新型风声屏障参数对车−桥系统气动特性的影响

Parametric study on aerodynamic characteristics of train−bridge system for a new type of wind-noise barrier

为满足穿越城区的轨道交通高架线路的防风和降噪需求,提出一种新型风声屏障结构,通过风洞试验研究屏障主要气动影响参数即叶片倾角变化对车−桥气动力的影响规律,并通过风压分布研究屏障倾角变化对车−桥气动力的影响机理。研究结果表明:列车气动力随新型风声屏障倾角变化而变化,倾角变化对列车表面局部风压影响明显;使用组合倾角屏障时,可同时对车顶和车底转角处风压进行调节,但该区域脉动风压提高;屏障风荷载是引起桥梁气动力变化的主因,与直立式声屏障自身风载相比,倾角为组合状态的风声屏障自身风载最大降低22%;安装新型风声屏障可降低桥梁迎风侧表面脉动风压系数,下倾姿态叶片有利于减小桥梁升力,使用新型风声屏障有利于桥梁和屏障自身结构安全。

In order to meet the wind resistance and noise reduction requirements of the elevated lines for the train crossing the urban area,a new type of wind-sound barrier was proposed.The main aerodynamic influencing parameter of the barrier,i.e.the blade inclination angle,on the aerodynamic force of train and bridges was studied by wind tunnel test,and the change of aerodynamic force was explored from the wind pressure distribution.The results show that aerodynamic force of the train changes with the change of inclination angle of the new wind noise barrier,and the change of the inclination angle has obvious influence on the local wind pressure on the surface of the train.When the combined inclination angle barrier is used,the wind pressure at the corners of the roof and the bottom of the train can be adjusted at the same time,but the pulsating wind pressure in this area will increase.Wind load of barrier is the main cause of bridge aerodynamic changes,and compared with the vertical sound barrier,the combined inclination wind sound barrier reduces its own wind load by up to 22%.The installation of new type wind-noise barrier can reduce the fluctuating wind pressure coefficient on the windward side of the bridge,and blades with downward inclination are beneficial to reduce the bridge lift.The use of a new type of wind sound barrier is beneficial to the structural safety of the bridge and the barrier itself.