...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Journal of Experimental Biology >Flight kinematics of the barn swallow (Hirundo rustica) over a wide rangeof speeds in a wind tunnel
【24h】

Flight kinematics of the barn swallow (Hirundo rustica) over a wide rangeof speeds in a wind tunnel

机译：燕子（Hirundo Rustica）在风洞中的各种速度下的飞行运动学

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Two barn swallows (Hirundo rustica) flying in the Lund wind tunnel were filmed using synchronised high-speed cameras to obtain posterior, ventral and lateral views of the birds in horizontal flapping flight. We investigated wingbeat kinematics, body tilt angle, tail spread and angle of attack at speeds of 4-14 m s(-1). Wingbeat frequency showed a clear U-shaped relationship with air speed with minima at 8.9 m s(-1) (bird 1) and 8.7 m s(-1) (bird 2). A method previously used by other authors of estimating the body drag coefficient (C-D,C-par) by obtaining agreement between the calculated minimum power (V-min) and the observed minimum wingbeat frequency does not appear to be valid in this species, possibly due to upstroke pauses that occur at intermediate and high speeds, causing the apparent wingbeat frequency to be lower. These upstroke pauses represent flap-gliding, which is possibly a way of adjusting the force generated to the requirements at medium and high speeds, similar to the flap-bound mode of flight in other species. Body tilt angle, tail spread and angle of attack all increase with decreasing speed, thereby providing an additional lift surface and suggesting an important aerodynamic function for the tail at low speeds in forward flight. Results from this study indicate the high plasticity in the wingbeat kinematics and use of the tail that birds have available to them in order to adjust the lift and power output required for flight.
机译：使用同步高速相机拍摄了在隆德风洞飞行的两只燕子（Hirundo Rustica），以获取在水平拍打飞行中鸟类的后视图，腹视图和侧面视图。我们研究了4-14 m s（-1）速度下的机翼运动学，机体倾斜角，尾巴扩展和迎角。翼拍频率显示出与空气速度呈明显的U形关系，最小值为8.9 m s（-1）（鸟1）和8.7 m s（-1）（鸟2）。其他作者先前使用的通过获得计算的最小功率（V-min）与观察到的最小机翼拍频之间的一致性来估算车身阻力系数（CD，C-par）的方法在该物种中似乎无效，可能是由于在中速和高速下出现上冲程停顿，导致表观拍打频率降低。这些上冲停顿表示襟翼滑行，这可能是一种调节中速和高速产生的力以达到要求的方式，类似于其他物种的襟翼滑行飞行方式。机体倾斜角，尾翼扩展和迎角都随着速度的降低而增加，从而提供了额外的升力面，并暗示了低速前进时尾巴具有重要的空气动力学功能。这项研究的结果表明，机翼运动学中具有很高的可塑性，并且可以利用鸟所拥有的尾巴来调节飞行所需的升力和动力输出。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号