双排高立式尼龙网阻沙障与草方格固沙障的优化配置及防沙效益

Optimized Configuration and Sand Control Benefits of Double-row High VerticalNylon Mesh Sand Barrier and Grass Lattice Sand Barrier

[目的]针对双排高立式尼龙网阻沙障与草方格固沙障联合应用,开展风洞试验研究,以优化联合沙障中尼龙网阻沙障孔隙度配置及探究各孔隙度下联合沙障的防沙效益。[方法]基于风洞模拟试验数据,开展不同孔隙度(40%,45%,55%)联合沙障,在不同风速下的风速流场、空气动力学粗糙度、摩阻风速、输沙率随高度和阻沙率方面的变化特征研究。[结果](1)相同风速下尼龙网阻沙障孔隙度40%时,联合沙障弱风区面积最大;(2)随着尼龙网阻沙障孔隙度的增大,空气动力学粗糙度和摩阻风速减小,相同风速和相同位置时,40%孔隙度下联合沙障空气动力学粗糙度和摩阻风速值最大;(3)风速增加地表输沙率也增加,联合沙障内部与背风侧输沙率随高度增加呈指数型递减,输沙主要集中在0~12 cm高度内;(4)风速大小与沙障阻沙率呈现负相关变化;阻沙率与孔隙度之间也呈负相关关系,孔隙度为40%的联合沙障具有较高阻沙率;双排高立式尼龙网阻沙措施与草方格固沙措施联合之间还存在阻沙率叠加。[结论]40%孔隙度的双排高立式尼龙网和草方格的阻固联合可以实现较优的配置与防沙效益。

[Objective]For the joint application of double-row high vertical nylon mesh sand barriers and grass checkerboard sand barriers,wind tunnel experimental studies were conducted to optimize the configuration of nylon mesh sand barriers porosity in the joint sand barriers and investigate the sand control benefits of the joint sand barriers under each porosity.[Methods]Based on the wind tunnel simulation experimental data,we carried out the characterization of the changes in the wind velocity flow field,aerodynamic roughness,friction wind velocity,sand transport rate with height,and sand blocking rate of the joint sand barriers with different porosities(40%,45%,and 55%)at different wind speeds.[Results](1)The area of wind shadow zone of the joint sand barrier was the largest at 40%porosity of nylon mesh sand barrier under the same wind speed.(2)As the porosity of the nylon mesh sand barrier increases,the aerodynamic roughness and friction wind speed decreased,and the values of aerodynamic roughness and friction wind speed of the joint sand barrier at 40%porosity were the largest at the same wind speed and the same location.(3)The sand transport rate on the surface increased with the increase of wind speed.Inside and on the leeward side of the joint sand barriers,the sand transport rate decreased exponentially with the increase of height,and the sand transport was mainly concentrated at the height of 0~12 cm.(4)Wind speed and sand barrier rate showed a negative correlation;sand barrier rate and porosity also showed a negative correlation,the porosity of 40%of the joint sand barriers had a better sand barrier rate;double rows of high vertical nylon mesh sand barriers and grass checkerboard sand fixation measures combined with the sand barrier rate superposition also existed.[Conclusion]Therefore,the combination of double-row vertical nylon mesh with 40%porosity and grass checkerboards can realize better configuration and sand control benefits.