Numerical simulation of the influence of wind erosionon reverse flat plate of external dump in arid zone

MA Li; MA Ning; BI Yinli; PENG Suping; WANG Xiaomin; HU Shengxuan; NI Weijie; ZHANG Qifeng; LI Mengbo

Abstract：The water resources of open-pit mines in arid areas are scarce,and the wind speed in the external dumping site is high,which leads to a decrease in plant survival rate and is not conducive to ecological restoration.To effective-ly address the impact of strong winds on plant survival rate,this article takes the Hongshaquan open-pit mine as an ex-ample and uses Fluent software to simulate the size and variation pattern of windless areas at different retaining wall heights in the external dumping site under wind speeds of 6 m/s to 10 m/s.Based on the size of the windless area,the optimal height of the retaining wall in the external dumping site is determined to be 2 m.Considering the im-pact of the retaining wall height on the dumping operation,a 1m retaining wall combined with a 1m wind and dust sup-pression network structure is adopted.At the same time,setting up a reverse flat plate structure in the external dump-ing site can effectively increase the windless area compared to the traditional horizontal arrangement of flat plates,re-duce the evaporation of water in the soil,weaken the harm of wind and sand to plants,and improve the survival rate of plants in the arid area of the external dumping site compared to the traditional horizontal layout of flat plates.Based on large eddy simulation,the range of windless areas under different wind speeds was studied under the conditions of re-verse flat plate angles of 5°,10°,15°,and 20°.The optimal angle of flat plate inclination in the external dumping site and the windless area of the third stage structure of reverse flat plate under different wind speed conditions were deter-mined.The results show that as the angle increases,the windless area first increases and then decreases at the same speed,and the influence of angle on the windless area is not significant;At the same angle,as the speed increases,the windless area gradually decreases.According to the simulation results,it was found that the maximum range of the windless area is 2.8 m when the angle is 10°,Determine 10° as the most suitable angle,the reverse design of retaining walls and dumping sites can to some extent increase the range of windless areas and reduce wind speed,which is bene-ficial for plant growth.The reverse three-level flat plate structure has a smaller windless area in the middle flat plate,and the largest windless area in the bottom flat plate.Higher plants can be planted in the bottom flat plate,while low-er growing plants can be planted in the middle flat plate.