Shape reconstructions and morphing kinematics of an eagle during perching manoeuvres  

作　　者：Di Tang Dawei Liu Hai Zhu Xipeng Huang Zhongyong Fan Mingxia Lei 唐迪;刘大伟;朱海;黄喜鹏;范忠勇;雷鸣霞(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310014,China;High Speed Aerodynamic Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China;Zhejiang Museum of Natural History,Hangzhou 310014,China)

机构地区：[1]College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310014,China [2]High Speed Aerodynamic Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China [3]Zhejiang Museum of Natural History,Hangzhou 310014,China

出　　处：《Chinese Physics B》2020年第2期327-336,共10页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.51705459);the China Postdoctoral Science Foundation.

摘　　要：The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry.A three-jointed arm model is proposed to associate with the 3D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions.The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3 D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3 D wing geometry.A three-jointed arm model is proposed to associate with the 3 D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3 D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3 D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions.

关 键 词：large BIRD of PREY shape reconstruction MORPHING KINEMATIC PERCHING 

分 类 号：Q811[生物学—生物工程]