Large Wing Research Articles

Analysis of Lateral Torsional Buckling Strength of Single Symmetric I Beam

This study evaluates the variation of the bending moment strength of the single symmetrical and double symmetrical I-beam design. This study compares the use of a double-symmetric I-section with a large, small flange, a single-symmetric I-section with a large compression and large tension flange. The study shows that the four sections have the largest wing strength with double-symmetric I-section, and the inelastic and elastic strengths are similar to those of the single-symmetric I-section, especially the elastic region is almost the same. In the plastic phase, the double symmetrical flanges have a high cross-sectional strength. In the inelastic phase, the intensity of two individual symmetrical sections of the same area is close to a double symmetrical section. The use of a single symmetrical I-beam can be preferred over a double-symmetric I-beam. This study provides a single-symmetric I-beam strength difference analysis, providing users with a variety of options for comparing cross-sections.

Interfacial Fracture Toughness Assessment of a New Titanium–CFRP Adhesive Joint: An Experimental Comparative Study

Adhesive joints between dissimilar layers of metals and composites are increasingly used by different industries, as they promise significant weight savings and, consequently, a reduction in energy consumption and pollutant emissions. In the present work, the interfacial fracture behavior of a new titanium–carbon fiber reinforced plastic (CFRP) adhesive joint is experimentally investigated using the double cantilever beam (DCB) and end-notched flexure (ENF) test configurations. A potential application of this joint is in future large passenger aircraft wings. Four characteristic industry relevant manufacturing approaches are proposed: co-bonding with/without adhesive and secondary bonding using thermoset/thermoplastic CFRP. For all of them, the vacuum-assisted resin transfer molding (VARTM) technique is utilized. To prevent titanium yielding during testing, two aluminum backing beams are adhesively bonded onto the primary joint. A data reduction scheme recently proposed by the authors, which considers effects such as bending–extension coupling and manufacturing-induced residual thermal stresses, is utilized for determination of the fracture toughness of the joint. The load–displacement responses, fracture behaviors during testing, and fracture toughness performances of the four manufacturing options (MOs) under consideration are presented and compared.

Multi-joint and Large Load Wing Load Processing Method

Multi-joint and Large Load Wing Load Processing Method

Butterfly-wing pollination inScadoxusand other South African Amaryllidaceae

AbstractUnderstanding the evolution of floral morphology requires information about the identity of pollinators as well as the specific mechanisms of pollen transfer. Based on preliminary field observations and floral structure, we hypothesized that pollination mechanisms involving the transfer of pollen on butterfly wings occur in several lineages of South African Amaryllidaceae. Here we report findings from a detailed study of butterfly-wing pollination in two subspecies of Scadoxus multiflorus and review the prevalence of this pollination mechanism among other Amaryllidaceae in southern Africa. We established that S. multiflorus subsp. katherinae is genetically self-incompatible and thus entirely reliant on pollinators for seed production. We determined that this subspecies is pollinated almost exclusively by large swallowtail butterflies, principally males of the mocker swallowtail Papilio dardanus cenea. Flowers of S. multiflorus subsp. multiflorus are pollinated by pierid and swallowtail butterflies. Pollen is deposited on the ventral surface of the wings of butterflies as they flutter over the strongly exserted stamens. We predict that butterfly-wing pollination occurs in at least nine species of South African Amaryllidaceae, which may reflect several independent origins of this mechanism. The flowers of these species are red or orange with strong herkogamy and are either bowl-brush or open-brush in shape. We provide maps of the distribution of pollen on the ventral surface of the wings of pollinators for four of these species. All four appear to be pollinated via the ventral surface of large butterfly wings, with the floral structure facilitating the process. These findings illustrate the importance of investigating pollen transfer mechanisms in order to understand patterns of floral diversification and floral convergence.

The Relationships Between Propolis Collecting Capability and Morphometric Features of Some Honey Bee Races and Ecotypes in Anatolia

Propolis collecting capacity of the honey bee race, Apis mellifera L., distributed across Anatolia and Thrace regions of Turkey was investigated and correlated with morphometric characteristics. Thus, the propolis collecting behaviour of honey bee races and ecotypes naturally have been in Turkey, Apis mellifera caucasica, Apis mellifera carnica, Apis mellifera syriaca and Yigilca and Mugla ecotype of Apis mellifera anatoliaca were monitored. The mean yield of annual propolis was recorded as the following; Yigilca ecotype (111.6±27.5 g colony) A. m. caucasica (104±20.7 g colony), Mugla ecotype (103±34 g colony), A. m. carnica (91.16±17.6 g colony), and A. m. syriaca (74±6.4 g colony) in descending order. The highest propolis collecting activity was recorded for the Yigilca ecotype of A. m. anatoliaca and A. m. caucasica. Morphological features of honey bee samples were evaluated by classic morphometric technique to correlate propolis collecting capability and morphological features. Morphometric results of the present study showed that the largest wing and leg lengths belonged to Yigilca ecotype of A. m. anatoliaca and A. m. caucasica. Furthermore, Pearson correlation showed a significant relationship between some morphometric characteristics including the proboscis and mandibular sections, wing length (WL), wing width (WW), femur length (FL), tibia length (TL), basitarsus length (BL), basitarsus width (BW), and propolis collecting capability (P<0.05). Therefore, it seems that the enlargement of certain morphological properties with genetic tendency of the honey bee races and ecotypes, primarily the legs and wings, can lead to better propolis collecting capability.

Neurosurgery in a Case of Suspected Prion Disease: Challenges Faced

AbstractThis report refers to a rare case of a patient with suspected prion disease and the steps taken for the infection control measures in postsurgical management of a large sphenoid wing meningioma. Stringent measures are needed to prevent the transmission of Creutzfeldt–Jakob disease (CJD) to other patients or healthcare workers. The main concern, especially in a neurosurgical case, is the handling of highly infective tissue and hence the higher risk of disease transmission. This report provides guidance based on the experience in this case, as an aid to similar surgeries.

An unusually large bird wing in mid-Cretaceous Burmese amber

All of the bird specimens previously recovered from Burmese amber have belonged to either immature specimens, or small-bodied taxa belonging to Enantiornithes. This has led to questions about whether the size bias inherent to preservation in amber has limited inclusions to smaller individuals or species, or if the avifauna of the amber-producing forest had a stronger representation of small-bodied taxa than other Cretaceous assemblages. A newly discovered inclusion of a fragmentary bird wing is described here: specimen LV-0321 likely belonged to an individual that was in excess of 10 cm long (snout to vent length). The new specimen also displays more prominent light-and-dark banding patterns among the primary flight feathers than any of the wings previously described from the deposit. In addition to increasing the known size range for enantiornithines within the assemblage, the new specimen sheds further light on the appearance of the plumage in these Cretaceous birds.

Research on active vibration control of flexible wing based on MFC actuator

An active vibration control scheme was proposed based on Macro Fiber Composite (MFC) actuators for the bending and torsional vibration control of large flexible lightweight wing structures. Firstly, a finite element modeling and modal analysis of a flexible wing are carried out. Further, the number, type, and location distribution of the MFC actuators bonded on the supported beam of the wing are designed. Then, the actuated characteristics of the two kinds of MFC actuators required for bending and torsional vibration controls was theoretically analyzed. The simulation model of the overall vibration control system was also finally obtained. Finally, through ANSYS simulation analysis, the vibration control effect of the current control system on the first two-order low-frequency modal response of the wing structure is given. The simulation results show that the proposed active vibration control scheme has specific feasibility and effectiveness.

An Innovative Control Allocation Framework for a Novel Tiltrotor Aircraft

Control allocation is still a challenge for tiltrotor aircraft due to effectors’ redundancy, dramatic nonlinearities and cross-coupling. Besides this, the external disturbance caused by the unique configuration of tiltrotor such as larger wing area and tiltable mechanism puts forward extra security requirement on control allocation method. Thus, this paper proposes an innovative control allocation framework from the perspective of flight safety to address this problem. Firstly, an effector distribution management scheme based on remaining control ability index (RCAI) is developed to reduce the effector saturation and ensure flight safety. Secondly, the energy consumption models for two classes of effectors: thrust vectoring and aerodynamic surfaces are introduced respectively for the subsequent optimization problem mathematically. Then, the null space transition is used to find the minimum-energy control input of effectors. Finally, key parameters of energy consumption model are identified by experiments. The real-time hardware-in-loop simulation platform is adopted to demonstrate the effectiveness of the proposed control allocation framework. Experimental results show that the energy consumption of proposed method can reduce by about 63.5% comparing to traditional control allocation method.

DNA barcoding reveals a species group of the genus Campiglossa (Diptera, Tephritidae, Tephritinae) with recognition of a new species from East Asia and previously unknown females of Campiglossa coei (Hardy).

While analyzing DNA barcodes of all the Korean and some East Asian tephritid species in conjunction with the barcode sequences available from BOLD Systems (www.boldsystems.org), the large and taxonomically enigmatic genus Campiglossa was recovered as a monophyletic clade, together with the genera Dioxyna and Homoeotricha, which are here synonymized for that reason. Ten major lineages are also recognized within the Campiglossa clade: producta group, loewiana group, sororcula group, irrorata group, achyrophori group, difficilis group, luxorientis group, magniceps group, arisanica group, and misella group. Here, more detailed taxonomic accounts are provided for the misella group, including four DNA analysis-recovered members: C. coei, C. misella, C. paramelaenasp. nov., and C. melaena. A single morphological synapomorphy is proposed for this species group: the presence of a large mid-anterior dark wing marking in males with associated structural modification (more apically positioned crossvein R-M than in females). Based on the morphological characteristics, two presumptive members that are only known from male specimens are further recognized: C. pishanica and C. propria from China. A full description of C. paramelaenasp. nov., and a redescription of C. coei, for which only males were previously known, are provided. For all the included species, a taxonomic key, diagnoses, and photographs to aid their accurate identification are given. Finally, C. favillacea is synonymized with C. coei and C. roscida with C. misella, and C. coei and C. pishanica resurrected from the synonymy of C. misella.

The multistep morphing of beetle horns.

Genes that specify insect wings initiate horn development in dung beetles

Multidisciplinary design and optimization of an innovative nano air launch vehicle with a twin-fuselage UAV as carrier aircraft

The population of nano satellites has increased dramatically in recent years, but there are few launch vehicles providing dedicated launch opportunities for them. This paper presents the conceptual design of an innovative nano air launch vehicle, dedicated to providing exclusive launch opportunity to nano satellites weighing 10 kg or less. This nano launcher is a three-stage launch vehicle carried by a twin-fuselage unmanned aerial vehicle and released at an altitude of 10 km from a velocity of 0.5Ma. The air launch vehicle is innovative in two senses: firstly, it adopts a novel air launch method. Before separation, the launch vehicle is adjusted to a large angle of attack by the carrier aircraft. The launch vehicle only needs to keep attitude stable after separation, and sequentially when first stage ignites, the orientation of the thrust is inclined upward so that the thrust can provide enough vertical force to pull up the flight path angle rapidly, without aid from large wings; secondly, a terminal lumped control unit is applied to undertake the flight control task on its own. The terminal lumped control unit is a combination of four thrusters that share the liquid propellant with the last stage's main engine. With the terminal lumped control unit, the air launch vehicle needs no movable attitude control instruments, including thrust vectoring gimbals and movable wings. This innovative flight control strategy makes the launch vehicle very simple in structure and light in weight. Multidisciplinary modeling of the nano launcher is performed and genetic algorithm is applied for optimization. Among all the disciplines, trajectory optimization is key in checking the feasibility of the design, for which the Radau pseudospectral method is successfully implemented to obtain the optimal ascent trajectory. The optimal nano launcher has a gross take-off weight of 1365 kg. Finally, a sensitivity analysis is performed to check the robustness of the result using Monte Carlo simulation method.

Limits to load-lifting performance in a passerine bird: the effects of intraspecific variation in morphological and kinematic parameters.

Although more massive flight muscles along with larger wings, higher wingbeat frequencies and greater stroke amplitudes enhance force and power production in flapping flight, the extent to which these parameters may be correlated with other morphological features relevant to flight physiology and biomechanics remains unclear. Intraspecifically, we hypothesized that greater vertical load-lifting capacity would correlate with higher wingbeat frequencies and relatively more massive flight muscles, along with relatively bigger hearts, lungs, and stomachs to enhance metabolic capacity and energy supply, but also with smaller body size given the overall negative allometric dependence of maximum flight performance in volant taxa. To explore intraspecific correlates of flight performance, we assembled a large dataset that included 13 morphological and kinematic variables for a non-migratory passerine, the Eurasian tree sparrow (Passer montanus). We found that heavier flight muscles and larger wings, heavier stomachs and shorter bills were the most important correlates of maximum load-lifting capacity. Surprisingly, wingbeat frequency, wing stroke amplitude and masses of the heart, lungs and digestive organs (except for the stomach) were non-significant predictor variables relative to lifting capacity. The best-fit structural equation model (SEM) indicated that load-lifting capacity was positively correlated with flight muscle mass, wing area and stomach mass, but was negatively correlated with bill length. Characterization of individual variability in flight performance in a free-ranging passerine indicates the subtlety of interaction effects among morphological features, some of which differ from those that have been identified interspecifically for maximum flight performance in birds.

ZERO EMISSION SAILING SHIP – CONCEPTUAL DESIGN –

When a sailing ship which has large rigid wing sails such as the Wind Challenger Sail runs in a sufficiently windy sea, the thrust by sails is utilized to not only drive the ship at the proper speed but also to rotate an underwater turbine at significant speed and torque. The turbine generates electricity which is used for the electrolysis of water to generate hydrogen. The hydrogen is stored using toluene in the form of methylcyclohexane (MCH), which is in liquid form under normal temperature and pressure. MCH is stored in the ship's tank as hydrogen fuel. In the case of weak winds when the sails cannot generate sufficient thrust, using the hydrogen generated by the dehydrogenation device, the fuel cell works and supplies electricity to the electric motor propeller for the ship's propulsion. Thus, the ship can run at a constant speed regardless of wind speed and direction.

Wing polymorphisms of Pterostichus melanarius (Coleoptera: Carabidae) (Illiger, 1978) in Alberta pulse crops

In a 6 week research project, a wing-dimorphic carabid species was studied to identify the proportions of macropterous (large functional wings) individuals and brachypterous (short, rudimentary wings) individuals from different pulse growing regions of Alberta. Pterostichus melanarius I. (Coleoptera: Carabidae) can be short-winged (SW) due to brachyptery being a dominant gene or long-winged (LW) individuals causing macroptery. Although macroptery is a recessive trait, the LW morph persists through the recolonization of populations due to human disturbance. Their ability to fly facilitates their dispersal across Alberta to uncolonized areas. Samples of P. melanarius were captured as bycatch from pea leaf weevil, Sitona lineatus L. (Coleoptera: Curculionidae) pitfall traps from the East, Capital, and Central regions of Alberta. Traps were positioned on a 175 meter transect pea and faba field margins in spring and again in the fall. Captured P. melanarius were identified and separated by collection site and date and stored in 95% ethanol until measurements. The beetles from the bycatch samples were sexed using tarsal characteristics. Anterior tarsal segments of the front pair of tarsi are dilated in males and normal in females. After being identified and recorded as “M” or “F”, they were mounted on a foam board with insect pins for measurement. The elytra (forewings) length and width was measured followed by measurement of their hindwings. They were classified as “SW” or “LW” depending on the functionality of their wings. Out of 440 individuals from the Capital region, 17.1% of captured P. melanarius were LW and 83.0% were SW. From the Central region 21.6% of 495 beetles were LW and 83.4% of them were SW. In the East region less P. melanarius were captured and from 94 individuals, 46.8% were LW and 53.2% were SW. Macropterous individuals are more common in the East region due to recolonization of populations whereas in the Central and Capital region the proportions of SW are much larger. In regions that have established populations of P. melanarius the proportions of SW are greater than LW.

Comparative analysis of the internal and external outlines of wings for an outline-based geometric morphometric approach to distinguish three Aedes mosquitoes (Diptera: Culicidae) in Thailand

Aedes mosquitoes belong to a subgenus of Stegomyia (Diptera: Culicidae), which are dengue and chigunkunya vectors, including Aedes aegypti, Ae. albopictus, and Ae. scutellaris, and have a worldwide distribution in tropical and subtropical regions. Species identification of mosquitoes is challenging yet necessary to select appropriate control methods for each species. In this study, we have analyzed the different wing components for identification to find the optimal outline for Aedes mosquito analysis by an outline-based GM approach. Two internal and external outlines of the wing were considered for Aedes species identification in this study. A total of 90 Aedes wings were analysed, divided into 30 wings per species (Ae. aegypti, Ae. albopictus, and Ae. scutellaris). The results showed that the mean size of Ae. albopictus had the largest wings, followed by Ae. Aegypti, and Ae. scutellaris, respectively, in all the internal and external outlines. While, the shape analysis in the three outlines were expressed by the factor map, the statistical difference and cross-validated classification scores indicated the ability of the outline-based GM approach to distinguish species of Aedes mosquitoes. The external outline has a relatively good range of cross-validated classification scores compared to the other internal outlines. The results of this research reveal the suitability of this external outline to identify species of Aedes vectors in Thailand.

Large Hind Wings Enhance Gliding Performance in Ground Effect in a Neotropical Butterfly (Lepidoptera: Nymphalidae)

AbstractNeotropical butterflies in the nymphalid genera Pierella Herrich-Schäffer, 1865 (Lepidoptera, Nymphalidae) and Cithaerias Hübner, 1819 (Lepidoptera, Nymphalidae) are known to glide near ground level, and have a high forewing aspect ratio. The hind wings of Pierella are proportionately larger than those of Cithaerias, suggesting a potential role in gliding flight. We show that Pierella helvina (Hewitson, 1860) (Lepidoptera, Nymphalidae) is capable of gliding for longer periods of time than Cithaerias pireta (Stoll, 1780) (Lepidoptera, Nymphalidae) both in the field and a laboratory setting. Experimental reduction of hind wing area in P. helvina led to a decrease in male gliding performance, and an increase in female wing-beat frequency. We also found that escape velocity decreased in both sexes after hind wing area reduction, but the effect was strongest in females. Although the increased drag associated with large hind wings could be detrimental to gliding flight, the large hind wing area of P. helvina effectively enhances gliding performance in ground effect. This study is the first to investigate the role of hind wings on butterfly gliding performance.

Numerical study of flexible flapping wings with an immersed boundary method: Fluid–structure–acoustics interaction

The fluid–structure–acoustics interaction of flexible flapping wings is numerically studied by using an immersed boundary method at a Mach number of 0.1. In this study, a wing flapping in a uniform flow with prescribed leading edge motion is considered. Apart from rigid wings, flexible wings of various bending rigidities and mass ratios are also examined. By using a direct numerical simulation technique, the sound generation mechanism is identified. The numerical results show that the wing with combined translational and rotational motion generates smaller sounds than the translating wing, and larger rotational angles transform the dipole sound to a monopole one. Similar sound fields are observed among all these wings, except that the direction of the sound shifts to the downstream for large flexible wings. Frequency analysis shows that the sound is dominated by the flapping frequency and two times of the flapping frequency in the vertical and horizontal directions, respectively. The results also show that the thrust increases first then decreases with bending rigidity for all three mass ratios considered, and the lighter wing suffers more decrease. However, the fluctuating pressure for the three mass ratios varies significantly. Specifically, it increases significantly with the decreasing bending rigidity when the structural inertia is dominating at m∗=5.0; but it experiences a reduction contrarily when the aerodynamics becomes dominant at m∗=0.5; for the medium mass ratio at m∗=1.0, no significant effects are observed. The comparisons indicate that the flexible wing with a lower mass ratio (e.g. m∗=0.5) and a medium flexibility (e.g. ω∗=0.3) achieves lower sound generation without significant thrust decrease. In addition, the sound on the windward side is pronounced significantly when the wing is flapping with a stroke plane angle less than 90o. The present results can expand the currently limited database of fluid–structure–acoustics interaction, and also provide an insight for the optimization of flight vehicle using flapping wing.

Morphological Murals: The Scaling and Allometry of Butterfly Wing Patterns.

The color patterns of butterflies moths are exceptionally diverse, but are very stable within a species, so that most species can be identified on the basis of their color pattern alone. The color pattern is established in the wing imaginal disc during a prolonged period of growth and differentiation, beginning during the last larval instar and ending during the first few days of the pupal stage. During this period, a variety of diffusion and reaction-diffusion signaling mechanisms determine the positions and sizes of the various elements that make up the overall color pattern. The patterning occurs while the wing is growing from a small imaginal disc to a very large pupal wing. One would therefore expect that some or all aspects of the color pattern would be sensitive to the size of the developmental field on which pattern formation takes place. To study this possibility, we analyzed the color patterns of Junonia coenia from animals whose growth patterns were altered by periodic starvation during larval growth, which produced individuals with a large range of variation in body size and wing size. Analyses of the color patterns showed that the positions and size of the pattern elements scaled perfectly isometrically with wing size. This is a puzzling finding and suggests the operation of a homeostatic or robustness mechanism that stabilizes pattern in spite of variation in the growth rate and final size of the wing.

Experimental and Numerical Study into 3D Crack Growth from a Spherical Pore in Biaxial Compression

A series of specimens made from transparent casting resin, each with a spherical pore at the centre of specimen were tested in a polyaxial stress state with different stress ratios ($$ \sigma_{x} /\sigma_{y} $$) between the lateral (the intermediate principal stress, $$ \sigma_{x} $$) and the axial (the major principal stress, $$ \sigma_{y} $$) loads, and the minor principal stress ($$ \sigma_{z} $$ ) was equal to 0, i.e., biaxial compression. The experimental results revealed the dramatic influence of the intermediate principal stress on the mechanics of 3D crack growth from a spherical pore. In uniaxial compression, the initial spherical pore produces several differently oriented wing cracks which are relatively short, smaller than the pore diameter (referred to as wing crack wrapping). In biaxial compression even with relatively low intermediate principal stress, a large wing crack is formed growing to an extent sufficient to split the specimen. The threshold for the intermediate principal stress separating these two regimes of wing crack growth is found to be 8.5% of the major principal stress. The results obtained from finite element method modelling show that with the intermediate principal stress above this threshold the directions of most of the secondary principal stresses (tensile) along the lateral surface of the initial pore are roughly perpendicular to the intermediate principal compressive stress direction. For the intermediate principal stress below the threshold, the directions of the secondary principal tensile stresses near the lateral surface of the initial pore are distributed in radial directions with respect to the initial pore. Results of numerical modelling also show that when transition is made from spherical pore to oblate pores, this threshold increases.