Usherwood James R, Hedrick Tyson L, Biewener Andrew A
Concord Field Station, Harvard University, 100 Old Causeway Road, Bedford, MA 01730, USA.
J Exp Biol. 2003 Nov;206(Pt 22):4051-6. doi: 10.1242/jeb.00624.
Direct pressure measurements using electronic differential pressure transducers along bird wings provide insight into the aerodynamics of these dynamically varying aerofoils. Acceleration-compensated pressures were measured at five sites distributed proximally to distally from the tertials to the primaries along the wings of Canada geese. During take-off flight, ventral-to-dorsal pressure is maintained at the proximal wing section throughout the wingstroke cycle, whereas pressure sense is reversed at the primaries during upstroke. The distal sites experience double pressure peaks during the downstroke. These observations suggest that tertials provide weight-support throughout the wingbeat, that the wingtip provides thrust during upstroke and that the kinetic energy of the rapidly flapping wings may be dissipated via retarding aerodynamic forces (resulting in aerodynamic work) at the end of downstroke.
使用电子差压传感器沿着鸟类翅膀进行直接压力测量，有助于深入了解这些动态变化的翼型的空气动力学特性。沿着加拿大鹅的翅膀，从三级飞羽到初级飞羽，在从近端到远端分布的五个位置测量了加速度补偿压力。在起飞飞行过程中，在整个翼行程周期内，近端机翼部分的腹侧到背侧压力保持不变，而在向上挥翅时，初级飞羽处的压力感应则相反。在向下挥翅过程中，远端位置会经历双重压力峰值。这些观察结果表明，三级飞羽在整个翅膀拍动过程中提供重量支撑，翼尖在向上挥翅时提供推力，并且快速拍动翅膀的动能可能在向下挥翅结束时通过阻碍空气动力（导致空气动力功）而耗散。
