沿岸流不稳定运动研究进展

Research development of the shear instability of longshore currents

沿岸流不稳定运动目前已成为一个研究热点,对于沿岸流不稳定的研究对于近岸泥沙、污染物输移以及海岸养护等都有很重要的意义。本文详细介绍了沿岸流不稳定运动的研究进展,具体包括沿岸流不稳定运动现场以及实验室实验研究进展,沿岸流线性不稳定理论,非线性不稳定理论以及沿岸流不稳定运动产生的其它理论分析。结果表明国外对于该问题的研究(主要是有关不稳定理论方面)已经取得很多成果,但国内目前很少,并且现在对沿岸流不稳定研究比较成熟的理论基础是不稳定理论,该理论都假定增长率最大的不稳定模式决定着沿岸流的波动特性。但对于多模式不稳定运动的研究还基本没有,对于沿岸流不稳定运动三维特性的研究(包括数值研究及实验研究)也基本没有报道。所以这两个方面可能是以后对该问题研究的重要方向。

Recently,the research on the instability of longshore currents becomes the hotspot.The study on this problem has great effects on the sediment and contamination transport and coastal defences.In this paper,the development of shear instability of longshore currents is reviewed.Field and laboratory experiments on the shear instabilities,linear instability theory and non-linear instability theory and other generation mechanisms of the instability of longshore currents are summarized.It indicates that much more achievements are made than the domestic research.The popular theory for the instability of longshore currents is the linear shear instability theory.It is assumed that the instability mode with the largest growth rate dominates the instability of longshore currents.The research on the multi-mode of the instability of longshore currents has not been carried out recently.And the studies on three dimension characters of the instability of longshore currents including numerical and laboratory aspect haven＇t carried yet.Therefore,these two may be the major topics on the instability of longshore currents before long.