无反射造波数值波浪水槽

Numerical Wave Channel with Absorbing Wave-maker

本文应用VOF方法建立了二维数值波浪水槽模型。基于线性造波机理论在水槽左端设置了可吸收式造波机数值边界条件。即造波板的运动除了产生行进波外,同时还产生一个抵消反射波的局部波动。水槽右端除了通常的可滑移与无滑移直墙边界条件外,依据线性辐射条件建立了开边界条件。通过水槽右端为直墙时的全反射情形,比较了可吸收造波机与普通造波机的速度变化与波面变化。文中在H_0/d=0.1～0.3,d/L=0.124～0.219的范围内对数值波浪水槽的波浪特性进行了标定,给出了波高及波压力峰值沿水槽的分布,波面与波压力的历时曲线及不同时刻数值波浪水槽的流场。计算结果表明无反射数值波浪水槽工作特性良好,能够有效地消除造波板的二次反射,在波浪水槽内得到稳定的、重复性很好的波动过程。

The numerical wave channel has been developed based on the volume of fluid method (VOF). The absorbing wave maker boundary on the left side of the channel is presented by prescribing velocities reference to linear wave-maker theory. The principle of which is that the paddle of wave maker is designed to move in a way that generates the required incident wave and cancels out any reflected waves that reach it at the same time. On the right side of the channel, the open boundary is set to permit incident waves to be transmitted freely. The parametric studies have been carried out at a range of ratios of wave height in front of paddle to water depth Ho/d from 0. 1 to 0. 3, with water depth/wave length ratio d/L from 0. 124 to 0. 219. Wave height, wave pressure distributions along the channel and velocity fields are obtained for both absorbing wave maker and conventional wave maker. For a reflective case, it is shown that the absorbing wave-maker is very effective in canceling out the reflected wave that reaches the numerical paddle and highly repeatable waves can be achieved.