Aerodynamic Performance of a Flapping Foil with Asymmetric Heaving Motion near a Wall

作     者：Xingjian Lin Shuhao Guo Jie Wu Jingwen Nan 

作者机构：Department of Aerodynamics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Nanjing 210016 China 

出 版 物：《Journal of Bionic Engineering》 (仿生工程学报（英文版）)

年 卷 期：2018年第15卷第4期

页      面：636-646页

核心收录：

学科分类：0710[理学-生物学] 0831[工学-生物医学工程（可授工学、理学、医学学位）] 081302[工学-建筑设计及其理论] 08[工学] 080103[工学-流体力学] 080104[工学-工程力学] 0813[工学-建筑学] 0836[工学-生物工程] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by Fundamental Research Funds for the Central Universities 江苏高校优势学科建设工程 

主　　题：asymmetric heaving motion wall effect thrust enhancement positive mean lift 

摘      要：The effect of asymmetric heaving motion on the aerodynamic performance of a two-dimensional flapping foil near a wall is studied numerically. The foil executes the heaving and pitching motion simultaneously. When the heaving motion is symmetric, the mean thrust coefficient monotonically increases with the decrease in mean distance between foil and wall. Meanwhile, the mean lift coefficient first increases and then decreases sharply. In addition, the negative mean lift coefficient appears when the foil is very close to the wall. After the introduction of asymmetric heaving motion, the influence of wall effect on the force behavior becomes complicated. The mean thrust coefficient is enhanced when the duration of upstroke is reduced. Moreover, more and more enhancement can be achieved when the foil approaches the wall gradually. On the other hand, the positive mean lift coefficient can be observed when the duration of downstroke is shortened. By checking the flow patterns around the foil, it is shown that the interaction between the vortex shed from the foil and the wall can greatly modify the pressure distribution along the foil surface. The results obtained here might be utilized to optimize the kinematics of the Micro Aerial Vehicles （MAVs） flying near a solid wall.