新建格库铁路组装式多周期HDPE板防风沙机理研究

Research on the mechanism of wind-sand control of assembled multi-cycle HDPE board at Geku railway

通过ANSYS数值模拟研究了不同孔隙率组装式多周期HDPE板固沙土工格在不同风速下流场变化、防护距离以及积沙形态变化过程。结果表明:当气流通过HDPE板时,在其周围形成六个速度分区,分别为迎风侧正压低速区、抬升增速区、集流加速区、第一、第二负压减速区和速度恢复区;当风速较小时,大孔隙率HDPE板的防护距离大于小孔隙率的防护距离,当风速较大时,不同孔隙率HDPE板防护距离变化不大;HDPE板内积沙形态随时间是一个动态变化的过程,当风速较小时,比较容易形成规则的凹曲面;大孔隙率HDPE板防沙形式以积沙为主,小孔隙率的HDPE板以阻沙为主;HDPE板内积沙量受风速和孔隙率影响明显,同一风速下孔隙率越小,板内平均积沙厚度越小,积沙量越少,同一孔隙率下风速越小HDPE板内以及板前积沙厚度越大,积沙量越多。

In this research,the variation of flow field and sand accumulation process and the protective distance of assembled multi-cycle board with different porosity under different wind speed were carried out by ANSYS numerical simulation.The results show that when the airflow passes through the HDPE board,six velocity zones are formed around it,they are positive pressure low air speed zone at windward side,air uplift acceleration zone,air flow accelerated zone,the first and second negative pressure air deceleration zone,air speed recovery zone;when the wind speed is small,the protective distance of HDPE board with large porosity is longer than that of the small porosity;when the wind speed is large,protective distance change of the HDPE board with different porosity is not obvious;the shape of sand accumulation in HDPE board is a dynamic process with time;when the wind speed is small,it is easier to form a regular concave surface;sand control of the HDPE board with large porosity is dominated by sand accumulation,while the HDPE board with small porosity is dominated by sand resistance;the amount of sand accumulation in HDPE board is obviously influenced by the wind speed and porosity,the smaller the porosity under the same wind speed,the smaller the average thickness of sand accumulation,the smaller the amount of sand;the smaller the wind speed under the same porosity,the greater the thickness of sand around the HDPE board,the more the amount of sand.