scholarly journals Morphology, flight performance, and water crossing tendencies of Afro-Palearctic raptors during migration

2015 ◽  
Vol 61 (6) ◽  
pp. 951-958 ◽  
Author(s):  
Nicolantonio Agostini ◽  
Michele Panuccio ◽  
Cristian Pasquaretta
Keyword(s):  
Energy Consumption ◽  
Aspect Ratio ◽  
Meta Analysis ◽  
Energetic Cost ◽  
Flight Performance ◽  
Energetic Costs ◽  
Wing Area ◽  
Gliding Flight ◽  
Water Surfaces ◽  
Maximum Water

Abstract Raptors primarily use soaring-gliding flight which exploits thermals and ridge lifts over land to reduce energetic costs. However during migration, these birds often have to cross water surfaces where thermal currents are weak; during these times, birds mainly use flapping (powered) flight which increases energy consumption and mortality risk. As a result, some species have evolved strategies to reduce the amount of time spent over water by taking extensive detours over land. In this paper, we conducted a meta-analysis of water-crossing tendencies in Afro-Palearctic migrating raptors in relation to their morphology, their flight performance, and their phylogenetic relationships. In particular, we considered the aspect ratio (calculated as the wing span squared divided by wing area), the energetic cost of powered flight, and the maximum water crossing length regularly performed by adult birds. Our results suggest that energy consumption during powered flight predominately affects the ability of raptors to fly over water surfaces.

Wing Morphology and Flight Behaviour of the Golden-Tipped Bat, Phoniscus Papuensis (Dobson) (Chiroptera: Vespertilionidae)

1995 ◽  
Vol 43 (6) ◽  
pp. 657 ◽  
Author(s):  
MP Rhodes
Keyword(s):  
Aspect Ratio ◽  
Habitat Preference ◽  
Flight Performance ◽  
Wing Morphology ◽  
Wing Loading ◽  
Wing Area ◽  
Flight Behaviour

The wing morphology and flight performance of Phoniscus papuensis was examined to determine whether the wing morphology reflected published observations of flight behaviour and habitat preference. Wingspan and wing area were above the vespertilionid average for its mass. The wing loading and aspect ratio were below average. The wing loading is the lowest of any Australian vespertilionid. P. papuensis was able to successfully negotiate arrays of obstacles 22 cm apart 60% of the time. This ability, and the extremely broad, lightly loaded wings, afford the species unique flight characteristics which have been observed in the field and allow flight in complex, 'closed' habitats.

scholarly journals Power of the wingbeat: modelling the effects of flapping wings in vertebrate flight

2015 ◽  
Vol 471 (2177) ◽  
pp. 20140952 ◽  
Author(s):  
M. Klein Heerenbrink ◽  
L. C. Johansson ◽  
A. Hedenström
Keyword(s):  
Energetic Cost ◽  
Flight Performance ◽  
Large Parameter ◽  
Body Area ◽  
Wingbeat Frequency ◽  
Wing Area ◽  
Wing Motion ◽  
Animal Flight ◽  
Flight Model ◽  
Blade Element

Animal flight performance has been studied using models developed for man-made aircraft. For an aeroplane with fixed wings, the energetic cost as a function of flight speed can be expressed in terms of weight, wing span, wing area and body area, where more details are included in proportionality coefficients. Flying animals flap their wings to produce thrust. Adopting the fixed wing flight model implicitly incorporates the effects of wing flapping in the coefficients. However, in practice, these effects have been ignored. In this paper, the effects of reciprocating wing motion on the coefficients of the fixed wing aerodynamic power model for forward flight are explicitly formulated in terms of thrust requirement, wingbeat frequency and stroke-plane angle, for optimized wingbeat amplitudes. The expressions are obtained by simulating flights over a large parameter range using an optimal vortex wake method combined with a low-level blade element method. The results imply that previously assumed acceptable values for the induced power factor might be strongly underestimated. The results also show the dependence of profile power on wing kinematics. The expressions introduced in this paper can be used to significantly improve animal flight models.

scholarly journals Gliding flight in a jackdaw: a wind tunnel study

2001 ◽  
Vol 204 (6) ◽  
pp. 1153-1166 ◽  
Author(s):  
M. Rosen ◽  
A. Hedenstrom
Keyword(s):  
Wind Tunnel ◽  
Bird Species ◽  
Wind Tunnels ◽  
Flight Performance ◽  
Forward Speed ◽  
Wing Area ◽  
Reference Length ◽  
Gliding Flight ◽  
Speed Range ◽  
Maximum Coefficient

We examined the gliding flight performance of a jackdaw Corvus monedula in a wind tunnel. The jackdaw was able to glide steadily at speeds between 6 and 11 m s(−1). The bird changed its wingspan and wing area over this speed range, and we measured the so-called glide super-polar, which is the envelope of fixed-wing glide polars over a range of forward speeds and sinking speeds. The glide super-polar was an inverted U-shape with a minimum sinking speed (V(ms)) at 7.4 m s(−1) and a speed for best glide (V(bg)) at 8.3 m s(−)). At the minimum sinking speed, the associated vertical sinking speed was 0.62 m s(−1). The relationship between the ratio of lift to drag (L:D) and airspeed showed an inverted U-shape with a maximum of 12.6 at 8.5 m s(−1). Wingspan decreased linearly with speed over the whole speed range investigated. The tail was spread extensively at low and moderate speeds; at speeds between 6 and 9 m s(−1), the tail area decreased linearly with speed, and at speeds above 9 m s(−1) the tail was fully furled. Reynolds number calculated with the mean chord as the reference length ranged from 38 000 to 76 000 over the speed range 6–11 m s(−1). Comparisons of the jackdaw flight performance were made with existing theory of gliding flight. We also re-analysed data on span ratios with respect to speed in two other bird species previously studied in wind tunnels. These data indicate that an equation for calculating the span ratio, which minimises the sum of induced and profile drag, does not predict the actual span ratios observed in these birds. We derive an alternative equation on the basis of the observed span ratios for calculating wingspan and wing area with respect to forward speed in gliding birds from information about body mass, maximum wingspan, maximum wing area and maximum coefficient of lift. These alternative equations can be used in combination with any model of gliding flight where wing area and wingspan are considered to calculate sinking rate with respect to forward speed.

A multi-country meta-analysis on the role of behavioural change in reducing energy consumption and CO2 emissions in residential buildings

Nature Energy ◽  
2021 ◽  
Author(s):  
Tarun M. Khanna ◽  
Giovanni Baiocchi ◽  
Max Callaghan ◽  
Felix Creutzig ◽  
Horia Guias ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Co2 Emissions ◽  
Residential Buildings ◽  
Meta Analysis ◽  
Behavioural Change ◽  
Reducing Energy

Aerodynamics of Gliding Flight of a Black Vulture Coragyps Atratus

1970 ◽  
Vol 53 (2) ◽  
pp. 363-374 ◽  
Author(s):  
G. CHRISTIAN PARROTT
Keyword(s):  
Wind Tunnel ◽  
Wing Area ◽  
Drag Coefficients ◽  
Wing Span ◽  
Drag Forces ◽  
Gliding Flight ◽  
Black Vulture ◽  
Air Speed

1. A black vulture (mass = 1.79 kg) gliding freely in a wind tunnel adjusted its wing span and wing area as its air speed and glide angle changed from 9.9 to 16.8 m/s and from 4.8° to 7.9°, respectively. 2. The minimum sinking speed was 1.09 m/s at an air speed of 11.3 m/s. 3. The maximum ratio of lift to drag forces was 11.6 at an air speed of 13.9 m/s. 4. Parasite drag coefficients for the vulture are similar to those for conventional airfoils and do not support the contention that black vultures have unusually low values of parasite drag.

Energetics of walking and running: insights from simulated reduced-gravity experiments

1992 ◽  
Vol 73 (6) ◽  
pp. 2709-2712 ◽  
Author(s):  
C. T. Farley ◽  
T. A. McMahon
Keyword(s):  
Body Weight ◽  
Energy Consumption ◽  
Energetic Cost ◽  
Reduced Gravity ◽  
Low Levels

On Earth, a person uses about one-half as much energy to walk a mile as to run a mile. On another planet with lower gravity, would walking still be more economical than running? When people carry weights while they walk or run, energetic cost increases in proportion to the added load. It would seem to follow that if gravity were reduced, energetic cost would decrease in proportion to body weight in both gaits. However, we find that under simulated reduced gravity, the rate of energy consumption decreases in proportion to body weight during running but not during walking. When gravity is reduced by 75%, the rate of energy consumption is reduced by 72% during running but only by 33% during walking. Because reducing gravity decreases the energetic cost much more for running than for walking, walking is not the cheapest way to travel a mile at low levels of gravity. These results suggest that the link between the mechanics of locomotion and energetic cost is fundamentally different for walking and for running.

Soaring and Gliding Flight of the Black Vulture

1958 ◽  
Vol 35 (2) ◽  
pp. 280-285
Author(s):  
B. G. NEWMAN
Keyword(s):  
Flow Separation ◽  
Angle Of Attack ◽  
High Angle ◽  
High Angle Of Attack ◽  
Wing Area ◽  
Wing Span ◽  
Gliding Flight ◽  
Black Vulture ◽  
Wing Geometry

1. The soaring and gliding performance of the black vulture has been analysed and the following conclusions are drawn. 2. The wing span of the bird is altered in flight so that it may perform two tasks efficiently. First, that it may soar in rising currents of air for which a low sinking speed and thus a large wing span are required. Secondly, that it may penetrate into wind without undue loss of height for which a reduced wing area is desirable. Adjustment of the wing geometry towards the optimum soaring configuration is achieved by bending forward and opening the primary tip feathers. 3. Since the airflow readily separates from the flat primary feathers at high angle of attack, these feathers, which are emarginated, are parted to form slots. The alula also presumably assists in delaying the flow separation over the primaries. 4. It is unlikely that the opening of the primaries reduces the vortex drag.

scholarly journals Increasing the efficiency of a Peltier device by assessing the thermal performance of liquid-cooled microchannel heat sinks

2020 ◽  
Vol 7 ◽  
Author(s):  
System Administrator ◽  
Lauren Sharpe ◽  
Navil Burhanuddin ◽  
Tiana Majcan ◽  
Jonathan Rebolledo
Keyword(s):  
Energy Consumption ◽  
Meta Analysis ◽  
Heat Sinks ◽  
Peltier Effect ◽  
Small Scale ◽  
Specific Flow ◽  
Operating Current ◽  
Promising Solution ◽  
Peltier Device ◽  
Vital Resource

Water is, arguably, Earth's most valuable and vital resource. Devices that extract water from the atmosphere have been intensely researched as a means of harvesting potable water in environments where it is otherwise scarce. One such device is a Thermoelectric Cooler (TEC); a device that utilises the Peltier effect to cool a system. TECs are a promising solution for atmospheric water generation (AWG) over their competitors due to their simplicity and refrigeration capabilities. Despite these advantages, TECs are still considered mostly inefficient as they demand relatively high costs and energy consumption. This meta-analysis focuses on optimising the efficiency of small-scale Peltier devices. It explores the means of optimising the liquid cooled heat sink by using a specific flow field microchannel configuration such that less pumping power is required to push the coolant and more energy can be saved. A combination of optimal operating current of the Peltier device and of a novel flow liquid-cooled microchannel heatsink configuration with bifurcated fins using Galinstan as a coolant promises a significant increase in water production per unit of energy consumption for the AWG system.

Preload does not influence nonmechanical O2 consumption in isolated rabbit heart

1994 ◽  
Vol 266 (3) ◽  
pp. H1047-H1054 ◽  
Author(s):  
A. Higashiyama ◽  
M. W. Watkins ◽  
Z. Chen ◽  
M. M. LeWinter
Keyword(s):  
Energy Consumption ◽  
Diastolic Pressure ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Energetic Cost ◽  
O2 Consumption ◽  
Time Integral ◽  
Force Time ◽  
Whole Heart ◽  
Force Time Integral

Myocardial energy consumption for nonmechanical activity (excitation-contraction coupling) has been shown to be length dependent in isolated muscle studies but no more than minimally affected by preload in the whole heart. However, unloaded O2 consumption (VO2, which is used to estimate nonmechanical VO2 in whole heart) may not be accurate for quantifying nonmechanical energy consumption, because it contains VO2 for residual cross-bridge cycling. To more accurately determine the influence of left ventricular (LV) diastolic volume on nonmechanical VO2 in whole heart, we employed a new method for quantifying nonmechanical VO2, using the drug 2,3-butanedione monoxime (BDM). We measured VO2 and force-time integral during infusion of BDM (< or = 5 mM) at high (VH) and low LV volumes (VL) in 16 excised isovolumically contracting red blood cell-perfused rabbit ventricles. LV end-diastolic pressure was 9.7 +/- 4.6 and 3.8 +/- 2.8 (SD) mmHg at VH and VL, respectively. Nonmechanical VO2, estimated as the VO2-axis intercept of the linear VO2-force-time integral relation obtained during BDM infusion, did not differ significantly between VH and VL (0.0137 +/- 0.0083 and 0.0132 +/- 0.0090 ml O2.beat-1 x 100 gLV-1, P = 0.702). A multiple linear regression analysis for the pooled data confirmed this finding (P = 0.361). We conclude that, in the rabbit heart, LV diastolic volume does not importantly affect nonmechanical energy consumption over a physiological range of LV end-diastolic pressure. This indicates that length-dependent activation does not have an energetic cost in whole rabbit heart and suggests that its predominant mechanism is increased Ca2+ affinity for the contractile proteins.

scholarly journals The energetic costs of living in the surf and impacts on zonation of shells occupied by hermit crabs

2020 ◽  
Vol 223 (16) ◽  
pp. jeb222703 ◽  
Author(s):  
Guillermina Alcaraz ◽  
Brenda Toledo ◽  
Luis M. Burciaga
Keyword(s):  
Water Flow ◽  
Wave Action ◽  
Hermit Crabs ◽  
Energetic Cost ◽  
Shell Shape ◽  
Energetic Costs ◽  
Shell Size ◽  
Conical Shells ◽  
Drag Forces ◽  
Submerged Body

ABSTRACTCrashing waves create a hydrodynamic gradient in which the most challenging effects occur at the wave breaking zone and decrease towards the upper protected tide pools. Hydrodynamic forces depend on the shape of the submerged body; streamlined shapes decrease drag forces compared with bluff or globose bodies. Unlike other animals, hermit crabs can choose their shell shape to cope with the effects of water flow. Hermit crabs occupy larger and heavier shells (conical shape) in wave-exposed sites than those used in protected areas (globose shape). First, we investigated whether a behavioral choice could explain the shells used in sites with different wave action. Then, we experimentally tested whether the shells most frequently used in sites with different wave action reduce the energetic cost of coping with water flow. Metabolic rate was measured using a respirometric system fitted with propellers in opposite walls to generate bidirectional water flow. The choice of shell size when a large array of sizes are available was consistent with the shell size used in different intertidal sites; hermit crabs chose heavier conical shells in water flow conditions than in still water, and the use of heavy conical shells reduced the energetic cost of coping with water motion. In contrast to conical shells, small globose shells imposed lower energy costs of withstanding water flow than large globose shells. The size and type of shells used in different zones of the rocky shore were consistent with an adaptive response to reduce the energetic costs of withstanding wave action.

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