中文摘要：

集沙仪是研究土壤风蚀必不可少的仪器之一,为提高集沙效率和自动采集数据的准确性,需要不断地对集沙仪进行优化设计。该文以FLUENT软件和微型风洞为试验平台,对分流对冲式集沙仪风沙分离器的排气管直径、排气管长度、排沙口直径、排沙口收缩高度进行了优化设计。数值模拟和风洞试验的结果显示：改进型风沙分离器排气口和排沙口的降速性能与原风沙分离器相比有了明显的提高,强风条件（13.8 m/s）下,排气管直径、长度均为25 mm,排沙口直径、收缩高度分别为75、15 mm时,气流对集沙仪自动采集传感器的冲击力最小,排气口最高风速比原风沙分离器降低了7.47%,排沙口最高风速比原风沙分离器降低了35.59%,改进后的集沙仪集沙效率比原集沙仪提高了1.56%。

英文摘要：

Soil erosion is a serious environmental problem in arid and semi-arid regions,which has aroused wide concern among the public.Soil erosion is the process of denudation,sorting and transportation of farmland soil under the action of wind.Soil erosion can cause soil texture coarse,structure deterioration,decline of soil fertility and decrease of sustainable productivity,seriously restricting the sustainable development of agriculture.Sand sampler is one of necessary devices to research soil erosion,which is a key equipment in the observation of sand flow structure and laws of wind and sand movement.In addition,it is necessary to optimize the design of sand sampler so that we can obtain a large and accurate erosion data to improve the sand collection efficiency.However,the core component of the shunt hedging sand sampler is a sand separator.In addition,according to the combination of shunt hedging and multistage expansion,the wind speed reduction effect is more obvious,and the sand collection efficiency can be higher.In this paper,the FLUENT software and the micro wind tunnel are used as experimental platform to optimize the exhaust pipe diameter,exhaust pipe length,sand outlet diameter,and sand outlet contraction height of the separator of the shunt hedging sand sampler.Furthermore,the finite element model of the sand separator for the shunt hedging sand sampler was established.Meanwhile,according to the RNG turbulence model,the numerical simulation analysis is carried out for sand sampler.Besides,the DEM model is used to calculate the trajectory of sand particles entering the sand separator so that we can easily obtain the sand collection efficiency.Besides,through the low speed performance test and gas-solid separation efficiency test,the simulation results of the original sand separator and the optimized sand separator in FLUENT are verified based on indoor micro wind tunnel.Moreover,the numerical simulation and wind tunnel test results show that the exhaust pipe and sand outlet deceleration performance of the o