Effects of aspect ratio on flapping wing aerodynamics in animal flight

作     者：Jun-Jiang Fu Csaba Hefler Hui-He Qiu Wei Shyy 

作者机构：Department of Mechanical and Aerospace EngineeringThe Hong Kong University of Science & Technology 

出 版 物：《Acta Mechanica Sinica》 (力学学报（英文版）)

年 卷 期：2014年第30卷第6期

页      面：776-786页

核心收录：

学科分类：08[工学] 09[农学] 0901[农学-作物学] 0836[工学-生物工程] 090102[农学-作物遗传育种] 

基　　金：supported by the Innovation Technology Commission(ITC)of the Government of the Hong Kong Special Administrative Region(HKSAR)with Project(ITS/115/13FP) Hong Kong Ph.D.Fellowship Scheme from the Research Grants Council(RGC) 

主　　题：Aspect ratio Aerodynamics Leading edge vortex Flapping wing 

摘      要：Morphology as well as kinematics is a critical determinant of performance in flapping *** understand the effects of the structural traits on aerodynamics of bioflyers,three rectangular wings with aspect ratios（AR）of1,2,and 4 performing hovering-like sinusoidal kinematics at wingtip based Reynolds number of 5 300 are experimentally *** structures on sectional cuts along the wing span are *** K-H instability is found on the leading edge vortex of wings with higher aspect *** bursting only appears on the outer spanwise locations of high-aspect-ratio *** vortex bursting on high-aspect-ratio wings is perhaps one of the reasons why bio-flyers normally have low-aspect-ratio *** analysis exhibits larger dimensionless circulation of the leading edge vortex（LEV）over higher aspect ratio wings except when vortex bursting *** average dimensionless circulation of AR1 and AR2 along the span almost equals the dimensionless circulation at the 50%*** flow structure and the circulation analysis show that the sinusoidal kinematics suppresses breakdown of the LEV compared with simplified flapping kinematics used in similar *** Reynolds number effect results on AR4 show that in the current Re range,the overall flow structure is not sensitive to Reynolds number.