An association between ear and tail morphologies of bats and their foraging style

2011 ◽  
Vol 89 (2) ◽  
pp. 90-99 ◽  
Author(s):  
James D. Gardiner ◽  
Jonathan R. Codd ◽  
Robert L. Nudds
Keyword(s):  
Body Size ◽  
Foraging Strategy ◽  
Aerodynamic Performance ◽  
Variance Analysis ◽  
Flight Performance ◽  
Wing Membrane ◽  
Trade Off ◽  
Scaling Relationships ◽  
Membrane Morphology ◽  
Foraging Flight

Most studies relating bat morphology to flight ecology have concentrated on the wing membrane. Here, canonical variance analysis showed that the ear and tail morphologies of bats also strongly relate to foraging strategy, which in turn is correlated with flight style. Variations in tail membrane morphology are likely to be a trade-off between increases in the mechanical cost of flight and improvements in foraging and flight performance. Flying with large ears is also potentially energetically expensive, particularly at high flight speeds. Large ears, therefore, are only likely to be affordable for slow foraging gleaning bat species. Bats with faster foraging flight styles tend to have smaller ears, possibly to cut the overall drag produced and reduce the power required for flight. Variations in the size of ears and tail membranes appear to be driven primarily by foraging strategy and not by body size, because the scaling relationships found are either weak or not significant. Ear size in bats may be a result of a trade-off between acoustic and aerodynamic performance.

scholarly journals Metoda Short Takeoff Landing (Studi Kasus Prestasi Terbang Takeoff-Landing Pesawat Udara Turbo Prop CN235)

WARTA ARDHIA ◽  
2017 ◽  
Vol 41 (2) ◽  
pp. 49
Author(s):  
Sayuti Syamsuar
Keyword(s):  
Critical Condition ◽  
Aerospace Industry ◽  
Aerodynamic Performance ◽  
Performance Data ◽  
Flight Performance ◽  
Aircraft Structure ◽  
Trade Off ◽  
Study Case ◽  
Full Throttle ◽  
Obstacle Height

The aircraft category of Short Take-Off Landing, in general, including lightweight aircrafts with take-off weight between 20.000 lb (9.072 kg) and 50.000 lb (22.680 kg) and capable in exceeding 50 ft (15 m) obstacle height with only 1.500 ft (450 m) of take-off and landing distance. Thera are, at least, three general requirements that have to be considered in order to develop this category of aircraft; high aerodynamic performance, powerful engine, qualified skill of pilot, and also the strength of aircraft structure that can sustain heavy load.As for the study case, the author used the flight performance data of CN235-100 (serial N-16) Short Field Landing with 230 flap that was tested in Indonesian Aerospace Industry in 1996 for its trade-off performance. There was also rejected take-off or accelerate stop distance test with 100 flap and full throttle where one of the engine, then suddenly, shut down in order to achieve critical condition and later the power of the another engine being reduced by the pilot so that the aircraft can stop at the end of the runway. Several pilot recommendations are given in the conclusion chapter. Keywords: short take-off landing, height, distance, performance, engine, pilot, flap. Pesawat dengan kategori Short Take-Off Landing pada umumnya adalah pesawat ringan yang mempunyai berat take-off antara 20.000 lb (9.072 kg) hingga 50.000 lb (22.680 kg) dengan kemampuan melewat irintangan setinggi 50 ft (15 m) untuk jarak take-off dan landing sejauh 1.500 ft (450 m). Pengembangan pesawat dengan kategori tersebut perlu memperhatikan tiga persyaratan umum yaitu kemampuan aerodinamika yang tinggi, tenaga mesin yang besar, dan teknik pilot yang baik yang disertai dengan kekuatan struktur yang mampu menahan beban berat. Pada studi kasus ini, penulis menggunakan data prestasi terbang Short Field Landing pesawat CN235-100 (serial N-16) dengan menggunakan flap 230 pada saat pengujian performance trade-off di PT Dirgantara Indonesia pada tahun 1996. Pengujian tersebut juga termasuk uji rejected take-off atau accelerate stop distance dengan menggunakan flap 100 pada tenaga penuh dimana kemudian salah satu mesin dimatikan untuk mencapai kondisi kritis dan pilot mengurangi daya propulsi mesin lainnya untuk dapat berhenti di ujung landasan. Beberapa rekomendasi pilot diberikan pada bagian kesimpulan. Kata kunci: short takeoff landing, tinggi, jarak, performance, engine, pilot, flap.

scholarly journals Numerical simulation of flapping airfoil with alula

2020 ◽  
Vol 12 ◽  
pp. 175682932097798
Author(s):  
Han Bao ◽  
Wenqing Yang ◽  
Dongfu Ma ◽  
Wenping Song ◽  
Bifeng Song
Keyword(s):  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Geometric Parameters ◽  
Flight Performance ◽  
Relative Angle ◽  
Vertical Distance ◽  
Unsteady Effect ◽  
Flapping Airfoil

Bionic micro aerial vehicles have become popular because of their high thrust efficiency and deceptive appearances. Leading edge or trailing edge devices (such as slots or flaps) are often used to improve the flight performance. Birds in nature also have leading-edge devices, known as the alula that can improve their flight performance at large angles of attack. In the present study, the aerodynamic performance of a flapping airfoil with alula is numerically simulated to illustrate the effects of different alula geometric parameters. Different alula relative angles of attack β (the angle between the chord line of the alula and that of the main airfoil) and vertical distances h between the alula and the main airfoil are simulated at pre-stall and post-stall conditions. Results show that at pre-stall condition, the lift increases with the relative angle of attack and the vertical distance, but the aerodynamic performance is degraded in the presence of alula compared with no alula, whereas at post-stall condition, the alula greatly enhances the lift. However, there seems to be an optimal relative angle of attack for the maximum lift enhancement at a fixed vertical distance considering the unsteady effect, which may indicate birds can adjust the alula twisting at different spanwise positions to achieve the best flight performance. Different alula geometric parameters may affect the aerodynamic force by modifying the pressure distribution along the airfoil. The results are instructive for design of flapping-wing bionic unmanned air vehicles.

Clutch Mass, Offspring Mass, and Clutch Size: Body Mass Scaling and Taxonomic and Environmental Variation

2018 ◽  
pp. 68-97
Author(s):  
Douglas S. Glazier
Keyword(s):  
Life History ◽  
Body Size ◽  
Clutch Size ◽  
Body Mass ◽  
Life History Evolution ◽  
Offspring Size ◽  
Egg Mass ◽  
Mass Scaling ◽  
Scaling Relationships ◽  
Clutch Mass

In this chapter, I show how clutch mass, offspring (egg) mass, and clutch size relate to body mass among species of branchiopod, maxillipod, and malacostracan crustaceans, as well as how these important life history traits vary among major taxa and environments independently of body size. Clutch mass relates strongly and nearly isometrically to body mass, probably because of physical volumetric constraints. By contrast, egg mass and clutch size relate more weakly and curvilinearly to body mass and vary in inverse proportion to one another, thus indicating a fundamental trade-off, which occurs within many crustacean taxa as well. In general, offspring (egg) size and number and their relationships to body mass appear to be more ecologically sensitive and evolutionarily malleable than clutch mass. The body mass scaling relationships of egg mass and clutch size show much more taxonomic and ecological variation (log-log scaling slopes varying from near 0 to almost 1 among major taxa) than do those for clutch mass, a pattern also observed in other animal taxa. The curvilinear body mass scaling relationships of egg mass and number also suggest a significant, size-related shift in how natural selection affects offspring versus maternal fitness. As body size increases, selection apparently predominantly favors increases in offspring size and fitness up to an asymptote, beyond which increases in offspring number and thus maternal fitness are preferentially favored. Crustaceans not only offer excellent opportunities for furthering our general understanding of life history evolution, but also their ecological and economic importance warrants further study of the various factors affecting their reproductive success.

Challenges and advances in the study of pterosaur flight

2015 ◽  
Vol 93 (12) ◽  
pp. 945-959 ◽  
Author(s):  
K.M. Middleton ◽  
L.T. English
Keyword(s):  
Body Size ◽  
Size Range ◽  
Flapping Flight ◽  
Flight Mechanics ◽  
Wing Membrane ◽  
Membrane Function ◽  
Aerodynamic Modeling ◽  
History Of ◽  
Bone Loading

Pterosaurs have fascinated scientists and nonscientists alike for over 200 years, as one of the three known clades of vertebrates to have evolved flapping flight. The smallest pterosaurs were comparable in size to the smallest extant birds and bats, but the largest pterosaurs were vastly larger than any extant flier. This immense size range, coupled with poor preservation and adaptations for flight unknown in extant vertebrates, have made interpretations of pterosaur flight problematic and often contentious. Here we review the anatomical, evolutionary, and phylogenetic history of pterosaurs, as well as the views, perspectives, and biases regarding their interpretation. In recent years, three areas of pterosaur biology have faced challenges and made advances: structure of the wing membrane, function of the pteroid, body size and mass estimates, as well as flight mechanics and aerodynamics. Comparative anatomical and fossil study, simulated bone loading, and aerodynamic modeling have all proved successful in furthering our understanding of pterosaur flight. We agree with previous authors that pterosaurs should be studied as pterosaurs, a diverse but phylogenetically, anatomically, and mechanically constrained clade that can offer new insights into the diversity of vertebrate flight.

scholarly journals Effects of Feather Lice on Flight Behavior of Male Barn Swallows (Hirundo Rustica)

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 213-216 ◽  
Author(s):  
A. Barbosa ◽  
S. Merino ◽  
Fde Lope ◽  
A. P. Møller
Keyword(s):  
Parasite Load ◽  
Hirundo Rustica ◽  
Flight Behavior ◽  
Flight Performance ◽  
Wingbeat Frequency ◽  
Feather Lice ◽  
Locomotory Performance ◽  
Flight Parameters ◽  
Barn Swallows ◽  
Foraging Flight

Abstract Parasites may affect host behavior in a number of ways, including their locomotory performance. We investigated whether the number of holes produced by the feather louse (Myrsidea rustica) affected flight behavior in adult male Barn Swallows (Hirundo rustica) by video-taping flight performance of individuals during escape and level flight. Percentage of time spent flapping during foraging flight was positively related to number of holes, but not to other flight parameters such as wingbeat frequency. These results suggest indirect effects of feather lice on host performance that must be considered together with effects of thermoregulation and feather breakage. This is the first report of an effect of parasite load on flight behavior.

scholarly journals Variable cant angle winglets for improvement of aircraft flight performance

Meccanica ◽  
2020 ◽  
Vol 55 (10) ◽  
pp. 1917-1947
Author(s):  
J. E. Guerrero ◽  
M. Sanguineti ◽  
K. Wittkowski
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Fuel Efficiency ◽  
Aerodynamic Performance ◽  
Flight Performance ◽  
Sweep Angle ◽  
Aircraft Flight ◽  
Induced Drag ◽  
Aircraft Performance

Abstract Traditional winglets are designed as fixed devices attached at the tips of the wings. The primary purpose of the winglets is to reduce the lift-induced drag, therefore improving aircraft performance and fuel efficiency. However, because winglets are fixed surfaces, they cannot be used to control lift-induced drag reductions or to obtain the largest lift-induced drag reductions at different flight conditions (take-off, climb, cruise, loitering, descent, approach, landing, and so on). In this work, we propose the use of variable cant angle winglets which could potentially allow aircraft to get the best all-around performance (in terms of lift-induced drag reduction), at different flight phases. By using computational fluid dynamics, we study the influence of the winglet cant angle and sweep angle on the performance of a benchmark wing at Mach numbers of 0.3 and 0.8395. The results obtained demonstrate that by adjusting the cant angle, the aerodynamic performance can be improved at different flight conditions.

scholarly journals Correlated evolution of neck length and leg length in birds

2019 ◽  
Vol 6 (5) ◽  
pp. 181588 ◽  
Author(s):  
Christine Böhmer ◽  
Olivia Plateau ◽  
Raphäel Cornette ◽  
Anick Abourachid
Keyword(s):  
Body Size ◽  
Vertebral Column ◽  
High Variability ◽  
Large Species ◽  
Leg Length ◽  
Neck Length ◽  
Correlated Evolution ◽  
Scaling Relationships ◽  
Extant Species ◽  
Total Leg

Despite a diversity of about 10 000 extant species, the sophisticated avian ‘body plan’ has not much changed once it was achieved around 160 Ma after the origin of powered flight. All birds are bipedal having wings, a rigid trunk, a short and ossified tail, a three-segmented leg and digitigrade feet. The avian neck, however, has always been regarded as a classic example of high variability ranging from short necks in songbirds to extremely long, serpentine necks in herons. Yet, the wide array of small to very large species makes it difficult to evaluate the actual neck length. Here, we investigate the evolution of the vertebral formulae in the neck of birds and the scaling relationships between skeletal dimensions and body size. Cervical count in birds is strongly related to phylogeny, with only some specialists having an exceptional number of vertebrae in the neck. In contrast with mammals, the length of the cervical vertebral column increases as body size increases and, thus, body size does not constrain neck length in birds. Indeed, neck length scales isometrically with total leg length suggesting a correlated evolution between both modules. The strong integration between the cervical and pelvic module in birds is in contrast with the decoupling of the fore- and hindlimb module and may be the result of the loss of a functionally versatile forelimb due to the evolution of powered flight.

scholarly journals Design of compliant mechanism-based variable camber morphing wing with nonlinear large deformation

2019 ◽  
Vol 16 (6) ◽  
pp. 172988141988674 ◽  
Author(s):  
Yaqing Zhang ◽  
Wenjie Ge ◽  
Ziang Zhang ◽  
Xiaojuan Mo ◽  
Yonghong Zhang
Keyword(s):  
Large Deformation ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Flight Performance ◽  
Morphing Wing ◽  
Structure Topology ◽  
Trailing Edges ◽  
Morphing Wings

The morphing wing with large deformation can benefit its flight performance a lot in different conditions. In this study, a variable camber morphing wing with compliant leading and trailing edges is designed by large-displacement compliant mechanisms. The compliant mechanisms are carried out by a hyperelastic structure topology optimization, based on a nonlinear meshless method. A laminated leading-edge skin is designed to fit the curvature changing phenomenon of the leading edge during deformation. A morphing wing demonstrator was manufactured to testify its deformation capability. Comparing to other variable camber morphing wings, the proposal can realize larger deflection of leading and trailing edges. The designed morphing wing shows great improvement in aerodynamic performance and enough strength to resist aerodynamic and structural loadings.

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