黏性泥沙不等速沉降絮凝的格子Boltzmann模拟

Lattice Boltzmann simulation for flocculation of cohesive sediment due to differential settling

建立黏性泥沙运动的三维格子Boltzmann模型,对黏性泥沙不等速沉降絮凝过程进行全尺度直接数值模拟,从微观角度分析了泥沙颗粒不等速沉降形成的絮团特性和絮团成长过程。模拟结果与已有实验结果一致。模拟结果还表明,不等速沉降时不同泥沙浓度条件下形成的絮团若大小相近则沉降速度接近,但泥沙浓度对水体中泥沙总体平均沉速有明显影响,泥沙浓度越高,泥沙平均沉速越大,主要是因为泥沙浓度越大,颗粒之间越容易发生碰撞而形成更大、更多的絮团。

A 3-D numerical model for flocculation dynamics of cohesive sediment based on Lattice Boltzmann method was presented. The fiocculation process due to differential settling was simulated in full scale. The floc properties and growth process were explained from the view point of mesoscale. The simulation results agree with the experimental data given by predecessors. It is found that the flocs with similar sizes formed in different sediment concentrations have similar velocities of differential settling, but ...