NONLINEAR INTERFACIAL CAPILLARY-GRAVITY WAVES IN SHEAR FLOW

In this paper,the capillary-gravity solitary waves in a two-fluid system withshear flow are theoretically investigated.Three cases are considered.For the first case(the nor-mal case),the KdV equation,with the effect of shear flow being taken into account,is derivedand it is found that there may exist single mode travelling solitary waves,slowly travelling soli-tary waves and even more slowly travelling solitary waves at some shear flow conditions.Thesecond case considered is that the fluid system is at the first kind critical condition.The modifiedKdV equation in which the cubic nonlinearity balances the dispersion is obtained and the solutionof mKdV solitary wave in shear flow is put forward.The third case is that the fluid system is atthe second kind critical condition.The generalized KdV equation with the effect of shear flowconsidered is given.It is shown that there exist normal and oscillatory solitary waves and thecondition of existence of oscillatory solitary waves are also presented.     

关于非线性浅水波理论中的孤立波解

本文在[1]的基础上,详尽地得到了Boussinesq方程和KdV方程的孤立波解,并对波高和波形进行了细致的分析。为了更好地比较,本文还给出了高阶摄动的孤立波解。     

GENERATION OF NONLINEAR INTERNAL WAVES ON CONTINENTAL SHELF

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｅｒｎａｌｔｉｄａｌｉｎｔｅｒａｃｔｉｏｎｗｉｔｈｂｏｔｔｏｍｆｅａｔｕｒｅｓａｐｐｅａｒｓｔｏｂｅｔｈｅｄｏｍｉｎａｎｔｍｅｃｈａｎｉｓｍｆｏｒｇｅｎｅｒａ ｔｉｏｎｏｆｔｈｅｃｏｈｅｒｅｎｔｏｃｅａｎｉｃｉｎｔｅｒｎａｌｗａｖｅｓｔｈａｔａｒｅｏｂｓｅｒｖａｂｌｅｗｉｔｈＳＡＲ ,ｃｌｏｓｅｒｔｏｓｈｏｒｅ ,ｒｉｖｅｒｉｎｅｏｒｇｌａｃｉａｌｉｎｔｒｕｓｉｏｎａｎｄｃｏｎｔｉｎｅｎｔａｌｂｒｅａｋｐｒｏｖｉｄｅｓｅｃ ｏｎｄａｒｙｇｅｎｅｒａｔｉｎｇｍｅｃｈａ…     

FISSION LAWS OF INITIALLY INTERFACE SOLITARY WAVES IN TWOLAYER OCEAN

A 2 D KdV equation of two-layer stratified ocean with 2-D topography is recapitulated in the present paper. Based on a reduced version of this 2-D KdV equation, the fission laws of the initially internal solitary waves are studied by means of numerical calculation. From the numerical results, it is shown that the initially interface solitary waves can fission on the continental slope like the initially surface solitary waves and the fission process is a significant generating mechanism of internal interface soliton packet on the continental shelf.     

具表面张力（I.Bond数大于1／3）的流体流过地形的共振流动

本文讨论了具表面张力作用下不可压缩无粘流体流过地形障碍物的共振流动。采用摄动方法，本文导出了一个新的方程，具负色散的ｆｋｄｖ方程，数值结果表明该情形可激发出下游下凹孤立波串，这个结果有待进一步的实验验证。     

NUMERICAL STUDY OF SOLITARY WAVE FISSION OVER AN UNDERWATER STEP

Solitary wave fission over an underwater step is numerically investigated. The numerical model is based on the enhanced Boussinesq equations, which appropriately represent both the nonlinearity and dispersivity of surface water waves. The finite difference method defined on the staggered grid in space with an implicit scheme for time stepping is employed for the numerical solution of the governing equations. It is demonstrated that Boussinesq type equations, though they are vertically integrated, can describe the details of the solitary wave fission process with very good accuracy. Numerical results of the reflected and transmitting wave heights, the number of solitons emitted from the transmitting wave and their amplitudes all agree very well with the analytical solution derived from KdV equation by virtue of a linear long wave approximation in the vicinity of the underwater step.     

NONLINEAR WATER WAVES IN LAGRANGIAN COORDINATES:SHALLOW FLUIDS

ＮＯＮＬＩＮＥＡＲＷＡＴＥＲＷＡＶＥＳＩＮＬＡＧＲＡＮＧＩＡＮＣＯＯＲＤＩＮＡＴＥＳ：ＳＨＡＬＬＯＷＦＬＵＩＤＳＴｉａｎＭｅｉ；ＺｈｕＹｏｎｇ（ＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓａｎｄＭｅｃｈａｎｉｃｓ，Ｓｈａ...     

有限深两层流体中内孤立波传播演化理论模型研究

该文对Choi和Camassa给出的一个内孤立波方程模型中的系数进行了修正,并给出了基于方程的内孤立波定态解表达式,将其称为内孤立波me Kd V理论解,进而采用有限体积/有限差分混合方法数值求解内孤立波的三类(Kd V、e Kd V和me Kd V型)非线性传播演化方程,分别以内孤立波的Kd V、e Kd V、MCC和me Kd V定态解作为初始输入波,研究其非线性传播演化特性,并获得其适用性条件。结果表明,三类非线性传播演化方程,只适合于相应内孤立波定态解初始波的定态传播,而对其他定态解初始波将发生波形变形、分裂等非线性现象。在此基础上,定量地给出了三类非线性传播演化方程的适用性条件,为采用何种非线性方程来研究实际海洋中内孤立波的传播演化问题提供了理论依据。     

二维平行壁面剪切流动的转捩与混沌模型

本文利用约化摄动方法，从理论上研究了二维平行壁面剪切流动的转捩与混沌现象，得到了描述二维平行壁面流动中的小振幅Ｔ－Ｓ波的演化方程为Ｋｏｒｔｅｗｅｇ－ＤｃＶｒｉｅｓ－Ｂｕｒｇｃｒｓ方程，反映Ｔ－Ｓ波衰减或增长率的参数为ＫｄＶ－Ｂｕｒｇｅｒｓ方程中的耗散系数Ｖ１与色散系数δ的比值ｖ１√δ，ｖ１和δ由流场结构决定的。当Ｔ－Ｓ波振幅被放大到一定程度后将受到的自由流中的高次或亚谐波的激励。经过分叉而进入混沌     

基于参数优化的非饱和尾矿砂渗流场解析解研究

为研究渗流稳定后非饱和尾矿砂含水率的空间分布规律,从而为更准确的尾矿坝安全评估提供基础性资料,首先从非饱和渗流的Richards方程出发,在对方程形式和求解区域简化之后,通过解析的方法得到了含水率空间分布公式,公式具有无穷级数的形式。然后通过自行设计的仪器进行了尾矿砂二维非饱和渗流试验,得到了含水率在水平和竖直方向上的分布规律。试验结果表明:在两个方向上含水率的分布都近似服从指数函数。最后在结合测量数据的基础上利用混沌粒子群优化算法(CPSO)编制程序算出求解方程过程中引入的常数,并利用所得模型计算了测量点处的含水率。通过对比发现含水率理论值与实测值较为相近。     

三层流体系统中初始扰动和密度比对孤立波生成的影响

本文讨论了初始扰动和密度比对三层流体系统中孤立波生成的影响出发点是所导得的ＫｄＶ方程和散射反演理论的结果。分析结果表明，增加初始扰动的高度和宽度会生成更多的孤立波，这与Ｍａｘｗｏｒｔｈ＾［３］的实验结果一致；此外，在较弱分层情形，密度比对孤波生成的影响极小，而在较强的分层情形，其影响较大。     

流对浅水波在缓变地形上传播的影响

孤立波在缓变地形上传播,将发生折射。在这一过程中加入流的影响将使传播过程更加复杂。本文采用有流影响的变系数二维KdV方程来描述这一现象。通过数值计算,文中给出了孤立波在斜坡海岸、水下圆岛等两种地形上有流及无流情况下,和旋涡流场中的折射的时间历程。并讨论了流对孤立波分裂、折射及传播速度的影响。     

Modeling and Combined Application of Orthogonal Chaotic NSGA-II and Improved TOPSIS to Optimize a Conceptual Hydrological Model

Conceptual rainfall-runoff modelling is a widely-used approach for rainfall-runoff simulation in streamflow forecasting. The objective of this paper is to introduce an improved non-dominated sorting genetic algorithm-II (NSGA-II) for multi-objective automatic calibration of a hydrologic model. The orthogonal design based initialization technique is exploited to produce a more uniformly-distributed initial population. At the same time, a chaotic crossover operator as well as a chaotic mutation operator are presented to avoid trapping into local minima and to obtain high quality solutions. Finally, a multi-criteria decision-making (MCDM) approach combing Shannon entropy weighting method and an improved technique for order preference by similarity to ideal solution (ITOPSIS) based on projection is introduced to prioritize the Pareto optimal solutions and select the comprehensive optimal solution as a follow-up step. Hydrological data from two river basins named the Leaf and Muma River basins are exploited to test the ability of the orthogonal chaotic NSGA-II (OCNSGA-II) for solving the multi-objective HYMOD (MO-HYMOD) problem. The results demonstrate that the OCNSGA-II can obtain better-distributed Pareto optimal front and thus can be exploited as an effective alternative approach for the multi-objective automatic calibration of hydrologic model.     

CHAOTIC ANALYSIS OF SUBHARMONIC RESONANT WAVES IN UNDAMPED AND DAMPED STRINGS

ＣＨＡＯＴＩＣＡＮＡＬＹＳＩＳＯＦＳＵＢＨＡＲＭＯＮＩＣＲＥＳＯＮＡＮＴＷＡＶＥＳＩＮＵＮＤＡＭＰＥＤＡＮＤＤＡＭＰＥＤＳＴＲＩＮＧＳ￥ＡｌｂｅｒｔＣ．Ｊ．Ｌｕｏ，ＲａｙＰ．Ｓ．Ｈａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈａｎｉｃａｌ＆Ｉｎｄｕｓｔｒｉａ...     

Chaotic Evolutionary Algorithms for Multi-Reservoir Optimization

The water sharing dispute in a multi-reservoir river basin forces the water resources planners to have an integrated operation of multi-reservoir system rather than considering them as a single reservoir system. Thus, optimizing the operations of a multi-reservoir system for an integrated operation is gaining importance, especially in India. Recently, evolutionary algorithms have been successfully applied for optimizing the multi-reservoir system operations. The evolutionary optimization algorithms start its search from a randomly generated initial population to attain the global optimal solution. However, simple evolutionary algorithms are slower in convergence and also results in sub-optimal solutions for complex problems with hardbound variables. Hence, in the present study, chaotic technique is introduced to generate the initial population and also in other search steps to enhance the performance of the evolutionary algorithms and applied for the optimization of a multi-reservoir system. The results are compared with that of a simple GA and DE algorithm. From the study, it is found that the chaotic algorithm with the general optimizer has produced the global optimal solution (optimal hydropower production in the present case) within lesser generations. This shows that coupling the chaotic algorithm with evolutionary algorithm will enrich the search technique by having better initial population and also converges quickly. Further, the performances of the developed policies are evaluated for longer run using a simulation model to assess the irrigation deficits. The simulation results show that the model satisfactorily meets the irrigation demand in most of the time periods and the deficit is very less.     

周期叠加外延—最近邻抽样回归组合模型在韩江流域年径流预测中的应用

为提高年径流预报精度,尝试将周期叠加外延法与最近邻抽样回归模型结合,用韩江流域潮安站年径流系列作试验,结果表明组合模型预测合格率比单一周期叠加外延模型高,预测效果较好.     

ANALYTICAL AND APPROXIMATE SOLUTION FOR SPHERICAL SYMMETRY DISPERSIVE TRANSPORT IN POROUS MEDIA

Spherical symmetry convective-dispersive transport of a tracer or contaminant from continue and slug injection well in semi-infinite porous media is of significance,especially for the tracer test in huge thick formation.The partial equation describing the transport process belongs to confluent hypergeometric equation.With variable substitution and Laplace transform,the partial equation may be coverted Weber equation and it's solution is represented by parabolic cylinder function.We found the analytical solution by analytical inversion.Besides,we also obtained the early-time and late-time approximate solution.In the paper we compared these solutions and investigated the basic characteristics of concentration distribution and change.In early-time and late-time the approximate solution is of significance.     

自适应混沌差分进化算法在梯级水库优化调度中的应用

介绍了一种基于自适应混沌映射的差分进化算法,该算法采用混沌映射的方式产生初始种群,并综合考虑算法迭代进度和个体进化程度两个因素,对缩放因子进行动态调整以促进算法全局搜索和局部寻优的平衡。同时,在算法进化的不同阶段采取不同尺度的扰动策略,进一步提高算法的再搜索能力。将该算法应用于某梯级水库发电调度的研究中,通过实例计算,并与基本差分进化算法、模拟退火算法相比,得到了更优的全局最优解,验证了该算法的可靠性和实用性。     

一类流体动力方程的时间周期解(英文)

讨论一类带周期边界条件的流体动力方程,利用Galerkin方法构造时间周期解的近似解序列,通过先验估计和Leray-Schauder不动点定理证明近似解的收敛性,从而得到了流体动力方程时间周期解的存在性.     

论混沌理论与水文预测问题

简述了混沌理论的基本概念，结合水文预测问题介绍了混沌理论应用的基本方法和步骤。在水文预测中，应用混沌分析方法需解决相空间重构、时间序列的混沌性识别和混沌时间序列预测等关键技术。