基于Micro-PIV和LBM的土壤孔隙网络中流体速度分布表征
发布时间：2019-03-20 13:16
【摘要】：土壤孔隙结构复杂多变,揭示其内部流场特性对于描述和预测土壤中水分传输、溶质迁移等现象至关重要.基于规则性的土壤孔隙网络模型,采用Micro-PIV(Micro-scale Particle Image Velocimetry,显微粒子成像测速系统)技术分析不同雷诺数下孔隙结构中流体运动的特征,通过LBM方法(Lattice Boltzmann Method,晶格玻尔兹曼方法)对孔隙结构中流场分布进行数值模拟研究.结果表明:微观尺度下孔隙网络模型中不同孔隙区域流速分布差异明显,中线区域流场呈规律性分布,孔喉处为高速区,流速达到0.001 4 m/s,水平方向相邻两圆柱靠近边界处存在低速区,速度不高于0.000 2 m/s,在垂直于流向方向上速度场具有良好的对称性;靠近上下边界的大孔隙区域流体优先通过,流体的速度可达到0.003 0 m/s.LBM方法模拟的孔隙网络模型中流场分布结果与试验获得的流场分布吻合,其平均均方根误差为0.009 4 m/s,表明土壤孔隙网络模型能有效模拟土壤孔隙,捕捉微观尺度上的流体运动特征,为应用孔隙网络模型研究土壤孔隙中溶质运移和反应等问题提供了微观尺度的度量工具.
[Abstract]:The pore structure of soil is complex and changeable. It is very important to reveal the characteristics of internal flow field for describing and predicting the phenomena such as water transport solute transport and so on. Based on the regular soil pore network model, Micro-PIV (Micro-scale Particle Image Velocimetry, microscopic Particle Imaging velocimetry) technique was used to analyze the characteristics of fluid movement in pore structure under different Reynolds numbers. LBM method (Lattice Boltzmann Method, was used to analyze the characteristics of fluid movement in pore structure. Lattice Boltzmann method (lattice Boltzmann method) is used to simulate the flow field distribution in pore structure. The results show that the velocity distribution of different pore areas in the micro-scale pore network model is obviously different, the flow field in the midline area is regular distribution, the pore throat is high-speed area, and the velocity of flow is 0.001 mm2. There is a low velocity region near the boundary between two adjacent cylinders in the horizontal direction, and the velocity is less than 0.000 mm2. The velocity field has good symmetry in the direction perpendicular to the direction of the flow direction. In the macroporous region near the upper and lower boundary, the velocity of the fluid can reach 0.003 m/s.LBM. The results of the flow field distribution in the pore network model are in good agreement with the experimental results. The mean root mean square error (RMS) is 0.009 mm2, which indicates that the soil pore network model can effectively simulate soil pores and capture the characteristics of fluid movement on micro-scale. It provides a micro-scale measurement tool for the study of solute transport and reaction in soil pores by using pore network model.
【作者单位】： 河海大学力学与材料学院;中国环境科学研究院;北京师范大学水科学研究院;华南理工大学土木与交通学院;
【基金】：国家自然科学基金项目(41571311)
【分类号】：X53
，
本文编号：2444250
[Abstract]:The pore structure of soil is complex and changeable. It is very important to reveal the characteristics of internal flow field for describing and predicting the phenomena such as water transport solute transport and so on. Based on the regular soil pore network model, Micro-PIV (Micro-scale Particle Image Velocimetry, microscopic Particle Imaging velocimetry) technique was used to analyze the characteristics of fluid movement in pore structure under different Reynolds numbers. LBM method (Lattice Boltzmann Method, was used to analyze the characteristics of fluid movement in pore structure. Lattice Boltzmann method (lattice Boltzmann method) is used to simulate the flow field distribution in pore structure. The results show that the velocity distribution of different pore areas in the micro-scale pore network model is obviously different, the flow field in the midline area is regular distribution, the pore throat is high-speed area, and the velocity of flow is 0.001 mm2. There is a low velocity region near the boundary between two adjacent cylinders in the horizontal direction, and the velocity is less than 0.000 mm2. The velocity field has good symmetry in the direction perpendicular to the direction of the flow direction. In the macroporous region near the upper and lower boundary, the velocity of the fluid can reach 0.003 m/s.LBM. The results of the flow field distribution in the pore network model are in good agreement with the experimental results. The mean root mean square error (RMS) is 0.009 mm2, which indicates that the soil pore network model can effectively simulate soil pores and capture the characteristics of fluid movement on micro-scale. It provides a micro-scale measurement tool for the study of solute transport and reaction in soil pores by using pore network model.
【作者单位】： 河海大学力学与材料学院;中国环境科学研究院;北京师范大学水科学研究院;华南理工大学土木与交通学院;
【基金】：国家自然科学基金项目(41571311)
【分类号】：X53
，
本文编号：2444250
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