摆动水翼的推力与流场结构数值研究  

Thrust Generation and Wake Structure of a Wiggling Hydrofoil

作　　者：何国毅[1,2] 张曙光[3] 张星[4] 

机构地区：[1]飞行器工程学院南昌航空大学,南昌330063 [2]航空科学与工程学院北京航空航天大学,北京100191 [3]交通科学与工程学院北京航空航天大学,北京100191 [4]中国科学院LNM力学研究所,北京100080

出　　处：《应用数学和力学》2010年第5期553-560,共8页Applied Mathematics and Mechanics

摘　　要：在一定的Reynolds数范围内,水生动物和微型仿生机械通常采用摆动的方式获得推力,这种摆动可以用行进波来表示,行进波的波长则描述了摆动生物的柔性.该文用浸入边界方法模拟了低Reynolds数情况下,水翼NACA-65-010在水中摆动时的流场.结果表明,水翼摆动产生推力的大小与行进波波长密切相关,随着波长的增大,推力系数减小,推进效率则在一定的波长值达到最大;推力的产生与两种流场结构有关:即反K偄rm偄n涡街和涡对,摆动水翼后缘尾迹中形成反K偄rm偄n涡街时产生的推力要大于尾迹中形成涡对产生时的推力.A wiggling motion is often used by marine animals and micro-machines to generate thrust.The wiggling motion can be modeled by a progressive wave where its wavelength describes the flexibility of wiggling animals.In the present study,an immersed boundary method was used to simulate the flows around the wiggling hydrofoil NACA-65-010 at low Reynolds numbers.It is found from the numerical simulations that the thrust generation is largely determined by the wavelength： The thrust coefficients decrease with increasing the wavelength while the propulsive efficiency reaches maximum at a certain wavelength.The latter is due to the viscous effects.The thrust generation is associated with two different flow patterns in the wake： the well-known reversed Krmn vortex streets and the vortex dipoles.Both of them are jet-type flows where the thrust coefficients associated with the reversed Krmn vortex streets are larger than the ones associated with vortex diploes.

关 键 词：推进效能 摆动 尾迹 浸入边界法 

分 类 号：O351[理学—流体力学]