铁路风屏障的气动绕流及风吹雪特性研究

Aerodynamic Ambient Flow around Railway Wind Screens and Features of Drifting Snow

为进一步了解高寒地区铁路沿线针对西部强风设置的铁路风屏障,本文以空气动力学原理及气固两相流理论为基础,采用CFD数值模拟技术对铁路风屏障的气动绕流现象及风吹雪特性进行研究。分别考察不同透孔率条件下不同类型风屏障对线上车辆气动绕流特性的影响,并以透孔率30%轻型风屏障为代表研究不同风屏障高度、设置位置,不同来流风速及雪粒子粒径下的风屏障风吹雪特性。研究结果表明:透孔率30%轻型风屏障的设置对列车气动力改善效果最优;高度4.5m、距线路4m、透孔率30%轻型屏障引起的后方风吹雪灾害相对最小,来流风速及雪粒子粒径分别对线路附近区域积雪厚度有不同程度影响。

To further understand the wind screens established along the railway line in the frigid plateau region against the strong west wind ,based on aerodynamic principle and gas‐solid two‐phase flow theory ,this paper presented an analysis on the aerodynamic ambient flow of railway wind screens and drifting snow features caused by wind screens , using CFD numerical simulation technology . The impacts of various types of wind screens under different through‐hole rates on the aerodynamic ambient flow of on‐line vehicles were investiga‐ted , and the light wind screen with 30% through‐hole rate was chosen as a typical case to study drifting snow features around wind screens with diversified incoming flow speeds , wind screen heights , wind screen loca‐tions and snow grain sizes . The results showed that the light wind screen with 30% through‐hole rate can pro‐vide optimal improvement to aerodynamic force of the train .Wind screens with a height of 4.5 m ,a distance of 4 m from the railway line and with 30% through‐hole rate may reduce the drifting snow disaster to the rela‐tively minimum extent . Snow grain sizes and incoming flow speeds separately had different degrees of effects on snow cover thickness near the line .