Aerodynamic performance of owl-like airfoil undergoing bio-inspired flapping kinematics  

作　　者：Xinyu LANG Bifeng SONG Wenqing YANG Wenping SONG 

机构地区：[1]School of Aeronautics,Northwestern Poly technical University,Xi'an 710072,China [2]Research&Development Institute of Northwestern Polytechnical University in Shenzhen,Shenzhen 518057,China [3]Yangtze River Delta Research Institute of Northwestern Polytechnical University,Taicang 215400,China

出　　处：《Chinese Journal of Aeronautics》2021年第5期239-252,共14页中国航空学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.11872314 and U1613227);the China Scholarship Council,Key R&D Program in Shaanxi Province of China(No.2020GY-154);Natural Science Basic Research Plan in Shaanxi Province of China(No.2019JQ-394)。

摘　　要：Natural flyers have extraordinary flight skills and their prominent aerodynamic performance has attracted a lot of attention.However,the aerodynamic mechanism of birds’flapping wing kinematics still lacks in-depth understanding.In this paper,the aerodynamic performance of owl-like airfoil undergoing bio-inspired flapping kinematics extracted from a free-flying owl wing has been numerically investigated.The overset mesh technique is used to deal with the large range movements of flapping airfoils.The bio-inspired kinematics consist of plunging and pitching movement.A pure sinusoidal motion and a defined motion composed of plunging of sinusoidal motion and pitching of the bio-inspired kinematics are selected for comparison.The other two NACA airfoils are also selected to figure out the advantages of the owl-like airfoil.It is found that the cambered owl-like airfoil can enhance lift during the downstroke.The bio-inspired kinematics have an obvious advantage in lift generation with a presence of higher peak lift and positive lift over a wider proportion of the flapping cycle.Meanwhile,the bio-inspired motion is more economical for a lower power consumption compared with the sinusoidal motion.The sinusoidal flapping motion is better for thrust generation for a higher peak thrust value in both upstroke and downstroke,while the bio-inspired kinematics mainly generate thrust during the downstroke but produce more drag during the upstroke.The defined motion has similar lift performance with the bio-inspired kinematics,while it consumes more energy and generates less thrust.The unsteady flow field around airfoils is also analyzed to explain the corresponding phenomenon.The research in this paper is helpful to understand the flight mechanism of birds and to design a micro air vehicle with higher performance.

关 键 词：Aerodynamic performance Bio-inspired kinematics Flapping airfoils Low Reynolds number Micro aerial vehicles 

分 类 号：V211.41[航空宇航科学与技术—航空宇航推进理论与工程]