波浪影响下近底高浓度泥沙水运动的动力学模拟

Dynamics Simulation of Bottom High Sediment Sea Water Movement Under Waves

波浪影响下的近岸海底泥沙水运动,特别是近底高含沙率泥水层,对泥沙的再悬浮和沉淀起着至关重要的作用.假定底部高浓度泥沙水为牛顿流体,利用N-S流体运动理论,采用VOF法追踪水-气界面和水-泥沙水的相界面运动,模拟了波浪作用下泥水层内的动力学响应.结果表明:泥水层的响应与主体海水波动不同,为研究底部泥沙再悬浮和底部条纹形成打下了基础;VOF法能较好地追踪水-气和水-泥沙水相界面运动的多相界面问题;同时界面间存在互相作用,即水-气界面波动对水-泥沙水界面有较大影响,而水-泥沙水界面对水-气界面影响很小.

The movement of bottom sediment sea water under the influence of water waves, especially that of high sediment water layer close to sea bottom is important to the resuspension and settlement of sediment. Supposing the high sediment sea water a Newtonian fluid, based on N-S theory, the movement of interfaces of airwater and water-sediment water was tracked by VOF method. The velocity field of sediment water was simulated by considering the influence of water waves. The results show that the movement of sediment water is different from that of sea water which is a solid basis for understanding the resuspension and settlement of sediment and the formation of bottom stripe; VOF method can trace the movement of two interfaces simultaneously; the movement of air-water interface has strong influence on that of water-sediment water interface, while the effect of water-sediment water interface movement on the air-water interface is not obvious.