列车与隧道环隙空间流场特性的研究

列车通过隧道时,列车表面与隧道表面之间的环隙流场特性,是隧道空气动力学的一个重要内容,也是研究和解决隧道活塞风的主要依据之一.本文从管道湍流理论出发,认为环隙流动由两种流动组合而成:一是由环隙压力梯度产生的Poiseuille型粗糙区湍流;一是由列车表面曳力产生的 Couette型湍流.根据粗糙区管道湍流理论,利用镜像原理和相对运动原理,通过流动变换,建立Couette型湍流的基本关系;应用时均湍流性质和坐标变换方法,得出环隙组合流动规律;提出环隙流动的速度分布关系式和特征速度位置的关系式;确定与壁面剪切力密切相关的壁摩擦速度.本文的研究内容可为解决隧道活塞风问题提供参考.

Characteristics of Flow Field in Annulus Space between Train and Tunnel

The characteristics of flow fields in annuluses between moving and static walls formed in train running through a tunnel is the important content of tunnel aerodynamics and also one of the main bases to study and solve the problem of the piston wind in tunnels. According to the pipe turbulence theory,the annulus flow is viewed as the combination of two kinds of flow,namely the Poiseuille turbulence in rough areas caused by the annulus pressure gradient and the Couette turbulence caused by drag forces on train surfaces. On the basis of the pipe turbulence theory in rough areas and taking advantage of the mirror and relative movement principles,the essential relationship of the Couette turbulence is established through flow transformation;by the property of time-averaged turbulence and the method of coordinate transformation,the law of annulus combination flow is deduced:the velocity distribution relationship and characteristic velocity location relationship of annulus flow are put forward,the wall friction velocity closely related to wall shear stresses is determined. The research provides the main baseis for solving the problem of tunnel piston wind.