沙纹床面上波流共同作用的数值模拟

Numerical simulation for joint action of wave and current on rippled sea bed

海滨地区广泛存在涡动沙纹,它很大程度上决定着波浪衰减和泥沙运动。本文建立了描述波浪、水流共同作用下底层流动特性的立面二维数值模型。模型成功模拟了波浪、水流共同作用下底层分离涡随时间、空间变化的动力特性,文中还进一步对波浪、水流不同对比情况下的涡动力特性及分离涡尺度和紊动特性进行了讨论。

Vortex ripples widely exist in coastal area and greatly control the attenuation of wave and movement of sediment. The flow structure around the vortex ripples can be modeled as a 2-D flow due to the geometry of the flow boundary. In this paper, a 2-D large-eddy-simulation method (LES) was used to predict the flow structure and the dynamic characteristics of vortex in the sea bed under the joint action of wave and current. The result gives the whole process of the formation, evolvement and disappearance of vortex. Furthermore, the dynamic characteristics of vortex, its scale and turbulent characteristics of separated vortex under different combinations of wave and current were investigated.