活塞和圆盘涡环的运动学特征分析

上海交通大学学报（自然版） ›› 2016, Vol. 50 ›› Issue (02): 294-299.

活塞和圆盘涡环的运动学特征分析

秦苏洋，向阳，刘洪

(上海交通大学航空航天学院, 吴镇远空气动力学研究中心，上海 200240)

收稿日期:2014-10-29 出版日期:2016-02-29 发布日期:2016-02-29
基金资助:
国家重点基础研究发展规划（973）项目(2014CB744802），国家自然科学基金重点项目(NSFC9144

Comparative Study of Kinematics Characteristics of Vortex Rings Generated by Piston and Disc

QIN Suyang,XIANG Yang,LIU Hong

(J. C. Wu Center for Aerodynamics, School of Aeronautics and Astronautics, Shanghai Jiaotong University, Shanghai 200240, China)

Received:2014-10-29 Online:2016-02-29 Published:2016-02-29

摘要/Abstract

摘要： 摘要：采用数值模拟方法，使用流函数和拉格朗日相关结构对由2种生长机制所得涡环的典型物理特征进行分析.结果表明：由2种生长机制所得涡环均属于薄核涡环，其涡核的涡量分布满足高斯分布，并且具有统一的物理模型；但由于2种涡环生长过程中的环境差异而导致其运动学特征存在差异，主要表现在涡环的传输速度和无量纲涡核半径有所不同.

关键词: 涡环, 运动学特征, 流函数, 拉格朗日相关结构

Abstract: Abstract： Numerical methods were used to simulate the formation of vortex rings while the methods of stream function and Lagrangian coherent structures were applied to analyze the physical characteristics of vortex rings. It is found that the vortex rings generated by two mechanisms belong to thin core vortex. The distribution of vorticity in core is Gauss distribution which has a unified model. Due to the difference between formation environments, there are several differences between kinematics characteristics, mainly in transportation velocity and nondimensional core radius. Thus, the pure vortex rings generated by piston can reveal the mechanism of the flow over a body which is like disc and airfoil.

Key words: Key words： vortex ring, kinematics characteristics, stream function, Lagrangian coherent structures

中图分类号:

O 357.1

秦苏洋，向阳，刘洪. 活塞和圆盘涡环的运动学特征分析[J]. 上海交通大学学报（自然版）, 2016, 50(02): 294-299.

QIN Suyang,XIANG Yang,LIU Hong. Comparative Study of Kinematics Characteristics of Vortex Rings Generated by Piston and Disc [J]. Journal of Shanghai Jiaotong University, 2016, 50(02): 294-299.

参考文献

［1］FISH F E, LANDER G V. Passive and active flow control by swimming fishes and mammals［J］. Annual Review of Fluid Mechanics, 2006, 38: 193224. ［2］DABIRI J O, COLIN S P, COSTELL J H, et al. Flow patterns generated by oblate medusa jellyfish: Field measurements and laboratory analyses［J］. Journal of Experimental Biology, 2005, 208: 12571265. ［3］DABIRI J O, GHARIB M, COLIN S P, et al. Vortex motion in the ocean: In situ visualization of jellyfish swimming and feeding flows［J］. Physics of Fluids, 2005, 17(9): 0911081. ［4］DABIRI J O. Optimal vortex formation as a unifying principle in biological propulsion［J］. Annual Review of Fluid Mechanics, 2009, 41:1733. ［5］SAFFMAN P G. Vortex dynamics［M］. Cambridge: Cambridge University Press, 1992. ［6］NORBURY J. A family of steady vortex rings［J］. Journal Fluid Mechanics, 1973, 57(3): 417431. ［7］GHARIB M, RAMBOD E, SHARIFF K. A universal time scale for vortex ring formation［J］. Journal Fluid Mechanics, 1998, 360: 121140. ［8］ROSENFELD M, RAMBOD E, GHARIB M. Circulation and formation number of laminar vortex rings［J］. Journal Fluid Mechanics, 1998, 376: 297318. ［9］TAYLOR G I. Formation of a vortex ring by giving an impulse to a circular disc and then dissolving it away［J］. Journal of Applied Physics, 1953, 24(1): 104105. ［10］SALLET D W. Impulsive motion of a circular disk which causes a vortex ring［J］. Physics of Fluids, 1975, 18(1): 109111. ［11］YANG A L, JIA L B, YIN X Z. Formation process of the vortex ring generated by an impulsively started circular disc［J］. Journal Fluid Mechanics, 2012, 713: 6185. ［12］DIDDEN N. On the formation of vortex rings: Rollingup and production of circulation［J］. J App Math Phys, 1979, 30(1): 10116. ［13］KRUEGER P S. An overpressure correction to the slug model for vortex ring circulation［J］. Journal Fluid Mechanics, 2005, 545: 427443. ［14］HALLER G, POJE A C. Finitetime transport in aperiodic flows［J］. Physica D: Nonlinear Phenomena, 2000, 119(34): 352380. ［15］HALLER G. Lagrangian structures and the rate of strain in a partition of twodimensional turbulence［J］. Physics of Fluids, 2001, 13(11): 33683385. ［16］SHADDEN S C, LEKIEN F, MARSDEN J E. Definition and properties of Lagrangian coherent structures from finitetime Lyapunov exponents in twodimensional aperiodic flows［J］. Physica D: Nonlinear Phenomena, 2005, 212(3/4): 271304. ［17］SHADDEN S C, DABIRI J O, MARSDEN J E. Lagrangian analysis of fluid transport in empirical vortex ring flows［J］. Physics of Fluids, 2006, 18(4):047105111. ［18］SHUSSER M, GHARIB M. Energy and velocity of a forming vortex ring［J］. Physics of Fluids, 2000, 12(3): 618621. ［19］SULLIVAN I S, NIEMELA J J, HERSHBERGER R E. Dynamics of thin vortex rings［J］. Journal Fluid Mechanics, 2008, 609:319347.