高速铁路Y型声屏障动态特性数值研究

Numerical study on dynamic characteristics of Y-typed sound barrier in high-speed railway

以Y型声屏障为研究对象,建立高速列车-声屏障流体动力学和有限元仿真模型,模拟列车进出声屏障区域全过程,从列车速度、声屏障-列车距离、声屏障折板角度等因素研究Y型声屏障的动态响应特性。研究结果表明:当列车通过声屏障时,脉动风压呈明显的头波和尾波效应;沿高度方向脉动风压自下而上减小,在Y型折板处急剧下降,底部脉动风压约为顶部风压的1.77倍;Y型声屏障所受脉动风压随列车速度线性增大而加速增大,随声屏障-列车距离增加而减小,随折板角度增加而降低;Y型声屏障最大等效应力随折板角度增加而增大,其变化趋势与脉动风压的变化趋势相反;在实际工程中,应选择小角度(105°~135°)Y型声屏障,工程中应对声屏障底部结构进行加固并加强监测。

Computational fluid dynamics and finite element models of Y-typed sound barrier for high-speed railway were established to simulate the whole process of trains entering and leaving the sound barrier area.The dynamic response characteristics of Y-typed sound barrier were summarized from different factors,such as speeds of the train,distances between train and sound barrier and angles of sound barrier folded plate.The results show the aerodynamic impulse pressure has obvious head and tail wave effects when the train passes through the sound barrier.The aerodynamic impulse pressure along the height direction decreases from bottom to top,and decreases obviously at the Y-typed folded plate,and the aerodynamic impulse pressure at the bottom is about 1.77 times of that at the top.The aerodynamic impulse pressure on the Y-typed sound barrier non-linearly increases with the increase of train speed,decreases with the increase of distance between the sound barrier and the train,and decreases with the increase of flap angle.The maximum equivalent stress of Y-typed sound barrier increases with the increase of folded plate angle,and this trend is opposite to that of the aerodynamic impulse pressure.According to the regularities of aerodynamic impulse pressure and equivalent stress,Y-typed sound barrier with angle between 105° and 135° should be applied in practical engineering.The bottom of sound barrier should be reinforced and monitored in practice.