沙垄和沙波非线性演化特征研究  

Study on the Nonlinear Evolution of Sand Dunes and Antidunes

作　　者：张贺[1,2] 邹志利 徐杰[1,2] ZHANG He;Zou Zhi-Li;XU Jie(1.Dalian University of Technology;The State Key Laboratory of Coastal and Offshore Engineering,Dalian 116021,.China)

机构地区：[1]大连理工大学,辽宁大连116024 [2]海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《海岸工程》2018年第2期61-72,共12页Coastal Engineering

基　　金：国家自然科学基金项目--海岸自我恢复能力研究(11272078)

摘　　要：沙垄和沙波是陆地河流和海岸河口的常见水底泥沙堆积形态,其形态和演变涉及水流和地形之间很强的非线性作用,导致其产生、演化和形态特征的研究存在较大难度,所以沙垄和沙波的演化特征一直是河流动力学和海洋科学中重要研究课题。采用特征线方法给出了沙垄和沙波剖面形态特征和演化速度随Froude数和其幅值的变化特征,分析了地形坡度项和水底摩擦项对沙垄和沙波演化特征的影响,结果表明,沙垄和沙波剖面的演化受地形演化方程的非线性影响较大,后者所导致的剖面形态都是沿顺流方向倾斜,其不因沙波是逆流迁移而改变,这与线性理论的结果不同。该演化特征也受到Froude数,水底坡度和水底摩擦的显著影响。这些结果可以为沙垄和沙波的数值模拟分析提供理论参考。Sand dunes and antidunes are bottom sediment accumulation forms commonly observed in rivers and estuaries. Their morphology and evolution involve strong nonlinear interaction between water flow and topography so that it is difficult to study their generation,evolution and morphological features. As a result,the evolution characteristics of the sand dunes and antidunes have been becoming an important subject in river dynamics and marine science. In the present paper,a characteristic line method is applied to give the profile morphological characteristics and the variation of evolution rate with froude number and amplitude of the sand dunes and antidunes. And then,the effects of the bed slope and bottom friction on the evolution of sand dunes and antidunes are analyzed.The results show that the evolution of the profiles of sand dunes and antidunes are more strongly influenced by the nonlinear terms in the topography evolution equation. The profile forms caused by the latter are all tilted along the downstream direction,which does not change because of the countercurrent migration of antidunes. This is different from the result given by the linear theory. Such evolution feature is also greatly affected by the Froude number,the bed slope and the bottom friction. The present study can provide theoretical references for the numerical simulation of sand dunes and antidunes.

关 键 词：沙垄 沙波 非线性 水流 

分 类 号：TV142[水利工程—水力学及河流动力学] P737[天文地球—海洋地质]