基于风洞模拟的槽状沙障防风效应试验OA

In order to prevent serious hollowing out at the bottom of a vertical-mesh sand barrier,a concave sur-face is formed in the barrier.This causes the barrier to develop a skewed edge,changes its area,and reduces its protective benefits.Here,we propose a new"trough-shaped"sand barrier.This shape enhances both its resistance to wind erosion and its ground adhesion by covering sand to increase its own weight.Based on wind-tunnel tests at three wind speeds—6 m·s-1,9 m·s-1,and 12 m·s-1—we obtained wind-speed data for trough-shaped sand barri-ers with different heights and angles(i.e.,the same height at the front and back,a lower front and higher back,and angle type).By calculating and analyzing the flow-field structure,we investigated in detail the wind-speed profile and acceleration rate,as well as the wind-protection effect.The results show that a trough-shaped sand bar-rier can reduce the wind speed effectively and that the overall wind-protection effect is reflected in five character-istic areas that affect the near-surface air movement significantly.At a fixed angle,an increase in the height of the sand barrier increases the rate of acceleration of the airflow.However,the angle of the sand barrier must not be too large in order to avoid weakening the windproofing effect.After we set up the sand barriers,we found that the surface roughness decreased with an increase in the incoming wind speed and that the drag velocity increased lin-early with the wind speed.This study thus establishes an optimized design theory with supporting technological frameworks for sand-control engineering,facilitating evidence-based decision-making in practice.