Modern Wing Research Articles

Antwerp's Royal Museum of Fine Arts

AbstractThe Royal Museum of Fine Arts in Antwerp, Belgium, reopened after an 11‐year renovation. In addition to completely cleaning the exterior façade of the neoclassical building, a new, modern wing was built inside former internal courtyards—a glossy, white cube with very high ceilings and a dramatic 100+ step flight of stairs. The historical part of the museum was also fully renovated to its original grandeur. The collection was reinstalled, and the overall interpretive strategy focused on making the art approachable to a multigenerational and multicultural visitorship: Eschewing chronology, paintings are grouped by themes, texts are user‐friendly and encourage interactive experiences, and special activities are available for children. Short videos are also available in some galleries that provide context, explain specific art techniques, or contain games. A wide range of experiences is available to museum users, somewhat consistent with an approach proposed by the Smithsonian Institution's IPOP framework. The reviewer found the reinstallation and related user experiences a relevant, people‐oriented model for 21st century art museums.

Surface crack effect on frequency and vibration mode switching of solar-powered aerospace structures

In the engineering design of modern wing panels and their optimal control system, the first step is to find and predict their dynamic characteristics. These characteristics are dependent on material properties, panel geometry, and boundary conditions. In addition, possible fracture existence, imperfections and environmental conditions may unpredictably change the frequency and modes shape of the panel and then the parameters of a control system. In the present paper, the effect of surface fracture depth and orientation on frequency and vibration mode switching of perovskite solar cells-based aircraft wing panels is investigated for the first time. The PSC (perovskite solar cell) panel is made of a polymer substrate reinforced with even-distributed graphene platelets (GPLs) and thin solar layers to enhance the overall electromechanical performance of the whole structure. Equations of motion of the panel are obtained by the Hamilton approach based on the properties of Reddy's third-order shear deformation theory and linear components of the Green-Lagrange strain tensor. The novel aspect is a line-spring model of surface crack by Cartmell et al. adapted to the model of the PSC panel under consideration. The discretization of the established equations of motion for the cracked panel is carried out by the element-free IMLS-Ritz method with mesh-free features. Validation of the obtained solutions is carried out by comparisons with results from previous studies for cracked laminated plates.First, material and geometric properties effect on vibration characteristics of the PSC structure was investigated. Next, partial surface crack depth and orientation angle are examined to show changes in frequency and vibration modes shape of the panel. It is shown, that there is a mode swapping between the second and third modes when transitioning from an intact panel to a cracked one. As the crack length increases, higher-order mode variations become more noticeable, potentially leading to their swapping or the excitation of new ones. Additionally, the findings demonstrate that the surface crack orientation angle significantly impacts the higher-order modes of the panel. When the orientation angle is 90°, the first six modes align with those of the intact plate. Mode shapes and frequency shifts are significant for crack orientation angles between 0° and 90°.

Studying Forces on Three Different Designs of Formula 1 Front Wing

A simulation-based study of three different types of front wing designs used in the modern Formula 1 cars was done. The study mainly focuses on the aerodynamic forces that a Formula One car generates mainly the Downforce, the Drag force, & the Lateral force. These forces were studied in detail & taken a closer look at how do they migrate during the dynamic conditions the car is thrown into namely at various Ride Height changes, at various Side Slip (Yaw) Angles. A further elaborative study of the force builds up across the span of the wing was studied giving us a better picture of the concentration of the Downforce, drag force, & Lateral force being generated which will help us to correlate the pressure distribution data across the wingspan to the actual downforce concentration figures. A brief study of the flow field & flow lines was conducted along with the vortex generation for all three wings. A short comparison was made between the modern wing & a wing Ferrari used in the 1998 season, which will help us to understand the inherent problems that those designs had & how modern wings get around those.

МОДЕЛЮВАННЯ ВЗАЄМОДІЇ КРИЛЕВОГО ПРОФІЛЮ З ДОЩОВИМ ПОТОКОМ

The subject of the study is the analysis of the multilateral impact of rainfall on the flight of a modern aircraft. When considering various factors of this impact, it was found that the main negative consequences of the interaction of the aircraft with the rain flow are the formation of a thin layer of water on its surface, which under the influence of drops and surface tension forces changes the configuration of the wing profile, causing loss of load-bearing properties and an increase in frontal aircraft resistance. The influence of rain flowing around the bearing surfaces can be reduced to taking into account changes in the characteristics of the surface and the flow of the airflow. The goal is to develop a model for the interaction of modern wing profiles with rain flow. The task is to determine the amount of water deposited on the surface of the wing profile, calculate the parameters of the water film formed on its surface, and as a result of this, change the tangential stress at the liquid-air interface. The semi-empirical calculation method used reveals a significant dependence of the amount of precipitated rain water on the surface of modern wing profiles on their geometry and the conditions of interaction with the stream of raindrops. The result of this work is the resulting model, which allows you to simulate the flow conditions around the wing profile in the rain stream and evaluate the relationship of rain intensity with the parameters of the water film that forms on the profile. Conclusions. An analysis of the features of the rain film flow over the surface of the wing profile and its effect on the parameters of the boundary layer shows the negative nature of the effect of rainfall on the aerodynamics of the aircraft. The results obtained allow us to judge the reliability of using the adopted model to calculate the effect of rain on the aerodynamic characteristics of wing profiles, and the possibility of using the results to determine the dependence of the aerodynamic characteristics of wing profiles on the conditions of rainfall molasses.

Global instability of wing shock-buffet onset

Shock buffet on wings encountered in edge-of-the-envelope transonic flight remains an unresolved and disputed flow phenomenon, challenging both fundamental fluid mechanics and applied aircraft aerodynamics. Its dynamics is revealed through the interaction of spanwise shock-wave oscillations and intermittent turbulent boundary-layer separation. Resulting unsteady aerodynamic loads, and their mutual working with the flexible aircraft structure, need to be accounted for in establishing the safe flight envelope. The question of global instability leading to this flow unsteadiness is addressed herein. It is shown for the first time on an industrially relevant configuration that the dynamics of a single unstable oscillatory eigenmode plays a prominent role in near-onset shock buffet on a quasi-rigid wing. Its three-dimensional spatial structure, previously inferred both from experiment and time-marching simulation, describes a spanwise-localised pocket of shear-layer pulsation synchronised with an outboard-propagating shock oscillation. The results also suggest that the concept of a critical global shock-buffet mode commonly reported for two-dimensional aerofoils also applies to three-dimensional finite and swept wings, albeit different modes at play. Specifically, the modern wing design, NASA Common Research Model, with publicly available geometry and experimental data for code validation is studied at a free-stream Mach number of 0.85 with Reynolds number per reference chord of and varying angle of attack between 3. 5° and 4. 0° targeting the instability onset. Strouhal number at instability onset just above 3. 7° is approximately 0.39. At the same time, a band of eigenmodes shows reduced decay rate in the Strouhal-number range of 0.3 to 0.7, with additional unstable oscillatory modes appearing beyond onset. Importantly, those emerging modes seem to discretise the continuous band of medium-wavelength modes, as recently reported for infinite swept wings using stability analysis, hence generalising those findings to finite wings. Through conventional time-marching unsteady simulation it is explored how the critical linear eigenmode feeds into the nonlinearly saturated limit-cycle oscillation near instability onset. The established numerical strategy, using an iterative inner–outer Krylov approach with shift-and-invert spectral transformation and sparse iterative linear solver, to solve the arising large-scale eigenvalue problem with an industrial Reynolds-averaged Navier–Stokes flow solver means that such a practical non-canonical test case at a high-Reynolds-number condition can be investigated. The numerical findings can potentially be exploited for more effective unsteady flow analysis in future wing design and inform routes to flow control and model reduction.

A Bird's Eye View: Hesperornithiforms as Environmental Indicators in the Late Cretaceous Western Interior Seaway

Seabirds are considered indicators of ecological hotspots in modern ecosystems because their biogeographic distribution is correlated with physical, chemical, and biological oceanographic factors. Pursuit diving seabirds – those that actively pursue prey underwater – are generally more limited in distribution and more closely tied to oceanographic factors, as diving ability is often gained at the expense of flight capabilities. Today, wing propelled pursuit diving seabirds are restricted to colder waters; foot propelled divers have a broader latitudinal distribution, but do not forage far from shore in marine environments. In comparison, Late Cretaceous Northern Hemisphere seas were host to foot propelled pursuit diving seabirds called hesperornithiforms. Their Western Interior Seaway fossil record, in particular, reflects the broad latitudinal distribution of modern foot propelled divers, but with occurrences of offshore foraging more typical of modern wing propelled divers. The presence of hesperornithiforms in such a wide variety of environments (Boreal, Tethyan, coastal, nearshore, and offshore) suggests different ecological and oceanographic conditions affected biogeographic patterns of Late Cretaceous divers. The purpose of this study is to explore Late Cretaceous hesperornithiform paleobiogeography in light of what is known about how biotic and environmental factors affect modern pursuit diving seabirds to better understand WIS paleoecology.The Late Cretaceous was characterized by greenhouse climate, high sea levels, and epicontinental seas that provided marine paleoenvironments with no modern analogs. Two notable ecological differences between the Late Cretaceous and today are the presence of marine reptiles (and absence of marine mammals) as apex predators and the lack of acanthomorph fish diversity. Spatio-temporal overlap among hesperornithiforms, marine reptiles, and large predatory fishes implies different competition and predator-prey relationships among marine carnivores than today. Differences in swimming capabilities between marine reptiles and marine mammals may partially account for the presence of hesperornithiforms in warm, offshore waters. Additionally, environmental factors relating to the unique paleoceanography of the WIS would have also influenced hesperornithiform populations. Ample shoreline, abundant shallow water habitats, and high primary production made epicontinental seas hotspots for pursuit diving seabirds, despite warmer temperatures. Together, ecosystem structure and the unique oceanographic factors characterizing epicontinental seas both contribute to differences in seabird biogeography between the Late Cretaceous and today.

The tail end of hummingbird evolution: parallel flight system development in living and ancient birds

Evolutionary innovations are central to debates about biological uniformitarianism because their very novelty implies a distinct evolutionary dynamic. Traditional scenarios for innovations in the development of avian powered flight exemplify the kinds of distinctions considered to occur at different times during the history of innovations. Thus, the progressive change of the wing stroke mechanism early in its evolution is considered to have imposed strong functional and historical constraints on tail shape diversity, whereas attainment of the modern flight stroke mechanism is considered to have liberated the tail to radiate into a wide variety of other functions and forms. Detailed analyses of living hummingbirds revealed that these highly aerial birds actually expressed many parallel functional constraints and historically progressive patterns observed earlier in avian history: (1) more basal lineages had relatively weak wing muscles (patagial muscles and tendons, TPB), convex to square tails, and more linear flight employed in nonterritorial foraging; (2) more derived lineages had a stronger TPB, forked tails, accentuated growth of tail fork, and more manoeuvrable and agile flight employed in territorial foraging; and (3) the most derived lineage had the strongest TPB, greatly reduced tails, and mainly bee-like flight. These associations make functional sense because convex tails increase stability and efficiency in linear flight, concave tails augment lift for turning flight in territorial defence, and tails become aerodynamically disadvantageous if the wings provide sufficient lift. Derived hummingbird lineages also demonstrated the same expansion of tail shape and taxonomic diversity associated with perfection of the modern wing stroke mechanism earlier in avian history. Thus, living hummingbirds are a microcosm of overall avian flight evolution. Other living avian (‘aerial courser') and extinct reptilian (Pterosaur) clades with extraordinary flight abilities provide evidence for similar patterns, suggesting a broadly defined uniformitarianism (early constraint followed by later radiation) at the limits of the flight performance envelope throughout vertebrate history. Correlated evolution of TPB and tail form suggests that natural selection on an integrated flight system was the principal mechanism fostering the avian patterns, although strengthening of wing muscles in derived lineages may have facilitated expansion of caudal morphological diversity through a balance between natural and sexual selection on males. These findings suggest that wing muscles, locomotor integration, and phylogenetic patterns are essential for understanding function and adaptation of tails in living as well as ancient birds. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 467–493.

Wing aerodynamics and the science of compromise

AbstractFrom Lanchester to the A380; from the era of the great pioneers to the integrated engineering teams and sophisticated analyses required to develop todays airliner. The ‘art’ of Aerodynamics has progressed a long, long way in the intervening century, but even with todays computational power it is still relevant to understand the basics and the early theories as developed by Lanchester and his contemporaries. In this lecture, the relevance of some of that early work and the compromises that must be made in optimising a modern wing design will be presented. These will include optimisation of spanwise loading, including trimming effects and winglets, and high and low speed aerodynamic and structural interactions, with examples drawn from the author's career in helping to develop the wings for the HS146 (now the RJX) and the Airbus family.With the exponentially increasing computer power available over the last 30 years, the ‘art of compromise’ has progressively become the ‘science of optimisation’ and the lecture closes with a brief reference to techniques used to optimise current wing designs for the Airbus family.

The pioneers of flight: a documentary history

pioneers of flight left a legacy of inventions that changed the world. Unknown to most people, many also left compelling written accounts of their ideas, scientific discoveries, and attempts--both successful and disastrous--to take to the air. Phil Scott presents the first major anthology of these writings. His selections show how humans from Ovid to the Wright brothers and beyond dreamed about flying and puzzled over the principles of physics and aerodynamics that kept birds aloft and men grounded. Their eloquent and incisive writings form a record of scientific curiosity and individual tenacity that will fascinate aviation enthusiasts, historians of technology, and anyone interested in the drama of early flight.Scott begins with Ovid's story of Icarus, who met his legendary fate by flying too close to the sun and melting the wax that held his wings together. He presents accounts of crude medieval experiments and the beginnings of a scientific approach to flight in Renaissance and early modern Italy. He includes a letter from the Marquis d'Arlandes about being aboard the Montgolfiers' famous balloon for the first ever manned flight. book's main focus, however, is the development of airplanes in the nineteenth and early twentieth centuries. Scott presents scientific notes, letters, patent applications, fund-raising proposals, newspaper reports, journal articles, and personal stories by or about such central figures as Sir George Cayley, John Stringfellow, Otto Lilienthal, Clement Ader, Octave Chanute, Louis Bleriot, Glenn Curtiss, and, in particular, the Wright brothers. We read about the insights that led to propellers and to the shape of the modern wing, the frustrations and dangers of attempting flight, the Wrights' revolutionary technological innovations and their brilliant successes at Kitty Hawk, technical and commercial disputes, and the experiences of early women aviators and the adventurers who made the first long-distance flights.Scott includes an extensive introduction that puts the selections in the context of aeronautical history. The Pioneers of Flight is a remarkable resource for anyone who wishes to understand how humans struggled and eventually learned to fly.

Modern wing flutter analysis by computational fluid dynamics methods

The application and assessment of the recently developed CAP-TSD transonic small-disturbance code for flutter prediction is described. The CAP-TSD code has been developed for aeroelastic analysis of complete aircraft configurations and was previously applied to the calculation of steady and unsteady pressures with favorable results. Generalized aerodynamic forces and flutter characteristics are calculated and compared with linear theory results and with experimental data for a 45 deg sweptback wing. These results are in good agreement with the experimental flutter data which is the first step toward validating CAP-TSD for general transonic aeroelastic applications. The paper presents these results and comparisons along with general remarks regarding modern wing flutter analysis by computational fluid dynamics methods.

Modern Wing Shapes

IT is not only feminine attire that is subject to the vagaries of fashion. Anyone who has watched the evolution of the aeroplane over any considerable period of time will have noticed how subject it also is to the dictates of Fashion's decrees. Springing up from no one quite knows where, one suddenly becomes conscious that there has been a subtle change in the appearance of the aeroplanes seen about. There are always, of course, a few “ frumps ” whose type remains readily recognisable owing to its resemblance to its parents and ancestors. But it is none the less the fact that at any given period the bulk of the aeroplanes of the day have a similarity of appearance. This is indeed a constantly recurring pitfall for the enthusiast who for one reason or another does not have the opportunity of making very frequent visits to an aerodrome. On one of the rare occasions when he makes his presence felt he is apt to incur the contempt of his more knowledgeable colleagues by an unfortunate propensity for confusing the aeroplanes produced by the designers of different, and perhaps closely rival, firms. The position in this respect seems to get worse. Twenty‐five years ago no one but the veriest ignoramus could mistake a Blriot, say, for a Farman or an Antoinette. Nowadays, however, it is comparatively easy— or so we confess we find it—to be confused about the make of half a dozen different types of aeroplane. A few years ago it still remained easy at any rate to segregate machines by the eye into their respective classes. There was a stateliness, possibly even a suspicion of clumsiness, about a bomber which distinguished it instantly from a fighter. But even this superficial distinction is nowadays denied to those unfortunates of whom we write.

Aerodynamic Theory of To‐day

THE science of aerodynamics has made rapid progress during the last ten or twenty years, and the rate of advance shows little sign of abating. Text books, however, are as yet few in number, and these two books, though differing widely in character, are both welcome additions to our literature. Prof. Pistolesi's “Aerodinamica” is a comprehensive account of the present state of aerodynamic theory, which will be of great value to advanced students of the subject and, more generally, as a standard book of reference. It includes full accounts of the modern aerodynamic theories of wings and airscrews and of the progress in the analyses of the motion of viscous and compressible fluids, together with detailed references to original papers on these subjects. Prof. Reid's aim is more modest in scope, but no easier of execution. He has endeavoured to provide an account of modern wing theory suitable for engineering students and aeroplane designers of limited mathematical knowledge, and he has fulfilled his object by combining a detailed development of the more elementary parts of the subject with a descriptive and critical account of the more complex parts.