Wing Area Research Articles

МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ДВИЖЕНИЙ МАШУЩЕГО КРЫЛА ПРИ ВЗАИМОДЕЙСТВИИ С СОПРОТИВЛЯЮЩЕЙСЯ СРЕДОЙ

The work objective. The paper deals with the issues of modeling biologically inspired movement of an unmanned flying platform (UFP) equipped with flapping wings. Special attention is paid to modeling the interaction of a flapping wing with a resisting air medium. Therefore, the study aim is mathematical modeling of the force which occurs when the wings interact with the resisting medium.
 The problem to which the paper is devoted. To solve the problem is to make the mathematical model of the rotational motion of drone wing taking into account kinematic and dynamic features of two-coordinate rotation for various angle changing relative to the longitudinal and transverse axes.
 Research methods. Methods of classical mechanics, theory of motion stability, optimal control, observations, parametric optimization were used to solve the problem.
 The novelty of the work lies in the algorithms for changing the angles of wings rotation relative to the longitudinal and transverse axes, presented as smooth functions. A method for defining the reduced force arising during the wing movement is proposed. The dependences of the reduced force of wing-air interaction are obtained which provide the development of lifting and traction forces. These forces allow the drone to move in space along a given trajectory.
 The study results. The modes of flapping wing motion are simulated and the dependences of instantaneous force values which the wing creates during movement are obtained. These forces allow the drone to move in space along a given trajectory. It is shown that the drone movement is controlled by changing the frequency and amplitude of the wing vibrations, as well as by changing the angle of theneutral line inclination relative to which the wing rotates.
 Conclusions: a model of the reduced force arising from the flapping wing movement is proposed. Dependence graphs of the effective wing area (frontal area) for various parameters of changing rotation angles from time are constructed. Flapping wing motions of the aircraft is simulated. The range of parameters is defined at which the wing movement projections create horizontal F1x and lifting F1z forces at different values of area projections S1x, S1y, S1z.

Effect of spanwise slit on hydrodynamic characteristics of biplane hyper-lift trawl door

To improve the lift performance of the biplane-type otter board with a high aspect ratio, a monoplane-type hyper-lift trawl door (HLTD) with a spanwise slit h was designed by vertically assembling a pair of square HLTD models. Flume experiments were conducted using four models with slit ratio s (= h/c, c: chord) changed to 0, 0.1, 0.2, 0.3. Experiment results coupled with a CFD analysis revealed that the wingtip flow generated from the 0.2c slit is beneficial for suppressing the flow separation at moderate to high angles of attack, associated with increased lift and drag coefficients. Based on these results, a monoplane HLTD with a slit ratio of 0.2 was adopted for the fore wing, rear wing, and both wings of the biplane HLTD (composed of two monoplane HLTDs), denoted as model A, model B, model C. Flume experiments showed that model B was superior with a maximum lift coefficient of 2.18 (stall angle: 32°) in the free stream and 2.22 (28°) near the bottom. A bottom-trawling sea trial for the new biplane HLTD design (model B) was conducted. The new biplane HLTD with 80% of the wing area spread about 1.3 times more than the comparative biplane-type otter board.

Experimental surrogate-based design optimization of wing geometry and structure for flapping wing micro air vehicles

We present the experimental design optimization of a flapping wing and the development of a non-circular gear based flapping mechanism to enhance the propulsive efficiency of a flapping wing micro air vehicle (FWMAV). The proposed flapping mechanism consists of a very simple structure, which excludes any linkages but utilizes non-circular gears to achieve a desired flapping amplitude and angular velocity. An optimal wing was obtained via a surrogate-based global optimization reflecting the noise generated from the experiments. Compared to the baseline wing, the optimal wing was improved more than three times in terms of propulsive efficiency. The analysis showed that one of wing geometric parameters, the non-dimensional radius of second moment of area rˆ2, plays an essential role in designing an optimal wing. To achieve high efficiency, rˆ2 should decrease as the wing area increases. Simultaneously, rˆ2 determined other optimal values of geometry parameters such as aspect ratio and camber angle. Furthermore, rˆ2 was also closely related to an optimal vein position which not only generated a moderate wing angle of attack but also reduced the adverse effect of angle of attack fluctuation. Through the optimal wing and the proposed flapping mechanism, we could be able to achieve better efficiency and robust manufacturing compared with the previously reported tailless-FWMAVs.

Bmmp influences wing morphology by regulating anterior-posterior and proximal-distal axes development.

Insect wings are subject to strong selective pressure, resulting in the evolution of remarkably diverse wing morphologies that largely determine flight capacity. However, the genetic basis and regulatory mechanisms underlying wing size and shape development are not well understood. The silkworm Bombyx mori micropterous (mp) mutant exhibits shortened wing length and enlarged vein spacings, albeit without changes in total wing area. Thus, the mp mutant comprises a valuable genetic resource for studying wing development. In this study, we used molecular mapping to identify the gene responsible for the mp phenotype and designated it Bmmp. Phenotype-causing mutations were identified as indels and single nucleotide polymorphisms in noncoding regions. These mutations resulted in decreased Bmmp messenger RNA levels and changes in transcript isoform composition. Bmmp null mutants were generated by clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated protein 9 and exhibited changed wing shape, similar to mp mutants, and significantly smaller total wing area. By examining the expression of genes critical to wing development in wildtype and Bmmp null mutants, we found that Bmmp exerts its function by coordinately modulating anterior-posterior and proximal-distal axes development. We also studied a Drosophila mp mutant and found that Bmmp is functionally conserved in Drosophila. The Drosophila mp mutant strain exhibits curly wings of reduced size and a complete loss of flight capacity. Our results increase our understanding of the mechanisms underpinning insect wing development and reveal potential targets for pest control.

Benchmark of different aerodynamic solvers on wing aero-propulsive interactions

Distributed electric propulsion is a fertile research topic aiming to increase the wing aerodynamic efficiency by distributing the thrust over the wing span. The blowing due to distributed propulsors shall increase the wing lift coefficient for a given planform area and flight speed. This should bring several advantages as wing area, drag, and structural weight reduction, which in turn reduce fuel consumption, allowing airplanes to fly more efficiently. However, there are no consolidated preliminary design methods to size a distributed propulsion system. Numerical analysis is then performed at early stage, where many design variables have not been fixed yet. Therefore, the design space is vast and exploring all the possible combinations is unfeasible. For instance, low-fidelity methods (VLM, panel codes) have a low computational time, but usually they do not account for flow separation and hence they are unable to predict the wing maximum lift. Conversely, high-fidelity codes (CFD) provide more realistic results, but a single drag polar sweep can last days. This work provides a benchmark of different aerodynamic solvers for a typical regional turboprop wing with flaps and distributed propulsion, to better understand the limits of each software in the prediction of aero-propulsive effects.

Design and Numerical Simulation of Biomimetic Structures to Capture Particles in a Microchannel

The study of separating different sizes of particles through a microchannel has been an interest in recent years and the primary attention of this study is to isolate the particles to the specific outlets. The present work highly focuses on the design and numerical analysis of a microchip and the microparticles capture using special structures like corrugated dragonfly wing structure and cilia walls. The special biomimetic structured corrugated wing is taken from the cross-sectional area of the dragonfly wing and cilia structure is obtained from the epithelium terminal bronchioles to the larynx from the human body. Parametric studies were conducted on different sizes of microchip scaled and tested up in the range between 2–6 mm and the thickness was assigned as 80 µm in both dragonfly wing structure and cilia walls. The microflow channel is a low Reynolds number regime and with the help of the special structures, the flow inside the microchannel is pinched and a sinusoidal waveform pattern is observed. The pinched flow with sinusoidal waveform carries the particles downstream and induces the particles trapped in desired outlets. Fluid particle interaction (FPI) with a time-dependent solver in COMSOL Multiphysics was used to carry out the numerical study. Two particle sizes of 5 µm and 20 µm were applied, the inlet velocity of 0.52 m/s with an inflow angle of 50° was used throughout the study and it suggested that: the microchannel length of 3 mm with corrugated dragonfly wing structure had the maximum particle capture rate of 20 µm at the mainstream outlet. 80% capture rate for the microchannel length of 3 mm with corrugated dragonfly wing structure and 98% capture rate for the microchannel length of 2 mm with cilia wall structure were observed. Numerical simulation results showed that the cilia walled microchip is superior to the corrugated wing structure as the mainstream outlet can conduct most of the 20 µm particles. At the same time, the secondary outlet can laterally capture most of the 5 µm particles. This biomimetic microchip design is expected to be implemented using the PDMS MEMS process in the future.

Flight activity and age cause wing damage in house flies.

Wing damage attenuates aerial performance in many flying animals such as birds, bats and insects. Insect wings are especially light in order to reduce inertial power requirements for flight at elevated wing flapping frequencies. There is a continuing debate on the factors causing wing damage in insects, including collisions with objects, mechanical stress during flight activity, and aging. This experimental study addressed the reasons for and significance of wing damage for flight in the house fly Musca domestica. We determined natural wing area loss under two housing conditions and recorded flight activity and flight ability throughout the animals' lifetime. Our data show that in animals with eventually pronounced damage, wing damage occurs on average after 6 h of flight, is sex specific and depends on housing conditions. Statistical tests show that physiological age and flight activity have similar significance as predictors for wing damage. Tests on freely flying flies showed that minimum wing area for active flight is approximately 10-34% below the initial area and requires a left-right wing area asymmetry of less than approximately 25%. Our findings broadly confirm predictions from simple aerodynamic theory based on mean wing velocity and area, and are also consistent with previous wing damage measurements in other insect species.

Morphological characteristics of plate like setae encasing the wings of tiny grass blue “Zizula hylax”

Background: Butterfly wings are covered by tiny, coloured plate like setae called scales. Zizula hylax the ‘tiny grass blue’ is a small sized butterfly which belongs to the ‘Lycaenids’ or blues family. It is characterised by the dull violet blue appearance on the dorsal wing area and, they are pale grey with multiple arcs of brown dashes, brown border termen surrounded by numerous cilia on their ventral wing area. Objective: To investigate the wing scale morphology and length & width of scales using micrometry. Methods: ‘Zizula hylax’ is collected using handheld insect net in which they are pinned into the insect box. The method of Grodnitsky and Kozlov (1991) [5] was followed. The scales were scrapped off from distinct regions of dorsal and ventral wing separately which is taken in different glass slides. The sample is fixed with xylene when evaporates is studied under light microscope. Photographs were taken to record the images which is viewed under the light microscope. Micrometry is used to measure the length and width of the scales. Results: A total of 151 wing scales were analysed. 62 varieties of scales were studied from the dorsal blue coloured wing area and 89 varieties of scales were studied from the ventral ash coloured wing area. A typical scale consists of an abwing or upper lamina which constitute the upper portion of scale, an adwing or lower lamina which constitute the lower portion of the scale and a stalk. Several transverse lines run on the surface of the scales. Study on dorsal wing scales shows several dull black, pale yellow and dull brown coloured scales with flat and short size. Denudations of the scales are not well defined. The structural scales form the blue colour on the dorsal surface. The blue colour is formed when the light passes through the pale black, brown and yellow scales present in this region. The dimensions of the wing scales ranges between 74.86µ-94.56µ in length and 55.16µ-74.86µ in thickness. The ventral wing scales shows several long- narrow scales unlike the dorsal side. The ventral side of the ‘Zizula hylax’ is ash coloured and 89 scales were identified. All are transparent and glassy type white scales. Some flat white scales have also been seen. Here, the denudations are not yet clearly defined. The transverse lines can be seen clearly. The dimensions of the scale’s ranges between 82.74µ-177.3µ in length and 55.16µ-74.86µ in thickness. Conclusion: The present study provides an idea about the different types of scales, their morphology and size mainly the length and width. Scales play an important role in the life of butterfly as it aids in flight, predator defence, thermoregulation, camouflage, mimicry, and coloration. Studies on wing scales possess many bioinspired applications also.

Age and activity take their toll on house fly wings

Choosing a name can be stressful, so some creatures have simply ended up with literal monikers. Sloths, dung beetles and anteaters pretty much do what their names suggest; or at least they do in English. And then there's the humble fly. Where would these insects be without their wings? This is a question that Fritz-Olaf Lehmann from the University of Rostock, Germany keeps asking. How does the wear and tear that fly wings endure come about? Do the delicate structures simply become more fragile and disintegrate with age, or are they vulnerable to the knockabout of flight and collisions, accumulating damage over time? To find out where and how house flies accumulate damage to their wings, Henja-Niniane Wehmann, Thomas Engels (both from the University of Rostock) and Lehmann teamed up to identify which factors take the greatest toll on house fly wings and how much damage individuals can sustain before they can no longer remain aloft. Initially, Wehmann placed groups of four house flies (Musca domestica) together in small (130 cm3) plastic tubes for their entire lives, monitoring their activity by listening in as the insects buzzed while flying. In addition, she anaesthetised the tiny inhabitants three times a week to trace the outline of their wings and check their deterioration under a microscope. As well as cramming flies together, Wehmann also kept 20 of the insects in a larger mesh enclosure – providing 2000 times more space – regularly photographing them to find out how much of a toll the alternative lifestyle took on their wings.Recording almost 7.7 million flights, ranging from as little as 0.03 s (five wing beats) to 0.92 s for females, but only up to 0.79 s for the males, Wehmann and Engels realised that the insects’ wings first began incurring damage at the tips and rear edges of the fragile transparent membrane, becoming more ragged. However, after about 6 h of flight, the wings began showing signs of really catastrophic damage, fracturing along the front edge and losing larger portions. One fly lost almost 90% of a wing over one calamitous 3 day period.Yet, while there were some clear losers, there were also winners. Some of the closely caged insects lost only 15% of their wing area over their lifetime, while others were left with almost non-existent stubs by the time they died. Also, the flies that were living in the most cramped conditions suffered damage 20 times faster than the insects that had a spacious cage to explore, confirming that impacts contribute significantly to incurred wing damage.In contrast, some of the grounded flies appeared to have lost only 10% of their wing area, while others still managed to remain aloft, having lost as much as 34% of their initial wing area. And when Wehmann plotted the insects’ ages against their ability to fly, it was clear that the most elderly flies were the most likely to have lost the power of flight; age in addition to wear and tear, is a clear risk for wings.So, use and getting old both take a toll on the fragile structures that carry flies through the air, but the team suspects that other factors also play a role. For example, once a vein has become damaged, the wing may dry out faster, leaving it more vulnerable to damage from even the gentlest knock, accelerating the process. Wehmann also warns researchers that they shouldn't rely on the state of an insect's wings to estimate its age: ‘the variability between wings and individuals is too great’, she explains.

Research on the Influence of Natural Wind Pressure in Deep Mines on Ventilation Stability

Deep mines are greatly affected by changes in natural wind pressure because of their large buried depths and long ventilation paths. Changes in natural wind pressure do affect the air flow of the underground ventilation system, and even change the direction of individual branches. If the dynamic changes of natural wind pressure are not monitored constantly, it is very likely to cause disasters such as gas overrun and may even lead to heavy casualties. In this paper, the changes of natural wind pressure and the air volume entering the mine are measured on‐site in the 630 mining area in the south wing of Tangkou Coal Mine, Then, compare the change law of natural wind pressure with the change law of ventilation air volume. Finally, through numerical simulation by FLUENT, the change of internal flow in the gob where there is a loosely closed condition is simulated. Through research, the annual natural wind pressure change and the change of air intake in the 630 mining area of the south wing of Tangkou Coal Mine were obtained; The influence of changes in external conditions on the ventilation air volume of deep mines is obtained; The importance of the influence of natural wind pressure on the stability of the deep mine ventilation system is verified.

Aerodynamics effect of holes in UAV wings modified for VTOL capability

This research investigates the possibility of modifying the X8 Skywalker from a fixed-wing unoccupied aerial vehicle into a convertiplane to utilize the advantages of vertical take-off and landing and maintain the benefits of fixed-wing design. In this study two configurations were tested; the first one includes sharp holes embedded in the wings for the propellers and the second one has filleted holes. The purpose of the study is to analyze the new configurations’ ability to generate enough lift after reducing the wings area. The aerodynamic coefficients are calculated through computational fluid dynamics. Simulation results were validated experimentally by using the wind tunnel. Even though the holes reduced the wing area by about 20%, the proposed modifications could lead to a lift to drag ratio around 7. The results showed that the new configurations can generate five times the lift compared to the drag, while the maximum lift to drag ratio dropped by 50% compared to the original design. At the same time, the filleted hole configuration showed less drag and turbulence effects, especially at a low angle of attack, compared to the sharp hole configuration.

长白山9种槭树的翅果扩散及种子萌发研究

PDF HTML阅读 XML下载 导出引用 引用提醒 长白山9种槭树的翅果扩散及种子萌发研究 DOI: 10.5846/stxb202101060058 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家科技基础资源调查项目（SQ2019FY010110） Dispersal and germination of nine maple (Acer, spp) trees in Changbai Mountain area Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:翅果的风媒传播是槭属植物的主要扩散方式之一，且与种子萌发有着密切关联，但具体机理一直还并不明确。以分布于长白山的9种槭树为对象，探讨翅果的形态特征，测定它们在空气中的垂直沉降速度、不同风速下的水平扩散距离以及在扩散距离上的种子萌发率，进而比较并分析翅果的形态性状与沉降速度、水平扩散距离的相关性以及萌发率在不同扩散距离上的差异性。结果表明：（1）9种槭树的翅果长、宽和面积与沉降速度、水平扩散距离均呈负相关；尽管如此，翅果形态并不是风传播物种的最佳分类指标，而翅载力能较好地反应物种的风传播能力；（2）翅果垂直沉降速度和水平扩散距离间存在显著负相关，表明沉降速度越小，翅果在空气中停留的时间越长，水平方向上扩散距离越远，且强风有助于提高翅果的扩散能力；（3）沉降速度最慢的花楷槭在不同风速下的水平扩散距离均最远，而沉降速度最快的拧筋槭水平扩散距离最短；（4）种子萌发率随扩散距离的增加呈下降趋势。上述结果不仅为深入理解翅果的风力传播机制以及种子萌发对水平扩散距离的响应机制提供科学依据，还可为种群实生更新方面的理论研究提供参考。 Abstract:Anemochory is the main dispersal mode of Acer plants and has close relationship with seed germination, but the specific mechanism has not been clear. In this study, the samara of nine maple trees that distributed in Changbai Mountain were dropped in still air to simulate their descent velocity and horizontal dispersal distance under different wind speeds, and seed germination at the horizontal dispersal distance. Correlation and difference between morphological characteristics of samara and descent velocity, horizontal dispersal distance, germination rate were analyzed. The results showed that:(1) the samara length, samara width, and wing area of nine maple trees were negatively correlated with descent velocity and horizontal dispersal distance. The samara morphology traits were not the best index for classification of anemochory species, but the wing load could better reflect the wind dispersal ability. (2) The descent vertical was negatively correlated with the horizontal dispersal distance, indicating the smaller the descent velocity was, the longer a samara stays in the air, the farther it can be blown by the wind, and the longer the horizontal dispersal distance was. (3) A. ukurunduense, with the slowest descent velocity, has the farthest horizontal dispersal distance, while A. triflorum, with the fastest descent velocity, has the shortest horizontal dispersal distance, but the strong wind is helpful to improve the dispersal ability. (4) The seed germination rate decreased with the increase of the horizontal dispersal distance. The results can provide a scientific basis for the anemochory mechanism of samara and the response mechanism that seed germination to horizontal dispersal distance, and also provide a reference for the theoretical study of its population regeneration. 参考文献 相似文献 引证文献

Multiplanes of the New and Old Worlds

This article for the first time expounds on the history of development and construction of multiplanes (having at least four wings) worldwide before the beginning of World War I. Five ideas are identified that led the designers to what at the first glance appeared to be an irrational design of a multiplane. These were not only increasing the total wing area and a desire to increase the wing aspect ratio to enhance the lift / drag ratio but also using the lattice wings to prevent air flow along the wingspan, tandem wing boxes to increase longitudinal stability, and a design of tandem monoplane on a moving frame to increase stability at high angles of attack and ensure efficient pitch control. The article lists 39 multiplane models built during that period, and specifies the ideas that guided their designers. It is shown that the interest in multiplanes in the USA and the UK was disproportionally high compared to other countries. It is proposed what it could have been associated with. It is stated for the first time that there has been not one but two different J. Zerbe’s quintaplanes. We provide an example of how statistical analysis of technical designs can help in the evaluation of the extent of originality of a country’s construction school.

Investigation of Wing, Fuselage and Tail Design Parameters in Boeing and Airbus Aircraft

The study aims to examine the wing, fuselage and tail design parameters of Airbus and Boeing aircraft and to reveal the design criteria for the sizing of large commercial jets. Tin the study, the design and sizing data of 11 Airbus models and 14 Boeing models were compiled. The number of abreast seats, maximum seats, fuselage length, fuselage width, fineness ratio, tail section length, cockpit length and cargo compartment length are the main parameters studied about the fuselage design. Wing area, wingspan, aspect ratio, mean aerodynamic chord (MAC), taper ratio, dihedral angle, quarter chord sweep angle, and winglet lengths are the main parameters studied about the wing design. The area, span, aspect ratio, taper ratio, and quarter chord sweep angle of vertical and horizontal tail are the main parameters studied about the tail design. As a result of the study, exceptional designs and average design criteria for Airbus and Boeing aircraft have been revealed with the help of charts presented. In addition, the obtained linear correlations reveal that the MAC has about 0.14 times the wingspan and about 1.168 times the average chord length.

A key design parameter proposal for aerodynamically efficient subsonic blended wing body

PurposeBlended wing body (BWB) is a very advantageous design in terms of low fuel consumption, low emission and low noise levels. Because of these advantages, the BWB is a candidate to become the commercial passenger aircraft of the future by providing a paradigm shift in conventional designs. This paper aims to propose a key design parameter for wing sizing of subsonic BWB and a performance parameter for calculating the lift/drag ratio values of BWBs.Design/methodology/approachThe parameter proposed in the study is based on the square/cube law, that is, the idea that the wetted area is proportional to the power of 2/3 of the weight. Data on the weight, wing area, wingspan, lift-to-drag (L/D) ratio for 19 BWB used in the analyzes were compiled from the published literature and a theoretical methodology was developed to estimate the maximum lift to drag ratio of BWBs. The accuracy of the proposed key design parameter was questioned by comparing the estimated L/Dmax values with the actual values.FindingsIn the current study, it is claimed that the wingspan/(take-off gross weight)(1/3) parameter provides an L/D efficiency coefficient regardless of aircraft size. The proposed key design parameter is useful both for small-scale BWB, that is unmanned aerial vehicles BWB and for large-scale BWB designs. Therefore, the b/Wg(1/3) parameter offers a dimensionless L/D efficiency coefficient for BWB designs of different scales. The wetted aspect ratio explains how low aspect ratio (AR)-BWB designs can compete with high AR-tube-and-wing designs. The key parameter is also useful for getting an idea of good or bad BWB with design and performance data published in the literature. As a result, reducing the blending area and designing a smaller central body are typical features of aerodynamically efficient BWB.Originality/valueAs the role of the square/cube law in the conceptual aircraft design stage has not been sufficiently studied in the literature, the application of this law to BWBs, a new generation of designs, makes the study original. Estimation of the wetted area ratio using only wingspan and gross weight data is an alternative and practical method for assessing the aerodynamic performance of the BWB. According to the model proposed in the current study, reducing the take-off gross weight of the BWBs using lighter building materials and designing with a larger wingspan (b) are the main recommendations for an aerodynamically efficient BWB.

Wing shape differences along a migration route of the long-distance migrant Globe Skimmer DragonflyPantala flavescens

AbstractAnimals which migrate by flying should be subject to selection for optimal wing characteristics that maximize energy efficiency during migration. We investigated wing shape and wing area variation in the Globe Skimmer DragonflyPantala flavescens, which has the longest known migration of any insect. Wing shape and wing area differences between individuals in southern Peninsular India, and migrating individuals at a stop-over site on the Maldives, were compared. Results suggest that individuals which successfully reached the Maldives, on their way from India to Africa, had a broader wing base and an overall more slender wing shape than individuals in southern India. Contrary to our expectations, wing area did not differ significantly in most of our comparisons between southern India and the Maldives, suggesting that wing shape is more important than wing area for successful migration inP. flavescens. The results provide indirect evidence of natural selection on wing shape in a migrating dragonfly.

ДОСВІД І ОСОБЛИВОСТІ ФОРМУВАННЯ МАСОВИХ ХАРАКТЕРИСТИК МОДИФІКАЦІЙ ВАЖКОГО ТРАНСПОРТНОГО ЛІТАКА

Heavy transport aircraft are built and operated by US airlines (C-5A, C-5B, B-747-400), the European Concern Airbus (A-380), and the ANTONOV domestic state-owned enterprise. Such heavy aircraft as An-22, An-124 and An-225 have received worldwide recognition as the most efficient in their class [1, 2, 3]. It should be noted that such outstanding compatriots as O. K. Antonov, P. V. Balabuev, S. A. Bychkov, V. I. Tolmachev, V.F.Eroshin, O.K.Bogdanov made a decisive contribution to their improvement (including formation of mass characteristics).The main path of development of domestic heavy transport aircraft is to create modifications that meet the ever-increasing requirements of the time and customers to improve their transport and economic performance.The article shows that one of the ways to improve this type aircraft efficiency is the formation of their mass characteristics (i.e., mass of the aircraft modification itself and its individual units), which significantly affect all flight technical and economic parameters.It is proposed to take into account possible changes in four groups of parameters when assessing the starting mass (formed at the initial stages of creating a modification):T - a group of parameters that determine the level of requirements for a new modification;U - a group of parameters that determine the achievement of the stated goals at the stages of creation and operation of the modification;O - a group of parameters that determine the appearance of the future modification;P - a group of parameters that determine the mass and its density in the created modification.Division of the parameters into four groups makes it possible to evaluate and minimize the effect of the objective "square - cube" law on the mass gain in the design, production of a prototype and its flight tests and to represent it in the form of the starting mass of the modification (m0).The effectiveness of using the proposed approach to the formation of mass characteristics is shown on examples of the development of modifications of the An-124-100M and An-124-100M-150 airplanes.A distinctive feature of these modifications are: they were developed twenty years after creation of the base An-124 aircraft, carrying capacity has been increased by 30 tons, takeoff weight has been increased by 7%, the wing area, as well as the takeoff roll and landing run remained unchanged. The empty aircraft mass also remained unchanged, which indicates a special approach to the formation of mass characteristics. At the same time, in these modifications, the carrying capacity and flight performance increased by 25%, which is the highest achievement in the practice of creating aircraft of this type

Limitations and gaps in global bat wing morphology trait data

Abstract Species’ life‐history traits have a wide variety of applications in ecological and conservation research, particularly when assessing threats. The development and growth of global species’ trait databases are critical for improving trait‐based analyses; however, it is vital to understand the gaps and biases in the available data. We reviewed bat wing morphology data, specifically mass, wingspan, wing area, wing loading, and aspect ratio, to identify issues with data reporting and ambiguity. Additionally, we aimed to assess taxonomic and geographic biases in trait data coverage. We found that most studies used similar field methodology, but that data reporting and quality were inconsistent/poor. Additionally, we noted several issues regarding semantic ambiguity in trait definitions, specifically around what constitutes wing area. Globally, we found that bat wing morphology trait coverage was low. Only six bat families had ≥40% trait coverage, and, of those, none consisted of more than 11 species in total. We found similar biases in trait coverage across International Union for Conservation of Nature Red List categories, with threatened species having lower coverage. Geographically, North America, Europe, and the Indomalayan regions exhibited higher overall trait coverage, while both the Afrotropical and Neotropical ecoregions showed poor trait coverage. The underlying biases and gaps in bat wing morphology data have implications for researchers conducting global trait‐based assessments. Implementing imputation techniques may address missing data, but only for smaller regional subsets with substantial trait coverage. Due to generally low overall trait coverage, increasing species’ representation in the database should be prioritised. We suggest adopting an Ecological Trait Standard Vocabulary to reduce semantic ambiguity in bat wing morphology traits, to improve data compilation and clarity. Additionally, we advocate that researchers adopt an Open Science approach to facilitate the growth of a bat wing morphology trait database.

МЕТОД ВИЗНАЧЕННЯ ХАРАКТЕРИСТИК ЗАГАЛЬНОГО НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ В СИЛОВИХ ЕЛЕМЕНТАХ КОНСОЛІ КРИЛА ВІД НАВАНТАЖЕННЯ ФУНКЦІОНУВАННЯ

When the high - lift system are released, the aerodynamic flow around the wing changes significantly, which in turn leads to a change in the stress-strain state of the wing. This is due not only to an increase in lift due to a change in the curvature of the wing and an increase in the wing area, but also a change in the position of the center of pressure relative to the wing chord. A significant increase in torque leads to a change in the stress-strain state of the wing mean joints. An aerodynamic calculation was performed using ANSYS CFX to obtain the position of the point of action of the lift force in each elements of the wing (slat, wing box and flap). Were obtained the relative positions of the points of action of the lift of individual parts of the wing: the slat, the wing box and the flap. These values were used to apply the forces acting from the high - lift system. The distributed air load was proportionally distributed across the slat, wing box and flap in accordance with the obtained aerodynamic calculations using ANSYS CFX. Plots of internal force factors were plotted, such as a diagram of shear force, bending and torque for wing configurations without extended high - lift system, as well as with takeoff and landing positions of high - lift system. Obtaining the value of the internal force factors, were used to create calculation models. The structural elements of the wing, in particular the attachment points of the high - lift system, operate in a complexly stressed state. This complicates the process of predicting the fatigue life of these elements. To obtain a competitive aircraft, it is necessary to develop new methods of wing design with widespread use of integrated systems. The study of the change in the stress-strain state of the wing with the extended position of the high - lift system makes it possible to predict the fatigue life with high accuracy. The process of creating and preparing a wing model for calculation, setting boundary conditions and choosing the optimal size of a mesh element is described. Obtaining aerodynamic characteristics using a CAE system to create a design model.

Divergence in Body Mass, Wing Loading, and Population Structure Reveals Species-Specific and Potentially Adaptive Trait Variation Across Elevations in Montane Bumble Bees

AbstractBiogeographic clines in morphology along environmental gradients can illuminate forces influencing trait evolution within and between species. Latitude has long been studied as a driver of morphological clines, with a focus on body size and temperature. However, counteracting environmental pressures may impose constraints on body size. In montane landscapes, declines in air density with elevation can negatively impact flight performance in volant species, which may contribute to selection for reduced body mass despite declining temperatures. We examine morphology in two bumble bee (Hymenoptera: Apidae: Bombus Latreille) species, Bombus vancouverensis Cresson and Bombus vosnesenskii Radoszkowski, across mountainous regions of California, Oregon, and Washington, United States. We incorporate population genomic data to investigate the relationship between genomic ancestry and morphological divergence. We find that B. vancouverensis, which tends to be more specialized for high elevations, exhibits stronger spatial-environmental variation, being smaller in the southern and higher elevation parts of its range and having reduced wing loading (mass relative to wing area) at high elevations. Bombus vosnesenskii, which is more of an elevational generalist, has substantial trait variation, but spatial-environmental correlations are weak. Population structure is stronger in the smaller B. vancouverensis, and we find a significant association between elevation and wing loading after accounting for genetic structure, suggesting the possibility of local adaptation for this flight performance trait. Our findings suggest that some conflicting results for body size trends may stem from distinct environmental pressures that impact different aspects of bumble bee ecology, and that different species show different morphological clines in the same region.