首页|多孔介质固体颗粒粒径特征及膨胀作用对地下水孔隙尺度流场特征的影响

多孔介质固体颗粒粒径特征及膨胀作用对地下水孔隙尺度流场特征的影响

Influence of Particle Size Characteristics and Swelling of Solid Particles in Porous Media on Pore-Scale Flow Field Characteristics of Groundwater

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地下水孔隙尺度流场特征的研究对于深入理解地下水渗流、溶质运移具有重要意义.目前固体颗粒粒径特征不同时介质微观结构对孔隙尺度流场的影响尚不清楚.基于迭代重排算法构建了固体颗粒粒径分布特征、膨胀程度不同的多孔介质,基于此研究了固体颗粒平均粒径、粒径方差及膨胀作用对地下水流场特征的影响.结果表明,在介质孔隙率相同的条件下,固体颗粒平均粒径、粒径方差对多孔介质中流速的非均质性、速度概率密度分布等流场特征影响较小.而在同一介质中,当固体颗粒膨胀引起孔隙率减小时,平均粒径较小幅度的变化就会对以上流场特征产生显著影响.例如当固体颗粒膨胀程度增强时,粒径小幅度的增大,就会导致流场中优势流区和不流动区比例同时大幅度增加,流场非均质性显著增强,流速概率密度分布更加发散.
The study of groundwater pore-scale flow field characteristics is of great significance for the in-depth understanding of groundwater seepage and solute transport. However,the effect of the microstructure of porous media with different particle size characteristics on the pore-scale flow field is yet unclear. This paper constructs porous media with different particle size distribution characteristics and swelling degrees of solid particles using an iterative rearrangement algorithm. On this basis,the effects of the average particle size,particle size variance and solid particle swelling degrees on the characteristics of groundwater flow field are investigated. The results show that under the condition of the same porosity of the porous media,the mean particle size and particle size variance of solid grains have less influence on the flow field characteristics such as the heterogeneity and probability density distribution of flow velocity in porous media. However,in the same medium,when the expansion of solid particles causes a reduction in porosity,a smaller change in average particle size can have a significant effect on the above flow field characteristics. For example,when the expansion degree of solid particles increases,a slight increase in particle size will lead to a large rise in the proportion of the dominant flow area and the stagnant region at the same time,a significant enhancement in the heterogeneity of flow field,and a significant growth in the divergence degree of the flow velocity probability density distribution.

groundwater flow field characteristicsporous mediasolid particle sizepore scalenumerical simulationhydrogeology

侯玉松、刘苏、辛虎、吴吉春、胡晓农、邢立亭

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济南大学水利与环境学院,山东济南 250022

南京大学地球科学与工程学院,江苏南京 210023

地下水流场特征 多孔介质 固体颗粒粒径 孔隙尺度 数值模拟 水文地质学

国家自然科学基金项目山东省自然科学基金项目山东省高校院所创新团队项目国家自然科学基金项目济南大学博士基金项目济南大学科技计划基金项目

42002257ZR2020QD1232018GXRC01241772257XBS1911XKY1922

2024

地球科学
中国地质大学

地球科学

CSTPCD北大核心
影响因子:1.447
ISSN:1000-2383
年,卷(期):2024.49(7)