基于SPH-SWE方法对河流保守型污染物扩散的模拟

Simulation of conservative pollutant diffusion in rivers based on SPH-SWE method

为了追踪河流中污染物的迁移轨迹与浓度分布规律,采用光滑粒子流体动力学(SPH)和浅水波方程(SWE)对保守型河流污染物的扩散过程进行模拟,通过对输运方程的离散求解,模拟了一维、二维均匀流和经典溃坝案例并对实际地形进行预测。结果表明:一维、二维均匀流以及溃坝模拟结果和解析解一致,且能避免浓度负值的出现,验证表明SPH-SWE模型具有很好的稳定性。本研究预测了南门峡水库溃坝后污染物浓度分布在河道中间位置,其峰值达到0.0756 kg/m^(3),说明计算结果合理,证明了此模型具有较强的预测能力,可预测实际河流中保守型污染物扩散分布情况。

In order to track the migration trajectory and concentration distribution of pollutants in the river,Smooth Particle Hydrodynamics(SPH)and Shallow Water Wave Equation(SWE)are used to simulate the diffusion process of conservative river pollutants.Through the discrete solution of the transport equation,one-dimensional,two-dimensional uniform flow and classic dam break cases are simulated and the actual terrain is predicted.The results show that one-dimensional and two-dimensional uniform flow and the results of dam break simulation are consistent with the analytical solution,and the occurrence of negative concentration values can be avoided,which verifies that the SPH-SWE model has good stability.It is predicted that the concentration of pollutants is distributed in the middle of the river channel after the dam break of Nanmenxia Reservoir and its peak value will reach 0.0756kg/m^(3),indicating that the calculation results are reasonable and proving that this model has strong predictive ability which can predict the diffusion distribution of conservative pollutants in actual rivers.