波浪作用下悬移质泥沙运动的两相流数值模型

该文采用基于水沙两相紊流的数值模型对波浪作用下的悬移质泥沙运动进行研究。基本方程中将水相和颗粒相通过相间作用力进行耦合,合理地考虑了相间相对运动的影响。数值计算方法为有限体积法,对流项处理利用了三阶精度的QUICK格式,离散方程组求解采用的是TDMA迭代方法。计算得到的悬移质泥沙垂线时均计算值与不同尺度的水槽实验数据吻合很好,表明数学模型及其计算方法对于低浓度水沙两相问题是合理的。该研究还探讨了悬沙浓度、泥沙沉降速度以及各种相间作用力随时间的分布规律。

Numerical study on suspended sediment transport under waves

Based on a numerical model of two-phase flows, the suspended sediment transport under waves is studied. An advanced mathematical model is employed by accurately considering relative motion and various forces between fluid phase and sediment phase. Numerical discretization is based on finite volume method. QUICK scheme of the third-order accuracy is used to represent the convection term, and TDMA iteration method is adopted for solving algebraic equations. The time-averaged calculation results of sediment concentration along vertical direction are shown to be in good agreement with experimental measurements. It indicates that the model and calculation method presented in this paper are suitable for water-sand flow with low concentration. The variation of the sediment concentration profile within a wave period is investigated. The effects of wave phase on various forces between fluid phase and sediment phase are also demonstrated.