【作者】 陶静；

【导师】 汪德爟；

【作者基本信息】 河海大学 ， 环境工程， 2005， 硕士

【摘要】 随着国际贸易、旅游事业以及水产养殖业的发展，便利的水上交通越来越体现出其重要性，船舶的数量和吨位也相应迅猛增长，而这些船舶所排放的含油污水却严重破坏了水体的环境。因而研究油污在水体中的迁移变化成为目前的一个热点问题。 进入水体的油污随着时间的推移会逐步消失，这就是水体的自净作用。石油的这个过程，即物理和化学变化的过程，统称为风化，它包括蒸发、溶解、乳化、分散、沉降、光氧化和生物降解等过程。船舶排放的油污由于排出前就受到振荡而与水混合成乳化状态，因而本文主要研究乳化油在湖面上的扩散作用。 本文应用二维非恒定浅水方程组描述水流流动，以及二维对流—扩散方程描述乳化油的输运扩散，并用二维水流—水质耦合模型来模拟水流流动和乳化油的扩散过程。模型应用无结构网格剖分计算区域，采用黎曼近似解通量差分裂格式(FDS)计算通过各单元边的数值通量，将二维模拟转化为求解一系列局部一维问题，从而模拟出水流过程和相应的油污输运扩散过程。 本文将该模型应用于洪泽湖，计算湖面上的水流过程和油污扩散过程。根据实际情况选择不同工况，讨论了油污在不同工况作用下的扩散的速度、面积等。本文的研究成果可用于湖泊等其它大型水体上的油污扩展过程的预测，为建立浅水湖泊溢油应急预测系统提供了理论基础和实用的技术手段，也为这一方面的继续研究打下了一定的基础。更多还原

【Abstract】 With the development of international trade, tour and aquiculture, convenient traffic on water has become more and more important, which result in the increasing of ship number and tonnage. The oiliness sewage discharged has seriously deteriorated water environment. Therefore, it becomes a popular issue of the transfer and transformation of oiliness wastewater in the water.The process that oiliness wastewater into water disappears as time goes on is called water self-purification. The physical and chemical process of oil transformation is named weathering process, which includes evaporation, dissolution, emulsification, dispersion, sedimentation, photo-oxidation and biodegradation. The oiliness wastewater discharged is disturbed by water, and become emulsified oil. Therefore, the transfer and diffusion of emulsified oil is mainly studied in this thesis.In this thesis, a depth-averaged two dimensional unsteady flow equation is developed to describe water flow, and two-dimensional convection-diffusion equation to describe the diffusion of emulsified oil. A two-dimensional water quantity and water quality coupling model using finite volume method (FVM) is established to simulate water flow and the diffusion of emulsified oil. Flux difference splitting (FDS) algorithm, an approximate Riemann solver, is employed to estimate the normal fluxes across the interface of cells. The two-dimension simulation is transferred into solving a series of local one-dimension problem, which is used to simulate the hydrodynamic process and oil pollution diffusion.The model is applied to the simulation of the movement of water flow and the diffusion of oiliness water on Hongze Lake. Different conditions are chosen according to actual situation, and the velocity and acreage of oil diffusion in different conditions is discussed. The result can be used in predicting the diffusion of oiliness wastewater on lake and other large water body. It also provides theoretical base and technical method for the establishment of Oil Spill Emergency Prediction System on shallow lakes and other large water body, and it has built base for further research.更多还原