作为土壤水蚀过程的主要动力,准确模拟坡面水流过程,对于明确坡面侵蚀机理,构建土壤侵蚀物理过程模型具有重要意义。给出了LatticeBoltzmann方法在坡面水流运动过程中应用的详细步骤,并通过室内人工模拟降雨实验,验证了其有效性。实验结果表明:通过只对时间作多重尺度化,以多尺度分析为手段通过待定系数法来确定平衡态分布函数,以宏观上边界条件作为限制条件,用平衡态分布函数代替上边界结点上的分布函数,及通过分布函数外推格式来确定下边界结点上的分布函数的处理方法,可将Lattice Boltzmann法成功应用于坡面流运动方程的求解,各场次降雨的地面径流深误差均在±11%以内。
As the main reason for soil water erosion, the overland flow process should be simulated precisely to understand the mechanism of slop soi[ erosion process. Developed based on the kinetic theory, Lattice Bohzmann method has advantages of concise programming, parallel computing and complex geometric adaptability, etc. So its application in field of fluid motion becomes more and more extensively. The detailed steps about applying Lattice Boltzmann method to the movement of overland flow was given firstly, and then its validity was verified through artificial simulated rainfall experiment. The results indicate that if the time is processed by multi-scale approach and the space is not, the equilibrium distribution function is determined by the method of undetermined coefficients and multi-scale analysis, the distribution function about nodes of the upper boundat3~ is replaced by the equilibrium distribution function through regarding the macroscopic upper boundary conditions as limiting conditions, and the distribution function about nodes of the lower boundary is set by extrapolation format of distribution function, Lattice Bohzmann method will successfully become a motion equation solver. The errors of runoff depth are within±11%.