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浅水波方程模型与奇非线性行波方程解的动力学行为及精确的参数表示:动力系统方法
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作者 李继彬 《四川师范大学学报(自然科学版)》 CAS 2024年第4期451-468,共18页
首先,介绍在重力作用下,无旋、无黏性和不可压缩的流体的表面波传播的一维(或两维单向)浅水波运动的各种不同模型(PDE),这些模型对应的行波系统一般是奇平面动力系统.其次,用著名的广义Camassa-Holm方程作为例子,通过对应的行波系统的... 首先,介绍在重力作用下,无旋、无黏性和不可压缩的流体的表面波传播的一维(或两维单向)浅水波运动的各种不同模型(PDE),这些模型对应的行波系统一般是奇平面动力系统.其次,用著名的广义Camassa-Holm方程作为例子,通过对应的行波系统的精确解来研究该方程的尖孤子、周期尖波、伪尖孤子、伪周期尖波及有界破缺波解的存在性.第三,应用动力系统分支理论和奇摄动几何理论相结合的方法,建立了奇非线性行波方程研究的理论和方法,介绍奇非线性行波动力学行为的2个主要定理,完整地解决了波的光滑性与非光滑性、完整性和破缺性的判定问题.第四,介绍当伴随正则系统直线解上的奇点是结点时,如何用相轨道识别对应的波形,并研究一个非线性水波方程,获得该系统的各型光滑的孤立波和周期波在不同参数条件下的存在性和精确的参数表示. 展开更多
关键词 浅水方程模型 广义CAMASSA-HOLM方程 奇非线性行波方程 分枝 动力系统方法
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关于二阶伴随模型的理论研究 被引量:8
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作者 韩桂军 何柏荣 +1 位作者 马继瑞 李冬 《海洋学报》 CAS CSCD 北大核心 2000年第3期15-19,共5页
Hesse矩阵-目标函数关于控制变量的二阶偏导数形成的矩阵,在变分数据同化过程中以及敏感性分析等方面起着重要的作用;它可以通过建立数学模型的一阶和二阶伴随模型求得.以浅水方程模型为例,利用泛函的Gateaux微分和H... Hesse矩阵-目标函数关于控制变量的二阶偏导数形成的矩阵,在变分数据同化过程中以及敏感性分析等方面起着重要的作用;它可以通过建立数学模型的一阶和二阶伴随模型求得.以浅水方程模型为例,利用泛函的Gateaux微分和Hilbert空间上伴随算子的概念,导出了一阶和二阶伴随模型并由此得到Hesse矩阵.改进了 Zhi Wang等( 1992)建立的二阶伴随模型理论. 展开更多
关键词 HESSE矩阵 二阶伴随模型 浅水方程模型 海气模型
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无阀压电微流体泵工作特性与结构参数 被引量:3
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作者 鲁立君 吴健康 《机械工程学报》 EI CAS CSCD 北大核心 2008年第11期121-125,131,共6页
根据平面无阀压电微流体泵的结构特点,采用厚度平均的浅水模型和有限元法,得到微流体泵液体-振动片耦合方程。耦合方程的模态分析给出硅片一阶模态自然频率和振型,以及硅片振幅-频率关系。在模态分析之后,加入压电力考察振动片响应、微... 根据平面无阀压电微流体泵的结构特点,采用厚度平均的浅水模型和有限元法,得到微流体泵液体-振动片耦合方程。耦合方程的模态分析给出硅片一阶模态自然频率和振型,以及硅片振幅-频率关系。在模态分析之后,加入压电力考察振动片响应、微泵流动特征和微泵流量。同时研究微泵结构参数(微泵压电片半径、扩散管长度、最小宽度、扩散张角)对微流体泵液—固耦合系统的自然频率、振动片振幅和微泵流量的影响,得出对微流体泵优化设计有重要意义的结果。 展开更多
关键词 压电微流体泵 浅水方程模型 液体-振动片耦合方程
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PODEn4DVar对松弛系数和局地化半径的敏感性
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作者 宋海清 盛炎平 《北京信息科技大学学报(自然科学版)》 2012年第3期15-20,共6页
针对松弛系数和局地化半径的敏感性对PODEn4DVar同化方法性能的影响,以浅水波方程作为预报模型,测试了其对不同松弛系数α和局地化半径R的敏感性,获得了不同模型误差情形下该方法同化时产生的均方根误差变化情况,确定了不同模型误差时... 针对松弛系数和局地化半径的敏感性对PODEn4DVar同化方法性能的影响,以浅水波方程作为预报模型,测试了其对不同松弛系数α和局地化半径R的敏感性,获得了不同模型误差情形下该方法同化时产生的均方根误差变化情况,确定了不同模型误差时的最优松弛系数α和局地化半径R。实验结果表明,在模型有误差时,PODEn4DVar同化方法对参数地选取很敏感。选取最优参数值后,同化精度有了明显提高。 展开更多
关键词 本征正交分解的集合四维交分同化 数据同化 松弛系数 局地化半径 浅水方程模型
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N-Fold Darboux Transformation and Bidirectional Solitons for Whitham-Broer-Kaup Model in Shallow Water
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作者 王雷 高以天 +3 位作者 盖晓玲 孟得新 吕兴 于鑫 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第3期413-422,共10页
Under investigation in this paper is the Whitham-Broer-Kaup (WBK) system, which describes the dispersive long wave in shallow water. Through a variable transformation, the WBK system is casted into a general Broer-Kau... Under investigation in this paper is the Whitham-Broer-Kaup (WBK) system, which describes the dispersive long wave in shallow water. Through a variable transformation, the WBK system is casted into a general Broer-Kaup system whose Lax pair can be derived by the Ablowitz-Kaup-Newell-Segur technology. With symbolic computation, based on the aforementioned Lax pair, the N-fold Darboux transformation is constructed with a gauge transformation and the multi-soliton solutions are obtained. Finally, the elastic interactions of the two-soliton solutions (including the head-on and overtaking collisions) for the WBK system are graphically studied. Those multi-soliton collisions can beused to illustrate the bidirectional propagation of the waves in shallow water. 展开更多
关键词 Whitham Broer-Kaup system Bidirectional solitons Multi-soliton solutions N-fold Darboux transformation Lax pair
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Influence of Tidal Inlets on Tsunami Waves in the Atlantic (Charente Region, France)
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作者 Lubna Amal Amir Amandine Nicolle Jean-Christophe Maurin 《Journal of Shipping and Ocean Engineering》 2014年第9期262-270,共9页
The French Atlantic coast seismicity is minor to moderate. Nevertheless, in western (north and central) part of France, the active tectonics related to the south Armorican and the Bay of Biscay context results somet... The French Atlantic coast seismicity is minor to moderate. Nevertheless, in western (north and central) part of France, the active tectonics related to the south Armorican and the Bay of Biscay context results sometimes in shallow earthquakes with magnitude above five (e.g., the Oleron seismic crisis, magnitude (local) = 5.2, 1972). The Charente region is featured by semi-diurnal tides that reach about six meters in height during the high tide period. Inlets are the main features of the Atlantic margin geomorphology nearby the Charente. Minor tsunamis have been observed and reported in the past. Here, we present a tsunami modelling computed with the TELEMAC package that solves the non linear shallow water equations. This work helps to identify the role of the inlets that characterize the Charente's geomorphology on water wave's propagation. A tidal model is considered while the tsunami simulation is performed. The modelling results show that the Antioche, the Maumusson and the Pertuis inlets protect the Charente coast from destructive waves. 展开更多
关键词 Oleron Island French Atlantic INLET TSUNAMI earthquake modeling.
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Integrating 1D and 2D hydrodynamic,sediment transport model for dam-break flow using finite volume method 被引量:3
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作者 ZHANG MingLiang XU YuanYuan +1 位作者 HAO ZiNing QIAO Yang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第4期774-783,共10页
The purpose of this study is to set up a dynamically linked 1D and 2D hydrodynamic and sediment transport models for dam break flow.The 1D-2D coupling model solves the generalized shallow water equations,the non-equil... The purpose of this study is to set up a dynamically linked 1D and 2D hydrodynamic and sediment transport models for dam break flow.The 1D-2D coupling model solves the generalized shallow water equations,the non-equilibrium sediment transport and bed change equations in a coupled fashion using an explicit finite volume method.It considers interactions among transient flow,strong sediment transport and rapid bed change by including bed change and variable flow density in the flow continuity and momentum equations.An unstructured Quadtree rectangular grid with local refinement is used in the 2D model.The intercell flux is computed by the HLL approximate Riemann solver with shock captured capability for computing the dry-to-wet interface for all models.The effects of pressure and gravity are included in source term in this coupling model which can simplify the computation and eliminate numerical imbalance between source and flux terms.The developed model has been tested against experimental and real-life case of dam-break flow over fix bed and movable bed.The results are compared with analytical solution and measured data with good agreement.The simulation results demonstrate that the coupling model is capable of calculating the flow,erosion and deposition for dam break flows in complicated natural domains. 展开更多
关键词 1D/2D coupling model finite volume method HLL approximate Riemann solver non-equilibrium sediment transport
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On the Lie Algebras, Generalized Symmetries and Darboux Transformations of the Fifth-Order Evolution Equations in Shallow Water 被引量:2
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作者 Shoufu TIAN Yufeng ZHANG +1 位作者 Binlu FENG Hongqing ZHANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第4期543-560,共18页
By considering the one-dimensional model for describing long, small amplitude waves in shallow water, a generalized fifth-order evolution equation named the Olver water wave (OWW) equation is investigated by virtue ... By considering the one-dimensional model for describing long, small amplitude waves in shallow water, a generalized fifth-order evolution equation named the Olver water wave (OWW) equation is investigated by virtue of some new pseudo-potential systems. By introducing the corresponding pseudo-potential systems, the authors systematically construct some generalized symmetries that consider some new smooth functions {Xiβ}β=1,2…,N^i=1,2…,n depending on a finite number of partial derivatives of the nonlocal variables vβ and a restriction i,α,β∑( ξi/ vβ)^2+( ηα/ vβ)^2≠0,ie.,i,α,β∑( ξi/ vβ)^2≠0. Furthermore, i,a,B i,a,~ the authors investigate some structures associated with the Olver water wave (AOWW) equations including Lie algebra and Darboux transformation. The results are also extended to AOWW equations such as Lax, Sawada-Kotera, Kaup-Kupershmidt, It6 and Caudrey-Dodd-Cibbon-Sawada-Kotera equations, et al. Finally, the symmetries are ap- plied to investigate the initial value problems and Darboux transformations. 展开更多
关键词 Generalized symmetries Darboux transformations Analytical solutions
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