Side Of Wing Research Articles

Melanism and color saturation of butterfly assemblages: A comparison between a tropical rainforest and a xeric white forest

The study of butterfly coloration has helped to identify the ecological pressures involved in the evolution of animal coloration. However, almost all studies that addressed this issue have focused on species that inhabit more temperate environments, leaving the species and ecological factors of tropical regions mostly understudied. Here, our purpose was to evaluate whether butterfly assemblages from two distinct Neotropical biomes (i.e., tropical rainforest and xeric white forest) differ regarding their melanism and/or color saturation. Our hypotheses were that (1) tropical rainforest butterflies should be more melanic and color saturated, and that (2) butterflies from more open/arid tropical environments should be more melanic on their dorsal wing surfaces than on their ventral wings. Therefore, we quantified melanism and color saturation from dorsal and ventral surfaces of 121 different butterfly species. Comparisons show that rainforest butterflies, when contrasted to white forest butterflies, have more melanic dorsal wing surfaces, which might be seen as a form of protection against parasites. Our data also show that rainforest butterflies, but not white forest species, have darker dorsal wing surfaces, when compared to their own ventral surfaces, a trend that was also found for species inhabiting both biomes, which might be associated to thermoregulatory advantages. At last, our results also point that butterflies' dorsal wing sides present a higher variance between species (regardless of Biome), when compared to their own ventral wing side, an indication that some ecological factor (e.g., predation avoidance) might be exerting a strong homogenizing force on ventral wing coloration.

Innovative liner concept using friction powder for increasing of broadband noise absorption. Applications for broadband noise absorption in fan duct

This paper presents research related influence of friction powders on enlarging the absorption band of acoustic liners used for reduction of tonal noise in fan duct of aero-engine. Kundt tube measurements done at COMOTI using fine powders (granules) made of various light-weight materials placed in the honeycomb cells of SDOF liners have shown a considerable broadening of the absorbed band of frequencies without a significant decreasing of absorption at the resonance frequency. Although the phenomenon is generally present for any type of powder, it was observed that for some powders the absorption is higher than for others. On the other hand, it was observed that the effect of the filling percentage of the cavity is important. Then, experiments done at the grazing flow facility of CNRS-Le Mans University have shown that the phenomenon is also present for high acoustic incident levels (up to 140dB) and M=0.13 while it still depends by the nature of powder material. The best results were obtained for the cork powder when the honeycomb is filled with powder at 66% of its height. For this material, the broadening of the transmission loss well was maximum. This phenomenon could be explained by the apparition of friction between powder granules which are taking place at very low scale consuming the noise power on a broader range of frequencies. It is supposed that the friction between the particles of powder have major influence because the best noise absorption was obtained for powders with a large distribution of particles’ dimensions while for particles with a small dimensional distribution (expanded polyester balls, for example) the transmission well broadening was smaller. The friction powders technology is simple and can be easily adapted to existing acoustic liner technologies with small manufacturing costs. This feature is conferred by the fact that powders can be easily poured in the honeycombs at the required height. The friction powder technology can be applied not only for the fan duct. In future, it could also be applied for reduction of jet noise reflected by pressure side of wing and for cabin noise reduction.

Low speed lateral-directional dynamic stability analysis of a hypersonic waverider using unsteady Reynolds averaged Navier Stokes forced oscillation simulations

Hypersonic waveriders have the potential to significantly reduce travel times on long haul civilian transport routes. The design of hypersonic aircraft is heavily influenced by the aerodynamic efficiency at the cruise Mach number, resulting in less than ideal geometries for subsonic flight. Waverider aerodynamics and stability in the low speed regime is rarely investigated and not well understood, but is crucial for horizontal take-offs and landings. To date, low speed analyses of waverider shapes have been confined to static investigations, with limited work on longitudinal dynamics. No studies outlining the lateral-directional dynamic stability and aerodynamic derivatives has ever been published. This paper presents results for the low speed propelled variant of the Mach 8 HEXAFLY-INT waverider, which was subjected to forced oscillations in roll, yaw and side-to-side translations. This was achieved using unsteady Reynolds Averaged Navier Stokes simulations. Tests were conducted at a speed of 20 m/s, which correlates to a Reynolds number of approximately 1.5×106. The dynamic motion was at a forced frequency of 1 Hz with angle amplitudes of 1 degree. The vehicle was analysed through an angle of attack range from -5 to 15 degrees in 5 degree increments. Results for the nominal centre of gravity location at 44.4% of the vehicle length show values for the dynamic derivatives within expected ranges, apart from the rolling moment due to yaw rate below approximately 2 degrees angle of attack. A similar finding for the dihedral derivative in static tests concluded that the low mounted wing with anhedral results in instabilities at low angles of attack. Investigations conducted at a centre of gravity location of 53.1% of the vehicle length, the aft static stability limit, also showed data within normal ranges. For these cases, the derivative magnitudes were lower, which indicates decreased damping compared to the nominal centre of gravity location. Some significant impact was seen on the roll damping derivative due to lowering the centre of gravity. This is from a combination of non-linear wing side force variance with angle of attack and the reduction of the moment arm, which resulted in less damping. The derivatives generally showed little sensitivity to changes in the oscillation frequency, with frequency rates ranging from 0.5 to 2 Hz tested. Overall, the results from this study highlighted the complex combinations of rate induced forces which contribute to the dynamic behaviour of the aircraft.

Modeling and Investigations on Surface Colors of Wings on the Performance of Albatross-Inspired Mars Drones and Thermoelectric Generation Capabilities

Thermal effects of wing color for Albatross-inspired drones performing in the Martian atmosphere are investigated during the summer and winter seasons. This study focuses on two useful consequences of the thermal effects of wing color: the drag reduction and the thermoelectric generation of power. According to its color, each wing side has a certain temperature affecting the drag. Investigations of various configurations have shown that the thermal effect on the wing boundary layer skin drag is insignificant because of the low atmospheric pressure. However, the total drag varies as much as 12.8% between the highest performing wing color configuration and the lowest performing configuration. Additionally, the large temperature differences between the top and the bottom wing surfaces show great potential for thermoelectric power generation. The maximum temperature differences between the top and bottom surfaces for the summer and winter seasons are, respectively, 65 K and 30 K. The drag reduction and the power generation via thermoelectric generators both contribute to enhancing the endurance of drones. Future drone designs will benefit from increased endurance through optimizing the wing color configuration.

Identifikasi Kupu-Kupu Menggunakan Ekstraksi Fitur Deteksi Tepi (Edge Detection) dan Klasifikasi K-Nearest Neighbor (KNN)

Lampung has the only breeding of in situ butterflies engineered in Indonesia namely Gita Persada Butterfly Park, which has approximately 211 butterfly species. Butterflies can be classified according to patterns found on the wings of a butterfly. The weakness of the human eye in distinguishing patterns on butterflies is a foundation in building butterfly identification based on pattern recognition. This study uses 6 species of butterflies: Papilio memnon, Troides helena, Papilio nephelus, Cethosia penthesilea, Papilio peranthus, and Pachliopta aristolochiae. The butterfly dataset used is 600 images. The butterfly image used is in the form of the upper wing side. The pre-processing stage uses the method of scaling, segmentation, and grayscale. The feature extraction stage uses the canny edge detection method by applying smoothing, edge strength, edge direction, non maximum suppression, and hyterisis thresholding. The classification phase uses the K-Nearest Neighbor (KNN) method with values k = 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 and 23 obtained under the Rule of Thumb. The identification of butterfly require a classification time of 8 seconds. The highest accuracy is obtained from testing with a value of k = 5 by 80%.

Control device effectiveness studies of a 53∘ swept flying wing configuration. Experimental, computational, and modeling considerations

The present investigation covers studies of different control devices on several 53∘ swept flying wing configurations without a vertical tail plane. The wings considered share the same planform but differ in their spanwise profile shapes. The planform, developed under the NATO AVT-251 Task Group, is referred to as the MULDICON (or MULti-DIsciplinary CONfiguration). The objectives of this article are twofold: (1) to design yaw control surfaces for the MULDICON wing using an experimental/computational approach and (2) to develop aerodynamic models that rapidly and accurately predict the effectiveness of control surfaces over a wide range of flight conditions. The yaw control surface design (position and size) should provide sufficient yaw moment with almost no contribution in roll and pitch moment. To identify such concepts, a number of preliminary experiments on a generic flying wing configuration have been conducted. Two promising concepts from wind tunnel tests were then numerically examined for being implemented in the MULDICON baseline wing. Concepts with spoilers and a split flap were specifically considered. For medium to high angles of attack, the flow topology of the baseline wing is dominated by a vortical flow field on the upper outer wing. This leads to interactions between vortex and the control device which influences the flow and the attitude of the control device on the upper wing side. Furthermore, this work considers developing aerodynamic models for predicting stability derivatives of several MULDICON designs over a wide range of flight conditions. Aerodynamic loads models are only developed for normal force and pitch moment coefficients, however, the developed approach can easily being extended to include lateral aerodynamic coefficients as well. Quasi-steady models of this work are power series expansions of traditional linear aerodynamic models to capture nonlinear effects. Additionally, the models can estimate static and dynamic stability derivatives and the control surface powers.

Flight mechanics model for spanwise lift and rolling moment distributions of a segmented active high-lift wing

In this study, the aerodynamics of wings using an active high-lift system are investigated. The target is the flight mechanical description of the spanwise forces and resulting moments and the influence of the active high-lift system to their distribution. The high-lift system is a blown flap system divided into six segments per wing. Each segment is assumed to be individually controlled, so the system shall be used for aircraft control and system failure management. This work presents a flight mechanical sub-model for the simulation of flight dynamics, which has been derived from high-fidelity CFD results. An assessment of single-segment blowing system failures will be presented including recommendations for compensation of either lift or rolling moment loss. For this investigation, the compensation is required to act at the same wing side on which the failure appears. Thus, the potential for an increase of system reliability shall be proven. The results show that less performance investment in terms of pressurized air is necessary to compensate the rolling moment of a failing segment instead of its lift. However, large blowing performance increases for the remaining wing segments that occur for some of the failure cases.

Long-term durability of superhydrophobic properties of butterfly wing scales after continuous contact with water

Nature has always provided a lot of inspirations for engineers and scientists. The butterfly wing is a kind of typical surface that performs excellent properties of superhydrophobicity especially for the front side of the wings. However, in this work, it was interestingly found that the back side of butterfly Papilio ulysses wings exhibits a better long-term durability of superhydrophobic properties under water than the front side of the wing. In the process of the experiment, both sides of butterfly wings were soaked under the deionized water within 60h and measured the changes of the contact angle (CA) at regular intervals. It was discovered that the back side of butterfly Papilio ulysses wings shows stronger hydrophobicity under continuous contact with water. In contrast, the front side of the wings was obviously somewhat “poorly” in the aspect of superhydrophobicity after a long soak underwater. Then, the optimized 3D configurations of the coupling structures were determined by using the Field Emission Scanning Electron Microscope (FESEM). It was found that there are so much little hairs on and between the scales on the back side, which don’t existed on the front side of the wings. At last, the underwater superhydrophobic mechanism of the back side of butterfly wing scales was revealed. In fact, the strong superhydrophobicity underwater of the back side of butterfly wings should be owing to its special surface structures. The hairs between scales on back side of butterfly wings could prevent the liquid from moving down rapidly underwater. When it reached the new balance, the forces will form the second balance and the liquid level advanced slowly very much. So, the back side of butterfly wing exhibits a better long-term durability of superhydrophobic properties under water than the front side of the wings. If this functional “biomimetic structure” could be applied on metal surface, it would be potential not only to the passive drag reduction but also to preventing bacteria from adhesion to the ships or other aquatic vessels.

The function of resilin in honeybee wings

The present work aimed to reveal morphological characteristics of worker honeybee (Apis mellifera) wings and demonstrate the function of resilin on camber changes during flapping flight. Detailed morphological investigation of the wings showed that different surface characteristics appear on the dorsal and ventral side of the honeybee wings and the linking structure connecting the forewing and hindwing plays an indispensable role in honeybee flapping flight. Resilin stripes were found on both the dorsal and ventral side of the wings, and resilin patches mostly existed on the ventral side. On the basis of resilin distribution, five flexion lines and three cambered types around the lines of passive deformation of the coupled-wing profile were obtained, which defined the deformation mechanism of the wing along the chord, i.e. concave, flat plate and convex. From a movie obtained using high-speed photography from three orthogonal views of free flight in honeybees, periodic changes of the coupled-wing profile were acquired and further demonstrated that the deformation mechanism is a fundamental property for variable deformed shapes of the wing profile during flapping flight, and, in particular, the flat wing profile achieves a nice transition between downstrokes and upstrokes.

Fabrication of Comb Shape of Leading Edge Wing of Dragonfly

Research on Micro air vehicle (MAV) has been carried out by many researchers to gather information in environmental monitoring, security and so on. When the earthquake, fire, smoke take place, it is difficult for human beings to investigate the detail because of dangerous condition. However, MAV has possibility to investigate the detail because MAV can fly freely around. Recently, dragonfly is highly focused by many researchers because dragonfly has high flight performances those are high efficiency flight, unintended acceleration, rapid turn and hovering. In general, these characteristics have root that wing is corrugation shape. We focus on microstructures on wing and its aerodynamic characteristics because there are many unique microstructures. We focused on micro spikes on dragonfly wing. Over three thousands of spikes exist on two sides of wing. The length and shape of spikes are 10 to 100 micron meters and oblique circular cone. It is important to clear the aerodynamic effect of the oblique circular cone. Artificial wing was fabricated by following processes. We fabricated micro spikes utilizing electro polishing. Fabricated micro spikes were set on plate utilizing micro spot bonding. We investigated the flow around the artificial wing and found that the flow around wing was controlled by micro spikes on wing. In this paper, we focused on comb shape of leading edge of wing. Comb shape is fabricated utilizing micro-EDM. We investigate flow characteristics of comb shape.

Flow topology around a simplified two-wheel landing gear

Flow topology around a simplified model of a two-wheel landing gear is studied using the hydrogen-bubble visualization technique. The complete test model consists of two wheels, an axle, a main strut and a support strut. A number of wheel models with varying geometric details are considered. During the analyses, the flow field around the wheels is divided into three main regions: upper, central and lower. (1) In the upper (wing side) flow region, the flow along the inner side surface of the wheels either remains attached until the wheel aft or it separates prematurely and periodically forms slant vortices in the near wake. The wheel geometry is found to control the type of separation. (2) In the central flow region, comparison of the flow sections above and below the axle shows that main strut blockage has a significant influence on the separation behavior of the flow between the wheels. Furthermore, the addition of interior wells to the wheel geometry is found to result in a cross-stream jet at the level of the axle. This highly-erratic fluid ejection has the potential to be a source of aeroacoustic noise. (3) In the lower (ground side) flow region, the near wake is shown to accommodate periodically forming large-scale structures.

Independent components of wing kinematics in the fruit fly Drosophila

Flies are known for their supreme flight maneuverability that is facilitated by their highly specialized flight apparatus. While large power muscles generate the basic wingbeat, flies control their flight with about 6 miniscule steering muscles per wing side. It is thought that a small number of steering muscle co-activation synergies give rise to the fast and precise changes in wingbeat responsible for flight maneuvers [1]. Complementary to existing electrophysiological studies of selected muscles, we developed a statistical method based on independent component analysis [2] to classify the wing stroke patterns of the fruit fly. Our method identifies components of the wing motion that are maximally statistically independent of each other; such components may be viewed as manifestations of basic neuromotor flight control modes resulting from specific muscle synergies. We recorded the wing motion of tethered flying fruit flies using a high speed computer vision system together with a novel procedure for online extraction of wing position (TrackFast, SciTrackS.com) [3]. This setup enables a continuous recording of 10 000 wingbeat cycles at a rate of 6000 Hz (~16 data points / cycle); such long duration recordings permit statistical analysis. We defined stroke angles at 8 distinct phases of the wingbeat cycle as separate time series, and thus each test flight was represented by a set of 16 signals (both wings). For the ICA analysis we used the MILCA algorithm [1] and judged its success by estimating pairwise mutual information of the least dependent components (LDCs) obtained. Based on the power spectral densities of the obtained LDCs, we separated random changes in wing trajectory from variations reflecting possible flight maneuvers. Among the components with significant temporal structure, we identified 7 distinct types of LDCs, of which three are related to well-known flight maneuvers. To interpret the corresponding stroke modifications, we reconstructed the stroke trajectories by inverse transforming LDCs such that the variance of all but that of the one of interest is suppressed. In some instances our MILCA analysis resolved complex trajectory variations into simpler events characteristic of LDCs (Figure ​(Figure1).1). This implies that muscle synergies separated in individual LDCs linearly superpose when acting simultaneously. In conclusion, our findings suggest that a limited number of independent control modes are active during a given flight test and that the muscle synergies corresponding to these modes operate nearly independently from each other. Figure 1 A) Time course of two LDCs from a flight segment of 2000 wingbeat cycles. B) Recorded stroke trajectories of 10 cycles (highlighted in A). Red: left wing; blue: right wing. Black line shows mean trajectory during the whole flight segment. C, D) Reconstructed ...

Four coordination clusters using fluorenyl and carbazyl phosphonates as ligands

Four polynuclear complexes, [Co4(FluPO3)2(FluPO3H)2(CH3CO2)2(py)6(H2O)2] (1), [Mn5O3(FluPO3)2(PhCO2)5(CH3OH)(phen)2] (2), [Mn5O3(CarbPO3)2(PhCO2)5(CH3OH)(phen)2] (3) and [MnII4MnIII6O2(OH)2(CarbPO3)8(PhCO2)4(py)6] (4) (FluPO3H2 = (9-methyl-9H-fluoren-9-yl)phosphonic acid, CarbPO3H2 = N-carbazolylmethylphosphonic acid), were synthesized and characterized. In compound 1, the cobalt centers are bridged by phosphonate ligands into a circle. Both the cores of complexes 2 and 3 feature three μ3-O and two capping FluPO32− or CarbPO32− groups bridging five MnIII atoms to form a basket-like cage structure. Complex 4 contains divalent and trivalent ions and has a butterfly-like [MnII4MnIII6O2(OH)2(CarbPO3)4]12+ core with four phosphonate ligands in the body position and five Mn atoms on each wing side. Magnetic susceptibility measurements reveal the existence of antiferromagnetic interactions in 1, 2·4CH3CN·2H2O, 3·PhCO2H·6CH3CN·2H2O and 4·py·8H2O. Fitting the experimental data led to the following parameters: J1 = −10.1 cm−1, J2 = −18.0 cm−1, J3 = −8.0 cm−1, J4 = −5.9 cm−1, J5 = −2.8 cm−1, g = 2.0 for 2·4CH3CN·2H2O, and J1 = −7.4 cm−1, J2 = −22.8 cm−1, J3 = −6.9 cm−1, J4 = −4.8 cm−1, J5 = −0.3 cm−1, g = 2.0 for 3·PhCO2H·6CH3CN·2H2O.

Wing feather moult and age determination of Snowy Owls Bubo scandiacus

Moult of primary and secondary flight feathers of Snowy Owls Bubo scandiacus was studied from 53 museum specimens retaining some juvenile feathers. There were no ringed Snowy Owls of known age in the skin material, and the moult pattern has thus been interpreted using the moult of Eagle Owls Bubo bubo as a model. The difference between juvenile and adult primaries is described. Greater coverts may facilitate age determination of single flight feathers. Snowy Owls start their first flight feather moult M1 by shedding the innermost 2-6 secondaries during their second summer (as 2C birds). A majority of the owls also shed primary P7 during this first moult, occasionally also P8. This moult progresses at a faster pace than seen in Scandinavian Eagle Owls. During their second flight feather moult M2, moult of secondaries advances outwards, including moult from the two focal points S2 and S5, as in the Eagle Owl. Both P7 and P8 are moulted and fresh after M2, and some owls even moult P6 or P9. After the third flight feather moult M3 it is very hard to distinguish juvenile secondaries from old M1 secondaries, and a specific moult pattern is most easily recognized in primaries. On sharp images of the upper side of wings on a flying Snowy Owl, or on birds in hand, it should be possible to age birds up to four calendar years (4C) in autumn and five calendar years (5C) in spring, before onset of the fourth flight feather moult M4.

Experimental Studies on a Rudimentary Four-Wheel Landing Gear

Experiments were carried out on a rudimentary four-wheel landing-gear arrangement to understand the flow physics of this configuration. Measurements carried out included oil-flow visualization, steady surface pressures and two-dimensional particle image velocimetry measurements in the near wake at a Reynolds number based on wheel diameter of 1 � 106. The surface visualization demonstrated the significantly asymmetric behavior of the flow on both the front and back wheel. The surface-pressure data show that separation is earlier on the wing side as opposed to the ground side for both wheels, caused by the presence of the vertical strut. The data show that the truck and strut are dominant contributors to the total drag. The off-body measurements in the near wake document the confluent wakes from the wheel and the horizontal strut leading to a three-dimensional unsteady wake. The data presented here provide a comprehensive picture, both quantitatively and qualitatively, of the flow over a rudimentary landing gear and are useful for validation of computational fluid dynamics efforts in addition to understanding the flow physics of such configurations.

Effect of bird geometry and orientation on bird-target impact analysis using SPH method

In this study, a real mallard anatomy is numerically created from CT images and then analysed by SPH method. The result produced by the real bird is compared to that of the traditional bird models. The effects of considering the cavities, air and different orientations at which a mallard strikes a target are also investigated. In order to study the effect of orientation of bird on bird-strike events, four impact scenarios were considered and simulated: the impact from bottom, head, tail and wing sides. It was found that the impact from the bottom side is the most damaging scenario, while the impact from the wing side is the safest impact scenario. Distribution of peak and stagnation pressures, impulse transferred to the target and pressure profile for each impact scenario have also been discussed and analysed.

Does isolation affect phenotypic variability and fluctuating asymmetry in the endangered Red Apollo?

Isolated populations represent one of the main focuses in conservation biology. Long-term isolation often causes losses of genetic diversity and as a consequence might reduce individual fitness. Morphometric characters can be used as suitable markers to analyse ecological stress and individual fitness of local populations. Asymmetry in bilateral symmetry is used as a measure for developmental instability of populations and is often negatively correlated with population size and low genetic diversity. As a study system, we selected the endangered butterfly Parnassius apollo, which occurs in small and isolated remnant populations in Central Europe, but also in fairly large metapopulations in the Alps. We analysed wing morphometrics (shape and size characters) of 812 individuals representing (1) already extinct, (2) highly isolated and (3) still interconnected populations. Seventeen landmarks on veins were used to analyse morphological variances in the wing shape. Our data show significant deviations between landmarks on the left and right wing side within individuals and strong morphological variance among individuals. The highest morphological variability could be found for individuals in the Alps, however, the level of asymmetry was very similar for all populations analysed. The higher morphological variability found in the Alps can be interpreted as a consequence of the higher level of the genetic diversity detectable for this region. Analysis on morphological variance of P. apollo individuals of the Mosel valley using time series ranging from 1895 until today showed no significant rise in asymmetry and no decline of morphological variability over time, although, anthropogenic habitat destruction has caused severe bottlenecks in this population.

On the knowledge of the geographic variation of the satyrid Oeneis jutta (Hübner, [1806]) (Lepidoptera, Satyridae) in the Northeast of European Russia

Analysis of the geographic variation of external characters of the satyrid Oeneis jutta (Lepidoptera, Satyridae) in the northeast of European Russia was carried out. Variation of the forewing length, diameter of eyespots, their total number and frequency of occurrence on the upper side of wings were studied. The regional populations of Oe. jutta were shown to lack significant differences in the characters studied. Besides the similarity of external characters, similar ecological traits also suggest that Oe. jutta populations from the northeast of European Russia belong to the nominative subspecies. The probable history of distribution of Oe. jutta across Europe also suggests that the nominative subspecies occurs in the territory studied.

Pattern of Post-Juvenile Moult in Common Snipe (Gallinago Gallinago) and Its Implications for Ageing of the Species

External ageing of Common Snipe (Gallinago gallinago) still engenders considerable problems. To improve precision of age determination on the basis of plumage characteristics a scheme of post-juvenile moult was investigated in approximately 1200 first-year Common Snipes caught during autumn migration in central Poland. Post-juvenile moult was commenced from body feathers followed by moult of rectrices, lesser/median wing coverts and tertials. Moult sequence showed high inter-individual variability and was started in rectrices (36.9%), wing coverts (25.3%), tertials (8.4%) or simultaneously in several of these tracts of feathers (29.4%). Moult of rectrices was finished before completion of moult of wing coverts and tertials. Moult of tertials finished as the last from all age-indicative tracts of feathers. Consequently, tertials were suggested as the most useful for ageing of first-year Common Snipes in an advanced stage of moult. There was no case of moult of the outermost tertial in first-year birds. The second tertial from distal side of wing was moulted as the last one within this tract of feathers and thereby should be of special interest during plumage examination.

Yaw Angle Effect on Flow Structure over the Nonslender Diamond Wing

Yaw Angle Effect on Flow Structure over the Nonslender Diamond Wing