共查询到19条相似文献,搜索用时 125 毫秒
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主要讨论Klein-Gordon-Schrdinger方程的Fourier拟谱辛格式,包括中点公式和Strmer/Verlet格式.首先构造一个哈密尔顿方程,针对此哈密尔顿方程,在空间方向用Fourier拟谱离散得到一个有限维的哈密尔顿系统,对此有限维系统在时间方向用Strmer/Verlet方法离散得到KGS方程的完全显式的辛格式.中点格式虽然是隐式的但效率也很高,且具有质量守恒律.数值实验表明,辛格式能够在长时间内很好地模拟各类孤立波. 相似文献
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通过正则变换,构造出广义非线性Schr(o)dinger方程的多辛方程组.对此多辛方程组,导出了一个新的模方守恒多辛格式.数值实验结果表明,多辛格式具有长时间的数值行为,且在保持模方守恒律方面优于蛙跳格式和辛欧拉中点格式. 相似文献
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广义Zakharov-Kuznetsov方程作为一类重要的非线性方程有着许多广泛的应用前景,基于Hamilton空间体系的多辛理论研究了广义Zakharov-Kuznetsov方程的数值解法,讨论了利用Preissmann方法构造离散多辛格式的途径,并构造了一种典型的半隐式的多辛格式,该格式满足多辛守恒律、局部能量守恒律.数值算例结果表明该多辛离散格式具有较好的长时间数值稳定性. 相似文献
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耦合非线性Schr(o)dinger系统的多辛差分格式 总被引:2,自引:2,他引:0
近年来,Bridges等人在Hamiltonian力学意义下,直接把有限维Hamihonian系统推广到无穷维,通过引入新的函数坐标,使得偏微分方程在时间和空间的各个方向上都有各自不同的有限维辛结构,这样原偏微分方程就由各个有限维辛结构以及右端的梯度函数决定,称这样的方程为多辛Hamihonian系统.多辛Hamiltonian系统满足多辛守恒定律,满足多辛Hamihonian系统的多辛守恒律的离散算法称为多辛算法.以耦合非线性Schroedinger方程为例,研究无穷维Hamiltonian系统的多辛算法,验证了两孤立子碰撞后会发生相互通过、反射及融合现象. 相似文献
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王俊杰 《原子与分子物理学报》2013,30(6)
广义Zakharov-Kuznetsov 方程作为一类重要的非线性方程有着许广泛的应
用前景,基于Hamilton 空间体系的多辛理论研究了广义Zakharov-Kuznetsov方程的数值
解法,讨论了利用Preissmann 方法构造离散多辛格式的途径, 并构造了一种典型的半隐
式的多辛格式, 该格式满足多辛守恒律、局部能量守恒律. 数值算例结果表明该多辛离
散格式具有较好的长时间数值稳定性. 相似文献
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近年来,Bridges等人在Hamiltonian力学意义下,直接把有限维Hamiltonian系统推广到无穷维,通过引入新的函数坐标,使得偏微分方程在时间和空间的各个方向上都有各自不同的有限维辛结构,这样原偏微分方程就由各个有限维辛结构以及右端的梯度函数决定,称这样的方程为多辛Hamiltonian系统.多辛Hamiltonian系统满足多辛守恒定律,满足多辛Hamiltonian系统的多辛守恒律的离散算法称为多辛算法.以耦合非线性Schr dinger方程为例,研究无穷维Hamiltonian系统的多辛算法,验证了两孤立子碰撞后会发生相互通过、反射及融合现象. 相似文献
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对耦合Schrdinger方程组提出一个非耦合的线性化差分格式并对其进行分析.证明格式保持原方程组的守恒律,在先验估计的基础上证明格式依L2模的绝对稳定性和无条件二阶收敛性.对孤波碰撞的各种现象进行模拟. 相似文献
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《计算物理》2006,23(6):757-766
第1期计算中子增殖率的时间强迫碰撞方法……………………………王瑞宏邓力许海燕裴鹿成(1)Navier-Stokes方程的线性化微分求积法(英)……………………………………………李晨吴雄华(18)统一坐标系下多介质流体力学计算的一种方法…………………………………………………贾鹏彦(19)SRLW方程的多辛Fourier拟谱格式及其守恒律…………………孔令华曾文平刘儒勋孔令健(25)一类正交增强的阶谱六面体矢量单元构造……………………………………………李江海孙秦(32)SALE速度重映算法的改进……………………………………………………熊俊周海… 相似文献
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A High-Order Conservative Numerical Method for Gross-Pitaevskii Equation with Time-Varying Coefficients in Modeling BEC 下载免费PDF全文
《中国物理快报》2017,(6)
We propose a high-order conservative method for the nonlinear Schrodinger/Gross-Pitaevskii equation with time-varying coefficients in modeling Bose-Einstein condensation(BEC). This scheme combined with the sixth-order compact finite difference method and the fourth-order average vector field method, finely describes the condensate wave function and physical characteristics in some small potential wells. Numerical experiments are presented to demonstrate that our numerical scheme is efficient by the comparison with the Fourier pseudo-spectral method.Moreover, it preserves several conservation laws well and even exactly under some specific conditions. 相似文献
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We explore the multisymplectic Fourier pseudospectral discretizations for the (3+1)-dimensional Klein-Gordon equation in this paper. The corresponding multisymplectic conservation laws are derived. Two kinds of explicit
symplectic integrators in time are also presented. 相似文献
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In the paper, we describe a novel kind of multisymplectic method for three-dimensional (3-D) Maxwell’s equations. Splitting the 3-D Maxwell’s equations into three local one-dimensional (LOD) equations, then applying a pair of symplectic Runge–Kutta methods to discretize each resulting LOD equation, it leads to splitting multisymplectic integrators. We say this kind of schemes to be LOD multisymplectic scheme (LOD-MS). The discrete conservation laws, convergence, dispersive relation, dissipation and stability are investigated for the schemes. Theoretical analysis shows that the schemes are unconditionally stable, non-dissipative, and of first order accuracy in time and second order accuracy in space. As a reduction, we also consider the application of LOD-MS to 2-D Maxwell’s equations. Numerical experiments match the theoretical results well. They illustrate that LOD-MS is not only efficient and simple in coding, but also has almost all the nature of multisymplectic integrators. 相似文献
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We derive a new multisymplectic integrator for the Kawahara-type equation which is a fully explicit scheme and thus needs less computation cost. Multisympecticity of such scheme guarantees the long-time numerical behaviors. Nu- merical experiments are presented to verify the accuracy of this scheme as well as the excellent performance on invariant preservation for three kinds of Kawahara-type equations. 相似文献
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We investigate the multisymplectic Euler box scheme for the Korteweg-de Vries (KdV) equation. A new completely explicit six-point scheme is derived. Numerical experiments of the new scheme with comparisons to the Zabusky-Kruskal scheme, the multisymplectic 12-point scheme, the narrow box scheme and the spectral method are made to show nice numerical stability and ability to preserve the integral invariant for long-time integration. 相似文献
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The multisymplectic geometry for the Zakharov–Kuznetsov equation is presented in this Letter. The multisymplectic form and the local energy and momentum conservation laws are derived directly from the variational principle. Based on the multisymplectic Hamiltonian formulation, we derive a 36-point multisymplectic integrator. 相似文献
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A pseudo-spectral algorithm is presented for the solution of the rotating Green–Naghdi shallow water equations in two spatial dimensions. The equations are first written in vorticity–divergence form, in order to exploit the fact that time-derivatives then appear implicitly in the divergence equation only. A nonlinear equation must then be solved at each time-step in order to determine the divergence tendency. The nonlinear equation is solved by means of a simultaneous iteration in spectral space to determine each Fourier component. The key to the rapid convergence of the iteration is the use of a good initial guess for the divergence tendency, which is obtained from polynomial extrapolation of the solution obtained at previous time-levels. The algorithm is therefore best suited to be used with a standard multi-step time-stepping scheme (e.g. leap-frog). 相似文献