【作者】 许雷阁； 林缅；

【Author】 XU Lei-ge,LIN Mian Institute of Mechanics,Chinese Academy of Science,Beijing,100190.

【机构】 中国科学院力学研究所；

【摘要】 波状底床上方的泥沙输移与流场结构直接相关,涡的挟沙作用也已被实验所证实,但是涡结构与底床泥沙输移的定量关系尚需进一步明确,为此本研究采用格子涡(vortex incell)方法对振荡流作用下波状底床上方流场的涡动力特性及悬移质泥沙运动规律做了进一步量化的研究。数值模拟结果表明,悬移质泥沙大部分集中在流场中涡量较大的区域;涡强度值与前人实验及数值模拟结果对比较好,涡挟沙量与涡强度在一个周期内具有相同的发展规律,均在流动转向后达到极大值。一个周期内流场总含沙量存在两个峰值,对应流场流速最大时刻,在前半周期和后半周期,新生涡最大挟沙量与流场总含沙量峰值相比分别达到69%和61%,充分说明了涡对悬移质泥沙运动的重要作用。更多还原

【Abstract】 The transport of sediment on wavy bed is directly related to the flow structures in flow field.And the trapping effect on sands of vortices has already been proved by experiments. Nevertheless,the quantitative relationship between vortex characteristics and the sands amount trapped by the vortex also needs to be further confirmed.For this reason,the vortex dynamics and motion characteristics of suspended sediment in oscillatory flow on a wavy bed are studied by vortex in cell method.By analyzing the results of the numerical simulation,we can arrive at conclusions as follows.The vortex strength and the sands amounts carried by the vortex have the same evolution rules and both reach their maximum after reverse of the flow.The sands amount in the whole flow field has two peaks in a flow period more or less when the flow velocity is at its maximum.The maximum amounts of sands trapped by the newly born vortexes account for 69%and 61%of the peak values of the sand amounts in the whole flow field separately in the first half period and in the latter half of the flow period.This clearly illustrates the significance of vortexes to the transport of suspended sediment.更多还原