-air’ materials — some mixed complexes with few ceramic remains — and this does complicate chronological attributions of such archaeological collections. So, the study of monuments with preserved ‘cultural layers’ instrumental in obtaining a series of absolute dates is a primary task in understanding historical and cultural processes of the Mesolithic/Eneolithic in the Northern Caspian. Goals. The article aims to introduce into scientific circulation some materials discovered at the site of Shapi in the Ryn-Peski Desert. Materials and methods. The site of Shapi is located in the north-northwest of the Ryn Desert, 30 km south of Lake Aralsor in present-day Bokey Orda District of West Kazakhstan Region. The stone artefacts obtained are few enough, mainly of quartzitic sandstone, and number 67, e.g., 6 items are tools — arrowheads, an arrowhead fragment, a notched piece, a flake with a distinguished point, and a flake with retouch. There are 8 flint artefacts, including 5 tools — an arrowhead, fragments of blades with retouch, and two flakes with retouch. A pit was dug out on the spot abundant in finds, and it yielded bone remains of cattle, goats and sheep, a horse, a camel, and a dog (wolf). Results. Despite tool forms are few enough, one can note the presence of pieces with bifacial retouch and concave-based arrowheads with small wings. Species composition analysis of the bone remains shows those are dominated by cloven-hoofed animals, essentials of the examined bone complex attest to these are kitchen waste. Bone remains at depths of 20–40 and 40–60 cm yielded a series of calibration dates between 4048 and 3956 BCE. Conclusions. Chronologically, the site clusters with Late Eneolithic ones, and may be attributed to the late Khvalynsk and Altata cultures.

Numerical Simulation and Flow Display of Bionic Alula on Rectangle Airfoils

Some birds have small wings (Alula) in the middle of their main wings. These small wings will tilt upward when the bird flies at a high attack angle to maintain a stable flying posture. This paper explores the lift effects of bionic Alula on rectangular airfoils with different aspect ratios through numerical simulation and flow display experiments. According to the numerical simulation, Alula can increase the rectangular airfoil lift coefficient by a maximum of 24% when the airfoil aspect ratio is 2. By comparing simulation results with flow display results, the low-pressure area generated by Alula and the merge of the Alula vortices with the airfoil tip vortices mainly contribute to the lift enhancement.

Aerodynamic Performance of an Unmanned Aerial Vehicle Wing For Varied Wing Geometric Parameters

The aerodynamic performance characteristics of a small unmanned aerial vehicle wing are evaluated computationally at a moderate Reynolds number of Re = 2.8 x 105. The flow exhibits laminar-turbulent transition and features a laminar separation bubble that exists for a substantial portion of the wing span. The flow near the wing tip is three-dimensional and exhibits complex flow patterns due to the interaction of the wing tip vortex with the laminar separation bubble. A series of systematic parametric studies are conducted by varying the wing geometric parameters like the span of the rectangular inboard wing, sweep of the outboard wing and wing dihedral angle. From the parametric studies, it is found that the wing with an outboard sweep of 17° has a 4.54 % improvement in endurance factor compared to the baseline wing at an angle of attack of 5°. The drag of this wing is 19.2 drag counts lower compared to the baseline wing. Further, flow transition is delayed for this wing. The present results show that wing sweep has a significant influence on the improvement of aerodynamic performance of unmanned aerial vehicle wings at moderate Reynolds numbers.

Osteological and historical data on extinct island night herons (Aves: Ardeidae), with special reference to Ascension Island, the Mascarenes and Bonin Islands

Night herons of the genus Nycticorax and Nyctanassa are adept island colonisers, occurring on a number of oceanic islands and island archipelagos. Continental species and those inhabiting large islands are generally not considered threatened, whereas night herons restricted to small, oceanic islands are particularly vulnerable to human interference. As a result, six out of nine described species and one subspecies, all derived from Nycticorax nycticorax, Nycticorax caledonicus or Nyctanassa violacea, are now extinct whereas a further three extinct species await description. The extinct island endemics generally exhibit morphological adaptations to an insular environment and diet, such as an increase or decrease in size, robust jaws and legs, and smaller wings with associated reduced flying ability than founding stock. Here I present an osteological comparison along with historical descriptions of the extinct, oceanic island night herons, with special reference to the Mascarene and Ascension fossil species, and Bonin Island subspecies, and show the degree of morphological changes between the founding and island taxa. I further discuss the reasons why they became extinct.

Global stability analysis of elastic aircraft in edge-of-the-envelope flow

Shock buffet on wings is a phenomenon caused by strong shock-wave/boundary-layer interaction resulting first in self-sustained flow unsteadiness and eventually in a detrimental structural response called buffeting. While it is an important aspect of wing design and aircraft certification, particularly for modern transonic air transport, not all of the underlying multidisciplinary physics is thoroughly understood. Building upon a single-discipline shock-buffet stability study, this work now investigates the impact of an elastic structure in these extreme flow conditions. Specifically, a triglobal stability analysis of a fluid–structure coupled system is presented, utilising the implicitly restarted Arnoldi method with a sparse iterative Krylov solver and novel preconditioner. Asymmetry resulting from a static aeroelastic simulation based on a finite-element model of the underlying geometry in a wind tunnel modifies the global modes of the earlier fluid-only symmetric full-span analysis. A flutter stability analysis at wind-tunnel flow conditions below shock-buffet onset finds no instability in the structural degrees-of-freedom, whereas in shock-buffet flow with globally unstable fluid modes additional marginally unstable structural (and fluid) modes emerge. The developed stability tool for coupled analysis is instrumental in identifying those physically relevant and strongly coupled modes where a standard pk-type (p being eigenvalue and k reduced frequency) flutter analysis fails. With the complementary computation of adjoint eigenmodes, the core of the instability is pinpointed to a relatively small wing area which may help to effect the control and delay of this detrimental transonic unsteadiness. We contribute to the question on how the presence of the elastic wing structure impacts on the otherwise pure aerodynamic three-dimensional shock-buffet dynamics.

Decoupling wing-shape effects of wing-swept angle and aspect ratio on a forward-flying butterfly.

The effect of wing shape on a forward-flying butterfly via decoupled factors of the wing-swept angle and the aspect ratio (AR) was investigated numerically. The wing-shape effect is a major concern in the design of a microaerial vehicle (MAV). In nature, the wing of a butterfly consists of partially overlapping forewing and hindwing; when the forewing sweeps forward or backward relative to the hindwing, the wing-swept angle and the AR of the entire wing simultaneously change. The effects of the wing-swept angle and AR on aerodynamics are coupled. To decouple their effects, we established wing-shape models with varied combinations of the wing-swept angle and AR based on the experimental measurement of two butterfly species (Papilio polytes and Kallima inachus) and developed a numerical simulation for analysis. In each model, the forewing and hindwing overlapped partially, constructing a single wing. Across the models, the wing-swept angle and AR of these single wings varied sequentially. The results show that, through our models, the effects of the wing-swept angle and AR were decoupled; both have distinct flow mechanisms and aerodynamic force trends and are consistent in the two butterfly species. For a fixed AR, a backward-swept wing increases lift and drag because of the enhanced attachment of the leading-edge vortex with increased strength of the wingtip vortex and the spanwise flow. For a fixed wing-swept angle, a small AR wing increases lift and decreases drag because of the large region of low pressure downstream and the wake-capture effect. Coupling these effects, the largest lift-to-drag ratio occurs for a forward-swept wing with the smallest AR. These results indicate that, in a flapping forward flight, sweeping a forewing forward relative to a hindwing is suitable for cruising. The flow mechanisms and decoupled and coupled effects of the wing-swept angle and the AR presented in this paper provide insight into the flight of a butterfly and the design of a MAV.

Dynamics simulation of folding wing UAVs launched from a high-altitude balloon platform

It is a new application of the high-altitude balloon system to launch multiple small folding wing unmanned aerial vehicles (UAVs). Based on the design of the launching system, we conduct numerical simulations of the ejection process from the balloon platform and the subsequent UAV wing deployment with trajectory leveling operation. We use the Kane method to establish the dynamic model of the balloon launching platform in the inertial coordinate system (ICS). By introducing the degree of freedom of UAV sliding along the sliding track, we realize the dynamic simulation of eight UAV launching processes and obtain the instantaneous separated states. The folding wing UAV first deploys its wings after ejection, which has the coupling characteristics between structural deformation and attitude adjustment. It is regarded as a multi-rigid body connecting structure composed of the fuselage and four wings. We establish the dynamic simulation model by the Kane method in the UAV body coordinate system (BCS). The Radau pseudo-spectral method is used to calculate the flight trajectory of each UAV. This paper is an engineering application research and can provide a simulation reference for the launching test of the balloon-borne folding wing UAV program.

Morpho-histological Study of the Nictitans Gland and Cartilage in Dogs and Cats in Sulaimani Province

This comparative study aims to assess the differences in the third eyelid gland and cartilage morphology and histology between dogs (Canis lupus familiaris) and cats (Felis catus). Twenty nictitans membranes were collected from 20 adult dogs and 20 adult cats. The nictitans membranes were dissected to examine the structure, shape, and positions of the nictitans gland and cartilage. Histologically, the samples were fixed in 10% neutral buffer formalin and then prepared for H&E stains. Generally, in both species, the cartilage consists of a long, slender body, and pigmented large dorsal and small ventral wings. The cartilage had a curving shape that resembled the eyeball's curvature and had two surfaces; palpebral and corneal or bulbar surface. At the basal end of the corneal surface, there are several lymph nodes aggregates. In the dogs, the nictitans cartilage was longer and slenderer than in the cats. The body of the cartilage was wrapped by a spherical and light pink nictitans gland in the dogs while the cats had oval nictitans gland. Microscopically, the nictitans gland in the dogs was composed of a compound tubuloacinar gland whereas; in cats, it was composed of a compound acinar gland. There was no difference histologically in the intralobular and the interlobar septa between species, the isogenous group of chondrocytes was higher in cats Vs. the dogs that showed few in number. In conclusion, the nictitans gland and cartilage were varied in their anatomical and histological structure. This should help researchers make preparations to prevent negative impacts and could help them investigate changes made more pronounced by disease conditions.

Effects of larval host and natural microsporidian infection on adult life history traits of the forest tent caterpillar (Lepidoptera: Lasiocampidae).

Host affiliation and entomopathogenic infections play a major role in shaping population dynamics of the forest tent caterpillar (FTC), Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae). The effect of these individual factors has been studied, but it is unknown whether interactions between these factors significantly impact FTC life history traits. In the laboratory, we investigated a tritrophic interaction among larval diet, larval microsporidian infection, and FTC life history traits. Larvae were reared on foliage of trembling aspen, Populus tremuloides Michx (Malpighiales: Salicaceae) or sugar maple, Acer saccharum Marshall (Sapindales: Sapindaceae), or an artificial diet. Natural levels of microsporidian infection were assessed through microscopy and categorized as none (0 spores), low (1-100 spores), or high (>100 spores). Microsporidian infection and larval diet individually, but not interactively, impacted FTC life history traits. Moths with high infection had smaller wings, but infection did not increase the probability of wing malformations. Wings of FTC reared on fresh maple foliage were significantly smaller, had a higher probability of wing malformation, and a lower likelihood of cocoon production than FTC reared on other diets, but displayed higher overall survival. While microsporidian infection did not influence FTC-diet interactions, we provide further evidence on how these main effects may individually contribute to shaping FTC adult life history traits, and, ultimately, cyclical population dynamics. Future research should consider how larval mortality, distinct infection levels, and geographical source of FTC populations affect this tritrophic interaction.

Structural Design and Analysis of Small Flapping Wing Aircraft Based on the Crank Slider Mechanism

In this project, the miniaturization of the aircraft was realized under the premise of strong maneuverability, high concealability, and driving a certain load, and the flight mode and structural characteristics of birds were imitated. A small bionic flapping wing aircraft was built. The flapping of the wing was realized by the crank slider mechanism, and the sizes of each part were calculated according to the bionics formula. The wingspan was 360.37 mm, the body width was 22 mm, the body length was 300 mm, the wing area was 0.05 m2, the flapping amplitude was 71°. ADAMS software was used to simulate the dynamics of the designed aircraft, and the variation of flapping amplitude and angular velocity during the movement of the aircraft was obtained, which verified the feasibility of the mechanism. The prototype aircraft was made for flight test, and the designed bionic flapping wing aircraft achieved the expected effect. It provides a theoretical basis and data support for the design and manufacture of small flapping wing aircraft.

Crucial DNA at crux of insect wing size evolution

Closely related species are usually remarkably similar. But take a closer look, and subtle differences begin to emerge. Some may have longer limbs or wider bodies, and some fruit fly species have dinky wings while the wings of relatives are relatively large. ‘The diversity of wing size relative to whole body size is remarkable in insects, but it is currently unclear how wing-to-body proportions have changed through evolution’, says Marcos Nahmad from the Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico. The proteins that control the development of wings are essentially the same across almost all fruit fly species, regardless of their physical differences, so how do these differences come about?Regions of DNA that control how the regulatory proteins are produced could tweak the way in which a limb develops. One member of the fruit fly family, Drosophila virilis, has petite wings compared with D. melanogaster and other species, which all have relatively large wings compared with their bodies. Knowing this, Nahmad and Timothy Evans (University of Arkansas, USA) wondered if a region of regulatory DNA found in the gene for a protein known as ‘vestigial’ – which controls wing growth – could be responsible for D. virilis’s smaller wings. If so, could D. melanogaster grow D. virilis-sized wings if Keity Farfán-Pira and Teresa Martinez-Cuevas (from Cinvestav-IPN) replaced the key section of D. melanogaster DNA with regulatory DNA from D. virilis?First, Farfán-Pira confirmed that D. virilis fruit flies develop smaller wings for their body size, and then she began the painstaking task of transferring a 1200 bp segment of D. virilis DNA from the section of DNA preceding the fly's vestigial gene into the correct place in the DNA of D. melanogaster eggs. In addition, the team added a gene that would turn the modified flies’ eyes fluorescent red, to be sure that the offspring produced by the D. melanogaster eggs carried the crucial D. virilis DNA.Eventually, after months of patience in the laboratory creating the genetically modified D. melanogaster eggs and then waiting for them to develop into flies, Farfán-Pira measured the wing and leg lengths of the insects and the team was astonished that the wings of the D. melanogaster carrying D. virilis DNA were far smaller for their body size than those of regular D. melanogaster. ‘We were shocked’, Nahmad admits. Inserting the D. virilis vestigial regulatory DNA sequence into the D. melanogaster vestigial gene was sufficient to make the flies’ wings smaller, like the daintier wings of D. virilis.But what does this discovery mean for how members of the insect family, ranging from flamboyant butterflies to stubby-winged bees, evolved such extensive wing differences given that they all use the same cellular machinery to coordinate wing development? The team suspects that the crucial section of vestigial gene DNA fine-tunes the distribution of the cell signalling proteins that regulate wing growth through the larvae's imaginal disk structure – which develops into the wings – to regulate wing size and allow the insect to develop either small or large wings, depending on their family history. The team concludes that some significant change in the key vestigial DNA segment occurred after the split between the D. melanogaster and D. virilis families, resulting in one branch of the family with relatively large wings while the other evolved their comparatively small wings, which persist to this day.

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Haemolymph viscosity in hawkmoths and its implications for hovering flight.

Viscosity determines the resistance of haemolymph flow through the insect body. For flying insects, viscosity is a major physiological parameter limiting flight performance by controlling the flow rate of fuel to the flight muscles, circulating nutrients and rapidly removing metabolic waste products. The more viscous the haemolymph, the greater the metabolic energy needed to pump it through confined spaces. By employing magnetic rotational spectroscopy with nickel nanorods, we showed that viscosity of haemolymph in resting hawkmoths (Sphingidae) depends on wing size non-monotonically. Viscosity increases for small hawkmoths with high wingbeat frequencies, reaches a maximum for middle-sized hawkmoths with moderate wingbeat frequencies, and decreases in large hawkmoths with slower wingbeat frequencies but greater lift. Accordingly, hawkmoths with small and large wings have viscosities approaching that of water, whereas hawkmoths with mid-sized wings have more than twofold greater viscosity. The metabolic demands of flight correlate with significant changes in circulatory strategies via modulation of haemolymph viscosity. Thus, the evolution of hovering flight would require fine-tuned viscosity adjustments to balance the need for the haemolymph to carry more fuel to the flight muscles while decreasing the viscous dissipation associated with its circulation.