气固分离式沙障防沙性能研究  

Study of sand-control performance of air-solid separating sand barriers

作　　者：赵呈冉 ZHAO Cheng-ran(China Railway First Survey and Design Institute Group Co.Ltd.,Lanzhou 730000,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,甘肃兰州730000

出　　处：《泥沙研究》2023年第4期61-66,共6页Journal of Sediment Research

基　　金：中国中铁股份有限公司科技开发计划课题(2015-KJ035-G004-03)。

摘　　要：针对风沙流中气、固相介质运动特征的显著差异性,提出一种新型高效的气固分离式沙障,并借助风洞试验研究了不同风速下的沙障周围的流场特征和阻沙效率,同时对其防沙稳定性和防沙机理进行了深入探讨。研究结果表明:风沙流途经沙障时,气流因阻碍效应在其迎风侧形成减速区,因文丘里效应在其正上方形成高速区,因逆压梯度和涡旋流在其背风侧形成紊流区;沙障顶部以下范围,水平风速近似呈“U”形分布,而沙障顶部以上范围,水平风速近似呈“Ω”形分布;随着来流风速的增大,沙障周围的风速呈递增趋势,但其阻沙率呈轻微的递减趋势,表明气固分离式沙障对环境风速的敏感性较弱,在多风速环境下较传统沙障的稳定性更高。该沙障利用多次绕流达到大幅提高阻沙的效率,这种新思路可为类似的沙障提供借鉴,对工程防沙具有重要的应用价值。According to the significant differences in the motion characteristics of air and solid phase media in wind-sand flow,a new type air-solid separating sand barrier with high-efficiency is proposed,the flow field characteristics around the barrier and its sand-blocking efficiencies under different wind speeds are studied by using wind tunnel tests,and its sand-control stability and mechanism are also discussed thoroughly.The results show that when the wind-sand flow passes through the barrier,the airflow forms a deceleration zone on the windward side due to the obstruction effect,a high-speed zone directly above the barrier due to the venturi effect,and a turbulent zone on the leeward side due to the inverse pressure gradient and vortex flow.The profiles of horizontal wind velocity is approximately distributed in a"U"shape below the top of the barrier and approximately in an"Q"shape above the top of the barrier.As the incoming wind velocity increases,the air flow velocity around the barrier tends to increase gradually,however the sand-resistance rate of the barrier decreases slightly,which indicating that the air-solid barrier is less sensitive to surrounding wind velocity and its stability is higher than that of conventional sand barriers in multi-wind velocity environments.This new idea of using multiple bypasses to significantly increase the sand-blocking efficiency can provide reference and guidance for the similar sand barriers and has important application value for sand control in railway projects.

关 键 词：气固分离式沙障 防沙性能 流场结构 阻沙率 风洞试验 

分 类 号：U216.413[交通运输工程—道路与铁道工程]