【作者】 徐海珏；

【导师】 白玉川；

【作者基本信息】 天津大学 ， 港口、海岸及近海工程， 2007， 博士

【摘要】 河流弱动力过程作为现代河流动力学中一部分,具有举足轻重的地位。它不仅是现代河流动力学研究的基础,对未来河流动力学的发展有奠基性的影响;而且是河流动力学未来发展不可缺少的重要部分。为了深入理解河流、泥沙、水流相互作用机理,本文仅就河流动力学研究中的河流弱动力过程做了广泛而深入的研究。本论文参考湍流研究和突变理论的基本研究方法,分别从河流过程各个方面建立模型进行理论及实验方面的研究,具体内容包括:明渠河流非平整床面上的水流稳定性特征分析、悬移质的存在对明渠流稳定性特征的影响、河道推移质对床面发展的影响以及天然明渠中沙纹、沙垄的形成机理分析等。考虑了多方面的研究内容,包括:明渠层流在不规则床面影响下的稳定性特征、明渠流在悬移质影响下的稳定性调整、推移质运动过程的非线性动力以及运动学特征、以及平整床面上沙纹以及沙垄的形成和发展的非线性演化过程等。在这些理论研究的基础上,第七章给出了利用声学多普勒流速仪测量出的明渠流的水流结构和流动特征,并得到了水流结构对床面发展过程的影响等结果。经过验证,理论中的部分结果能较好地解释实验中出现的部分现象。本论文的主要研究内容——河流弱动力过程的基础理论,不仅对于现代河流动力学的研究有开创性的研究意义,而且对于湍流理论在水力学中的应用有着极其重大的意义。论文中泥沙运动规律的研究,不仅是明渠床面形态研究的基础,也是人们对风成沙丘的形成机理深入了解的基础。更多还原

【Abstract】 The“weak”dynamic process of river is in a very important position, which is as a part of the study of the modern river dynamics. It is not only the base of the modern river mechanics study, which can make great contributions to the future development of it; but also has become one of the most important parts of it.The“weak”dynamic process of river is studied extensively and deeply in this paper to make a good understanding on the interaction principles of the river, sediment and the flow. The theoretical model on the various aspects of the river process is established to study the dynamics of it by using the methods of mutation and mathematic theory that always used in the turbulent study, which includes: the stability characteristics of the open channel flow on an uneven bed, the effects to the stability characteristics of the laminar flow in open channel by the suspended load, the effects to the development of the bed form by the bed load in the river and the principles of the dunes formation in the open channel. And something in this paper is discussed in detail, for instance: the structure of the open channel flow on the irregular bed, the stabilized effects of the suspended load, reasons that caused the nonlinear dynamic and kinematic characteristics of the particles of the bed load, and the nonlinear evolution principle of the dunes. On the basis of these, the flow characteristics are measured by the ADV in Chapter 7, and finally, some results about the effect of the flow structure on the bed for development are got. And it is proved that some of the phenomenon can bed well explained by the some of the theoretic results.The main contents of this paper—the basic theory of the“weak”dynamic process of the river, has the contributions not only to the modern river dynamic but also to the application of the turbulence theory to the hydraulic. And the study of the sediment movement law is basis not only to the study of the bed form in the open channel, but also to the further understanding to the aeolian dune formation.更多还原