基于FLUENT土壤养分渗流扩散的数值模拟研究

Research on Numerical Simulation of Soil Nutrient Seepage and Diffusion Based on FLUENT

通过模拟降雨装置试验测定了土壤的渗透系数,并借助CFD-PDE耦合,采用离散元软件FLUENT的流体模拟功能研究了磷酸二氢钾溶液在土壤渗流过程中渗流速度和有效扩散系数随土层深度的变化规律。结果表明:在不同水头下渗透系数的变化基本上都呈下降趋势,供试土壤的渗透率随土层深度的增加而降低;磷酸二氢钾溶液在中心点以下0.02 m处的渗流扩散能力最强,且随着土层深度加深和到中心点距离的增加呈辐散性减弱。

The soil permeability coefficient was determined by simulating the rainfall device test.With the help of CFD-PDE coupling and the fluid simulation function of discrete element software FLUENT,the change law of the seepage velocity and effective diffusion coefficient of potassium dihydrogen phosphate solution with the depth of the soil layer during the seepage process was studied.The results show that the permeability coefficient under different water heads is basically the same and shows a downward trend.The permeability of the tested soil decreases with the increase of soil depth.The potassium dihydrogen phosphate solution is obtained by simulating the percolation of potassium dihydrogen phosphate solution in the soil.Seepage diffusion is the strongest at 0.02 m below the center point,and the divergence decreases as the depth of the soil layer and the distance from the center point increase.