对流扩散方程欧拉──拉格朗日方法的B─样条插值格式

利用Ｂ－样条函数．文中发展了一个对流扩散方程欧拉－拉格朗日方法的插值格式．改善了其数值频散性。算例表明，此格式优于一次和二次插值格式。文中给出了Ｂ－样条插值格式的二维及三维推广。     

非线性弥散效应及其对波浪变形的影响

针对Hedges,Kirby和Dalrymple提出的非线性弥散关系的修正式在浅水区存在的较大偏差的问题，给出了一个在整个水深范围内具有单值性的非线性弥散关系。比较可知，它具有在深水与中等水深逼近二阶Stokes波的弥散关系式，在浅水较Hedges,Kirby和Dalymple的修正表达式与Hedges的关系更加吻合的优点，且形式简练，用近似该非线性弥散关系的显式表达式，结合弱非线性效应的缓坡方程，得到考虑非线性弥散影响的波浪变形模型。数值模拟结果表明，用新的非线性弥散关系得到的模型对复杂地形进行模拟的结果和实测结果吻合很好。     

三维海洋溢油预测模型的建立(英文)

提出一个海洋溢油三维物理归宿和输运的动力学综合模型。该模型包含了一系列的数学公式来描述对流、湍扩散、表面扩展、铅直扩散、乳化和蒸发过程。每一公式的建立是独立的并且与相关过程、环境和其它参数相联系。该模型需要输入流场作为输运的媒介 ,这可从感兴趣区域的三维潮和风驱动的流体动力学模型获得。模型用来预测和后报溢油在海洋环境中的归宿和输移 ,可为溢油应急反应和环境影响评价服务。     

海面溢油轨迹的分析与预报

考虑主要分期（Ｍ２，Ｓ２，Ｋ１，Ｏ１，Ｍ４，ＭＳ４）的潮流以及Ｍ２分期的潮汐余流，建立预报潮流场，并考虑海面风力的作用以及油的蒸发和乳化，利用欧拉－拉格朗日方法跟踪油膜的中心点，提出预报油膜的轨迹及其扩散范围。该模型适用于近岸事故溢油的快速预报．     

On the Range of Validity and Accuracy of Boussinesq-Type Models

In this paper the range of validity and comparison of accuracy of three Boussinesq-type models (Madsen and Sφrensen, 1992; Nwogu, 1993; Wei et al., 1995; referred to as MS, NW and WKGS, respectively) are analyzed and discussed. The governing equations are extended to the second-order approximations to keep higher-order nonlinear terms. Two key parameters ε and μ representing wave nonlinear and frequency dispersive properties are used to demarcate the limit of applicability for these three models. The accuracy of predictions by each model is compared by the relative errors with and without hlgher-order nonlinear terms in Boussinesq equations. A numerical model is developed based on one-dimensional Boussinesq equations and applied to the case of waves propagating over a submerged bar. The performance and feasibility of each model are tested against laboratory data.     

Decomposition of the mass transport in narrow estuaries

The mass transport as measured in the Rotterdam Waterway Estuary and in the tidal salinity flume of the Delft Hydraulics Laboratory is analysed to obtain insight into the magnitude of the dispersive mass transport in narrow estuaries. It is found that the magnitude of the dispersive mass transport in the real time one-dimensional advection-diffusion equation varies considerably over the tidal cycle, that the ratio between the magnitude of the dispersive mass transport by the net vertical circulation and by the vertical oscillatory shear in the tidally averaged one-dimensional advection-diffusion equation decreases when the degree of stratification in the flume is decreased, and that the dispersive mass transport in the Rotterdam Waterway and in the tidal salinity flume is affected significantly by the mixing processes at sea near the estuary mouth.     

Analysis of Wave Nonlinear Dispersion Relations

1. Introduction The application of the equation taking into account the weak nonlinearity along with the specificboundary condition is a very important and feasible way to study the wave field influenced by weak non linearity, including refraction, diffraction and shoaling. Results of study show that the method can givesufficient accuracy for practical purposes (Booij, 1981; Hedges, 1987; Choi, 1995; Dingemans,1997; Zhu and Hong, 2001; Li and Yu, 2002; Inan and Balas, 2002; Sun and Ga…     

海南岛新海湾海滩地貌状态与海岸泥沙纵向运动特征

根据１９９０年现场调查及前期观察资料，论述了海南岛新海弧形海湾不同岸段由主要动力驱动过程和海滩地貌结构组成的４种海滩地貌状态，为Ⅰ．隐蔽段消散类型，Ⅱ．脊－沟体系与低潮台地类型，Ⅲ．韵律海滩与砂坝类型，Ⅳ．开敞段消散类型。应用泥沙粒级参数概率模型分析近岸泥沙纵向运动趋势，结果表明，常波况下，沿岸泥沙存在双向运动，湾顶海滩为汇集地带，泥沙纵向运动主趋势为西南向；高能条件下，海岸北段可出现北向泥沙运动     

海洋内波垂向结构的一种数值算法

依据由海上实测资料得到的海水密度、声速及浮性频率随深度的分布等数据，数值求解线性内波垂向问题方程，确定了其主要模态的弥散关系及其特征函数。