不同运动条件下足球气动力及流场分析

AERODYNAMICS AND FLUID FIELD ANALYSIS OF SOCCER BALL UNDER VARIOUS MOTION STATES

为了获得足球空气动力学特性,建立了计算模型,并利用Fluent软件分别计算了无自旋及有自旋条件下的足球绕流场.仿真结果与已有工作相比较为合理.在无自旋条件下,通过分析足球表面极限流线发现接缝使得足球表面分离线与圆球明显不同,接缝深刻地影响三维分离情况,而且还会对足球所受升力大小产生影响;在自旋条件下,足球受到的Magnus力随旋转速度变大而变大;同时还发现,足球受到阻力也会随其旋转速度变大而变大.最后,本文还以一粒定位球罚球为例考察了足球旋转对其运动轨迹的影响.

To study the aerodynamic performance of the soccer ball, computational models with/without spinning axe set up and verified with previous studies. It is shown that the separation lines on the surface of the soccer ball are very different from those on a smooth ball surface due to presence of the seams. It is shown that the seams greatly affect the three-dimensional separation and the lift force acted on the soccer ball in non-spinning case. In the spinning case, not only the Magnus force but also the drag acted on the soccer ball increase with the increase of the rotation speed. Furthermore, the effect of spinning on the flight trajectory of the soccer ball is discussed with the penalty kick as an example.