梧桐树叶模型在风中的振动和受力分析

Vibration and force analysis of platanus acerifolia leaf model in wind

制作梧桐树叶模型,通过改变树叶某一尺寸来寻找影响树叶振动的因素,发现叶柄尺寸对叶片振动有明显的影响.树叶模型会随着风速的增长出现从静止到左右大幅度低频摆动、叶片停止摆动重新稳定以及再一次从静止到上下小幅度高频振动三个过程.使用风洞天平测量梧桐树叶模型在风中的受力,发现叶柄长度和叶片大小是影响阻力系数的两个关键因素,其中叶柄长度在雷诺数相对较低时对阻力系数影响较大,而叶片大小在雷诺数相对较高时影响较大.

The acerifolia leaf model was established to find the factors affecting the leaves＇ vibration. It was found that the size of petiole had significant influence on leaves＇ vibration. With the increase of wind speed, the leaf model changed from static state to sway in large amplitude and low frequency, then stopped sway and rested again. We measured the platanus aeerifolia leaf model＇s stress in wind by using the wind-tunnel balance. We found that the petiole length and the leaf size were two key factors that affected the resistance coefficient of leaves. The petiole length had a great influence on resistance coefficient when the Reynolds number was relatively lower. The effect of leaf size on the resistance coefficient was greater when the Reynolds number was relatively higher.