铁路侧向导沙沙障流场演化规律研究

Study on the characteristics of the flow field evolution of the lateral guide rail

铁路沿线的侧向导沙工程主要应用于风沙来流的侧向输导,使线路免受风沙危害。应用CFD数值模拟方法研究铁路沿线羽毛状侧向导沙沙障周围的流场演化规律特征,通过研究不同主风向与沙障夹角以及在风速改变时沙障周围的流场分区特征,揭示侧向输导沙障周围的流场机理。研究结果表明:羽毛排周围流场显著区别于其他挡风沙构筑物的流场规律,回流区随着主风向与羽毛排夹角的增大而增大,当主风向与羽毛排夹角小于30°时,流场分区显示降速区即积沙区在迎风侧一侧而偏离线路;羽毛排周围的回流区会影响羽毛排前方的速度大小,使速度廓线产生波动,主风向与羽毛排的夹角小于30°时波动较小,利于风沙侧向输导,使过境风沙流向远离线路方向运动。

Lateral sand guiding engineering along the railway line is mainly used in lateral migration of sand to make the railway from the sand.In this paper,CFD numerical simulation was used to study the characteristics of the flow field around the plume side of the plume along the railway,based on the study of the angle between the main wind direction and the sand barrier and the flow field characteristics around the sand barrier and to further reveal flow field around the mechanism of sand barrier of lateral migration.The results show that:the flow field around row of feathers is significantly different from that of other structures;recirculation zone increases with the increase of the angle between the main wind direction and row of feathers,when the angle between the main wind direction and row of feathers is less than 30 degrees;flow field zone displays that speed drop zone or sand sedimentary area is located at the side of the wind and departures from the railway line;the recirculation zone around the row of feathers affects the velocity distribution of the plume front,which makes the velocity profile fluctuates,when the angle between the main wind direction and row of feathers is less than 30 degrees;and when the fluctuation is smaller,it is conducive to the lateral migration on sand flow,making the flow of wind blown away from the direction of railway lines.