高立式沙障不同水平组合模式对近地表流场的扰动及数值模拟

High vertical sand barriers are one of the important measures to prevent hazard of sand-wind in arid sandy areas, especially in some districts which are affected severely by terrible sandstorms. Under these circumstances, it needs a multi-channel sandy combination configuration to prevent and control desertification. The influence of sand barrier is the hot topics that attracts attention in the field of sand control project.. Firstly, we build mathematical models of partial differential equations according to the movement of air flow phenomenon around the high vertical sand barriers with fixed spacing between two rows, we use finite element method for simulation, we further analyze the changes of air flow with different spacing.Secondly, considering gas-solid flow, we improve the mathematical model to find the dynamic changes of the cross-section shape of surface sand, the amount of sand and wind sand flow in the late period of sand barrier. Numerical simulation is used to discuss the effects of different spacing treatments on prevention. In the end, we optimize the structure of the configurations about the high vertical sand barriers. Comparing three types of configurations: two rows、 three rows andfour rows, we analyze the result of sandification control. We also give comprehensive analysis of the optimal scheme about sand barriers allocation. . Through numerical simulation, field observation and wind tunnel experiment, we show the essence of transformation of sand flow in well-distributed structure sandy barrier. We hope our fruit can provide scientific method and theoretical basis for sand control engineering and the interaction mechanism of sand flow field and sand dynamics mechanism.

沙障是极端干旱沙区重要的防沙措施之一,在风沙危害较严重的地区,需要多道沙障组合配置进行防沙,在长时间风沙流动行为下,沙障组合配置对阻沙效果的影响是当今防沙工程领域关注的热点问题. . 首先本项目建立固定间距下两组高立式沙障周边纯气流场变化的偏微分方程模型，利用有限元方法数值求解,并分析不同间距流场的动态变化情况.其次考虑气固两相流动，对模型进行改进,讨论两组均匀结构高立式沙障防沙中期及后期的积沙形态、积沙量和气流场的动态变化,利用数值模拟，分析沙障间距对防沙效果的影响.最后分析不同组合配置结构，对比分析两组、三组、四组配置方式防风固沙的效果.综合分析给出最优的沙障组合配置方案以及各种水平配置方式的适用范围.. 本项目数值模拟与野外观测、室内风洞实验相结合,揭示不同水平组合高立式沙障周边风沙流场变化的本质.为防沙工程与风沙流场的互馈机制和风沙动力学机理提供了科学方法及理论基础.

沙障是极端干旱沙区重要的防沙措施之一,在风沙危害较严重的地区,需要多道沙障组合配置进行防沙,在长时间风沙流动行为下,沙障组合配置对阻沙效果的影响是当今防沙工程领域关注的热点问题.首先本项目建立固定间距下两组高立式沙障周边纯气流场变化的偏微分方程模型，利用有限元方法数值求解,并分析不同间距流场的动态变化情况.其次考虑气固两相流动，对模型进行改进,讨论两组均匀结构高立式沙障中期及后期气流场的动态变化,利用数值模拟，分析沙障间距对防风效果的影响.最后分析不同组合配置结构，对比分析两组、三组、四组配置方式防风固沙的效果.综合分析给出最优的沙障组合配置方案以及各种水平配置方式的适用范围.本项目数值模拟与室内风洞实验相结合,揭示不同水平组合高立式沙障周边风沙流场变化的本质.为防沙工程与风沙流场的互馈机制和风沙动力学机理提供了科学方法及理论基础.