琵琶柴的防风固沙作用数值模拟  

Numerical simulation on the windbreak and sand-fixing effect of Reaumuria soongorica

作　　者：刘洋[1] 尹忠东[1] 闫晴 张彩荣 LIU Yang;YIN Zhongdong;YAN Qing;ZHANG Cairong(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《干旱区研究》2024年第11期1887-1897,共11页Arid Zone Research

基　　金：新疆水土保持监督管理项目(213031003)。

摘　　要：植物固沙是北方干旱、半干旱区防治风沙灾害的重要措施之一,其中琵琶柴(Reaumuria soongorica)为荒漠区分布最广泛的半灌木,具有重要的应用价值。本文利用计算平台Fluent对琵琶柴植株附近的流场进行数值模拟,分析风速特征和积沙特征。结果表明:(1)在10 m·s^(-1)初始风速下,植株前后皆会形成涡流,其高度和强度与距植株远近有关,整体低于0.25 m。(2)数值模拟结果表明,气流水平方向速度的变化多呈“N”和“W”型曲线,而垂直方向的气流速度变化则为“V”型曲线。(3)在较低风速下,非生长季琵琶柴的阻风效能要优于生长季,株后防护距离4 m;当风速大于6 m·s^(-1)时,双排生长季琵琶柴株后风速降低幅度可大于94.45%。(4)琵琶柴具有良好的阻沙效果,在初始风速为6 m·s^(-1)时,大部分沙粒堆积在植株前后底部;当风速增至10 m·s^(-1)时,生长季琵琶柴阻沙良好,沙粒主要沉积在株后1.5~3 H,沙粒堆积高度小于0.1 m;当初始风速为15 m·s^(-1)时,生长季琵琶柴株后积沙主要分布在株后2~3.5 H,而非生长季琵琶柴沙粒堆积范围则在株后1~10 H。无论何种生长季琵琶柴均能有效降低风场内气流速度,并对气流所携带的沙粒具有良好的沉降作用,在植物治沙工程中起重要作用。Vegetation-based sand fixation is a key measure to control wind and sand disasters in the arid and semiarid regions of northern China.Reaumuria soongorica,a semi-shrub widely distributed in desert areas,holds a significant application value in this context.This study used Fluent software to perform numerical simulations of the airflow fields around R.soongorica during various growth seasons,analyzing wind speed characteristics and sand deposition patterns.The research yielded the following conclusions:(1)At an initial wind speed of 10 m·s^(-1),vortices form in front of and behind the plant,with their height and intensity varying with the distance from the plant,generally below 0.25 m.(2)The numerical simulation results indicate that changes in horizontal airflow speed often exhibit N-and W-shaped curves,while vertical airflow speed changes follow a V-shaped curve.(3)At lower wind speeds,the wind-blocking effect of R.Soongorica in the non-growing season is better than that in the growing season,with a protection distance of 4 m behind the plant;when the wind speed is greater than 6 m·s^(-1),the wind speed reduction behind double rows of R.Soongorica growing season can be greater than 94.45%.(4)R.soongorica has excellent sand-blocking effects.At an initial wind speed of 6 m·s^(-1),most sand particles accumulate at the plant base,in front and behind it.When the wind speed increases to 10 m·s^(-1),R.soongorica during the vigorous season effectively blocks sand,with sand particles primarily depositing between 1.5-3 H behind the plant,with a height lower than 0.1 m.At an initial wind speed of 15 m·s^(-1),sand deposition behind the vigorous season R.soongorica is mainly distributed between height 2-3.5 H.In contrast,for the withering season,sand accumulation ranges from height 1-10 H behind the plant.Regardless of the growth season,R.soongorica effectively reduces airflow speed within the wind field and promotes the settling of sand particles carried by the airflow,playing a crucial role in vegetation-based sand co

关 键 词：防风阻沙 琵琶柴 风速变化 积沙分布 Fluent数值模拟 

分 类 号：S727.23[农业科学—林木遗传育种]