Effectiveness of hole plate-type sand barriers in reducing aeolian sediment flux: Evaluation of effect of hole size

摘要

Hole plate-type sand barriers can effectively control wind-sand disasters along the railways running through the windy Gobi desert region, and the hole diameter of hole plate is the key geometric parameter influencing their protective effect. To determine the effect of hole diameter on the wind-sand flow field of hole plate-type sand barriers, in this study, numerical simulations and wind tunnel tests were conducted on hole plate-type sand barriers with different hole diameters (1.03 cm, 2.06 cm, and 4.12 cm) but the same porosity (30%). The results showed that the protective effect of sand barriers presented regular changes with the change in hole diameter. Regarding the flow field, an increase in hole diameter increased the wind penetration rate of sand barrier, decreased the area of acceleration zone above the sand barrier, shortened the length of vortex zone on the leeward side, and lowered the degree of wind velocity reduction by sand barrier. Regarding the distribution of sand deposit, an increase in hole diameter decreased the sand deposits on the windward side of sand barrier, increased the sand deposits on the leeward side, and overall shifted the sand deposit on the leeward side towards the downwind direction. Moreover, hole diameter and sand interception of sand barrier showed a negative correlation. The sand interception of sand barrier with the smallest hole diameter (1.03 cm) exceeded the sand interceptions of the other two sand barriers by 5.41% and 13.43%, respectively. At different heights, the sand barrier with a relatively small hole diameter maintained a relatively high sand-retaining efficiency. The advantage was particularly significant within the height range of 0.5-1H. Moreover, the effective protection ranges of the three sand barriers were approximately the same. The effective protection interval approximately ranged from 1H on the windward side to 10H on the leeward side, and the effective protection height was found to be 1H.