... in gliding is thus primarily influenced by the competing effects of reduced S and increased C V exhibited by swept wings. In the present study, swept wings during gliding appear to behave like the delta wings of aircraft. Previous work has shown that delta wings can produce lift at post-stall attack...

... linked with their wing motion. Lift Thrust Clap and peel Take-off Wingtip-reversal Flexed-wing Particle image velocimetry Takeoff, landing and slow flight are critical phases for all flying animals, whether foraging, evading predation or finding a mate. Slow flight (<3 m s −1...

... for this species-rich group to occupy freshwater systems. Using hydromechanical modeling, we show that occurrence in fresh water results in a two- to three-fold increase in negative buoyancy for sharks and rays. This carries the energetic cost of lift production and results in increased buoyancy-dependent...

... be a significant selective factor acting on body shape. On exposed shores, narrower arms probably reduce both lift and drag in breaking waves. On protected shores, fatter arms may provide more thermal inertia to resist overheating, or more body volume for gametes. Such plastic changes in body shape represent...

..., indicates that peak coefficients of lift and drag ( C L and C D ) and lift-to-drag ratio ( C L : C D ) increase throughout ontogeny and that these patterns correspond with changes in feather microstructure. To begin to place these results in a comparative context that includes variation in life-history...

... mean maximum lift was not significantly different from that required to support body mass (95±8%), mean wingbeat frequency was 23.7±0.6 Hz, and mean stroke amplitude was 105±5 deg in the forewing and 96±5 deg in the hindwing – all of which are close to free-flight values. Instead, the low cost...

... enabled us to observe the change in overall shape of the urchins and quantify the decrease in spine angle that occurred as flow speeds increased. The effect of this behaviour on drag and lift was measured with physical models made from urchin tests with spines in the `up' position (typical in stagnant...

... agreement between methods (mean differences 6.4% of wing length). We found that the wing in the upstroke posture is capable of producing substantial aerodynamic forces. At in vivo angles of attack (66 deg at mid-upstroke, 46 deg at mid-downstroke), the upstroke wings averaged for three birds produced a lift...

... considered are: (1) both the pectoral and pelvic fins spread out, (2) only the pectoral fins spread with the pelvic fins folded, and (3) both fins folded. The role of the pelvic fins was found to increase the lift force and lift-to-drag ratio, which is confirmed by the jet-like flow structure existing...

...William J. Stewart; Ian K. Bartol; Paul S. Krueger SUMMARY Although the pulsed jet is often considered the foundation of a squid's locomotive system, the lateral fins also probably play an important role in swimming, potentially providing thrust, lift and dynamic stability as needed. Fin morphology...

...D. Ishihara; Y. Yamashita; T. Horie; S. Yoshida; T. Niho SUMMARY We have studied the passive maintenance of high angle of attack and its lift generation during the crane fly's flapping translation using a dynamically scaled model. Since the wing and the surrounding fluid interact with each other...

..., and other factors such as animal mass and size have resulted in flippers that are unique among each species. Cetacean flippers may be viewed as being analogous to modern engineered hydrofoils, which have hydrodynamic properties such as lift coefficient, drag coefficient and associated efficiency. Field...

... Alectoris chukar as they engaged in WAIR (incline 65–85°; N =7 birds) and ascending flight(85°, N =2). To estimate lift and impulse, we coupled our DPIV data with three-dimensional wing kinematics from a companion study. The ontogeny of lift production was evaluated using three age classes: baby birds...

... kinematics lift pteropod swimming Flying and swimming animals across a range of sizes produce thrust by transferring momentum to the surrounding fluid medium using paired,oscillating appendages ( Vogel,1994 ). In general, propulsive forces are generated via two primary kinematic modes: flapping...

... address: Structure and Motion Laboratory,The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA,UK (e-mail: jusherwood@rvc.ac.uk ) 26 10 2004 © The Company of Biologists Limited 2005 2005 aerodynamics bird pigeon Columba livia flight power lift pressure...

...Z. Jane Wang SUMMARY Studies of insect flight have focused on aerodynamic lift, both in quasi-steady and unsteady regimes. This is partly influenced by the choice of hovering motions along a horizontal stroke plane, where aerodynamic drag makes no contribution to the vertical force. In contrast...

...Mao Sun; Jian Tang SUMMARY The lift and power requirements for hovering flight in Drosophila virilis were studied using the method of computational fluid dynamics. The Navier-Stokes equations were solved numerically. The solution provided the flow velocity and pressure fields, from which...

...James R. Usherwood; Charles P. Ellington SUMMARY Recent work on flapping hawkmoth models has demonstrated the importance of a spiral `leading-edge vortex' created by dynamic stall, and maintained by some aspect of spanwise flow, for creating the lift required during flight. This study uses...

... the relationship. (e-mail: jimusherwood@lycos.co.uk ) 21 3 2002 © The Company of Biologists Limited 2002 2002 aerodynamics flight propeller force coefficient lift drag wing High force coefficients are required to account for hovering flight in animals ranging from small...

... varies greatly along the longitudinal axis of the wing. This produces different local aerodynamic characteristics. Analyses of the C L / C D characteristics, where C L and C D are the lift and drag coefficients, respectively (at Reynolds numbers Re of 7880 and 10 000), using a force balance system, have...