Diffusive and dispersive processes in the aquatic environment and the modeling methods

所进行的研究涉及各种自然水环境的扩散和分散过程。通过讨论会议，对参与研究者的研究进行了比较，并对扩散和分散过程提出了总体看法。各研究者的研究成果总结如下：1 .利用k - epsilon湍流模型对紊流壁面羽流进行了分析，得到了该流动的湍流扩散系数。2. 建立了海湾、湖泊等封闭水体的垂直湍流扩散系数公式，并对结果进行了验证。3. 用物理模型和数学模型研究了浑浊物在水库中的扩散和分散。4. 推导了复合明渠流的湍流扩散系数和色散系数，并进行了实验验证。5. 开发了模拟海洋悬浮物运动的计算机程序，进一步研究了扩散和平流输运的相对重要性。开发了海洋扩散的二维有限元和三维FDM仿真程序。6. 提出了一种新的平流项有限差分格式，使其具有很高的精度。同时，提出了一种新的海湾一维色散系数公式，并用多组现场数据进行了验证。7. 在拉格朗日公式的基础上，利用收集到的大量数据，研究了河流的一维色散系数。同时，提出了一种利用一般自然坐标系计算河流中二维扩散方程的新方法。8. 利用东京湾的实测资料，对海上湍流扩散系数进行了分析。通过对实测数据的收集和分析，给出了一个较好的海湾水平湍流扩散系数的估计。同时，提出了一种求得海湾湍流扩散系数相似度的方法及其问题。10. 提出了一种通过改变海峡地形来改变海峡水流结构的新方法，并用水力学模型进行了验证。少

The research study conducted is concerned with diffusive and dispersive processes of various kinds of natural water environment. Through discussion meetingseach study by the participating investigators was compared and the overall view on the diffusive and dispersive processes has been presented. The research results obtained by each investigator are summarized as follows : l. The turbulent wall plume was analyzed with the aid of the k - epsilon turbulence model and the turbulent diffusivity of this flow was obtained. 2. The vertical turbulent diffusivity of the enclosed body of water such as a bay or a lake was formulated and the result was verified. 3. Diffusion and dispersion of turbid matter in a reservoir was studied by both physical and mathematical models. 4. The turbulent diffusivity and dispersion coefficient of composite open channel flow were formulated and verified experimentally. 5. A computer program of simulating the movement of suspended material in the sea was develope … More d to study the relative importance of the diffusive and advective transport. Also, two dimensional FEM and three dimensional FDM simulation programs of the diffusion in the sea were developed. 6. A new scheme of finite difference of the advective terms was developed to give the very high accuracy. Also, a new formulation of the one dimensional dispersion coefficient of the bay was proposed and tested with a number of set of field data. 7. The one dimensional dispersion coefficient of rivers was studied on the basis of the Lagrangian formulation and large number of data collected. Also, a new calculation method of the two dimensional diffusion equation in rivers was formulated using the general natural coordinate system. 8. The turbulent diffusivity in the sea was analyzed using the field data obtained in Tokyo Bay. 9. A good estimate of the horizontal turbulent diffusivity of bays was presented collecting and analyzing the field data. Also, a method and its problem of attaining the similarity of turbulent diffusivity in the bay was presented. 10. A new method of changing the flow structure by modification of the topography of the straits was proposed and demonstrated using the hydraulic model. Less