检索结果-南通市图书馆

Design of a new dynamical core for global atmospheric models based on some efficient numerical methods

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2004年第z1期47卷 4-21页

作者： WANG Bin, WAN Hui, Jl Zhongzhen, ZHANG Xin, YU Rucong, YU Yongqiang & LIU HongtaoState Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese academy of Sciences, beijing 10002.,{2. department of computational mathematics, academy of mathematics and system Sciences, peking university, beijing 100871,{2. Chinese Acad Sci Inst Atmospher Phys State Key Lab Numer Modeling Atmospher Sci & Geop Beijing 100029 Peoples R China peking Univ Acad Math & Syst Sci Dept Computat Math Beijing 100871 Peoples R China

A careful study on the integral properties of the primitive hydrostatic balance equations for baroclinic atmosphere is carried out, and a new scheme todesign the global adiabatic model of atmospheric dynamics ispresented. This scheme includes a method of weighted equal-areamesh and a fully discrete finite difference method with quadraticand linear conservations for solving the primitive equationsystem. Using this scheme, we established a new dynamical corewith adjustable high resolution acceptable to the availablecomputer capability, which can be very stable without anyfiltering and smoothing. Especially, some important integralproperties are kept unchanged, such as the anti-symmetries of thehorizontal advection operators and the vertical convectionoperator, the mass conservation, the effective energy conservationunder the standard stratification approximation, and so on. Somenumerical tests on the new dynamical core, respectively regardingits global conservations and its integrated performances inclimatic modeling, incorporated with the physical packagesfrom the Community Atmospheric Model Version 2.(CAM2. of NationalCenter for Atmospheric Research (NCAR), are included.

关键词： dynamical core, equal-area mesh, anti-symmetry, effective energy conservation.

CONVERGENCE OF VORTEX METHODS FOR 3-D EULER EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of computational mathematics 2000年第3期18卷 239-250页

作者： Jia-fu Lin (Institute of system Science, academy of {2. and system Sciences, Chinese academy of Sciences, beijing, 100080, china School of Mathematical Sciences, peking university, beijing 100871, china) 中科院系统科学所北京 100080

Presents a study on the convergence of vortex methods for the three-dimensional Euler equations in bounded domains. Related studies on the convergence of vortex methods; Formulation of vortex methods; Convergence for ... 详细信息

关键词： Euler equations vortex methods convergence initial-boundary value problem

Recovery of the scale-ε2.pattern by lattice BGK model

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 2001年第1期6卷 40-44页

作者： Guangwu YAN and Li YUAN (Institute of computational mathematics, {2. of mathematics and system Sciences, Chinese {2. of Sciences, beijing 100080, china department of mathematics, Jinn university, Chongchun 13002., china) Inst. of computational mathematics Acad. of Math. and System Sciences Chinese Academy of Sciences Beijing 100080 China department of mathematics Jilin University Changchun 130023 China

A lattice BGK method for nonlinear chemical reactions is described. Since the equation does not possess the convect terms, we can easily get the equilibrium distribution functions of the lattice BGK models. Using this... 详细信息

关键词： lattice BGK method Turing pattern mosaic structure

CONVERGENCE OF CHORIN-MARSDEN FOR MULA FOR THENAVIER-STOKES EQUATIONS ON CONVEX DOMAINS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of computational mathematics 1999年第1期17卷 73-88页

作者： Lung-an Ying(Research institute for Mathematical Sciences, Kyoto university, Japan department of {2., peking university, beijing 100871, china) peking Univ Dept Math Beijing 100871 Peoples R China Kyoto Univ Math Sci Res Inst Kyoto Japan

We prove the convergence of the Chorin-Marsden product formula for solving the initial-boundary value problems of the Navier-Stokes equations on convex domains. As a particular case we consider the case of the half pl... 详细信息

关键词： Navier Stokes equation vortex method fractional step method convergence

Lattice Boltzmann solver of Rossler equation

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 2000年第2期5卷 64-68页

作者： Guangwu YAN and Li RUAN (LSEC Institute of computational mathematics, {2. of mathematics and system Sciences, Chinese {2. of Sciences, beijing 100080, china department of mathematics, Jilin university, Changchun 13002., china) LSEC Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China department of mathematics Jilin University Changchun 130023 China

We proposed a lattice Boltzmann model for the Rossler equation. Using a method of multiscales in the lattice Boltzmann model, we get the ditheion reaction as a special case. If the diffusion effect disappeared, we can obtain the lattice Boltzmann solution of the Rossler equation on the mesescopic scale. The numericale results show the method can be used to simulate Rossler equation.

关键词： lattice Boltzmann method multiscale technique Rossler equation

ON THE CENTRAL RELAXING SCHEME Ⅱ: systemS OF HYPERBOLIC CONSERVATION LAWS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of computational mathematics 2001年第6期19卷 571-582页

作者： Hua-zhong Tang (School of Mathematical Sciences, peking university, beijing 100871,{2.) (LSEC,ICMSEC academy of mathematics and systems Sciences, Chinese academy of Sciences, beijing 100080,{2.) School of Mathematical Sciences Peking University Beijing 100871 China

This paper continues to study the central relaxing schemes for system of hyperbolic conservation laws, based on the local relaxation approximation. Two classes of relaxing systems with stiff source term are introduced to approximate system of conservation laws in curvilinear coordinates. Based on them, the semi-implicit relaxing schemes are con- structed as in [6, 12. without using any linear or nonlinear Riemann solvers. Numerical experiments for one-dimensional and two-dimensional problems are presented to demon- strate the performance and resolution of the current schemes.

关键词： Hyperbolic conservation laws The relaxing system The central relaxing schemes The Euler equations.

Lattice Boltzmann model for the perfect gas flows with near-vacuum region

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 2000年第2期5卷 58-63页

作者： Guangwu YAN and Li YUAN (LSEC, Institute of computational mathematics, {2. of mathematics and system Sciences,Chinese {2. of Sciences, beijing 100080, china department of Mathermatics, Jilin university, Changchun 13002., china) LSEC Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China department of mathematics Jilin University Changchun 130023 China

It is known that the standard lattice Boltzmann method has near-vacuum limit,i. e., when the density is near zero, this method is invalid. In this letter, we propose a shople lattice Boltzmann model for one-dimensional fiows. It possesses the ability of simulating near vacuum area by setting a limitation of the relaxation factor. Thus, the model overcomes the disadvantage of non-physical pressure and the density. The numerical examples show these results are satisfactory.

关键词： lattice Boltzmann method perfect gas near-vacuum region Roe’s tests

L~∞ CONVERGENCE OF QUASI-CONFORMING FINITE ELEMENTS FOR THE BIHARMONIC EQUATION

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of computational mathematics 1995年第2期13卷 108-122页

作者： Wang Ming (department of mathematics,{2., beijing, china) 北京大学数学系北京

In this paper we consider the L∞ convergence for quasi-conforming finite ele-ments solving the boundary value probzlems of the biharmonic equation and give the nearly optimal order L∞ estimates.

关键词： Biharmonic equations Vertices Rectangles Interpolation Technology Polynomials Estimation methods Weighting functions Greens function Mathematical inequalities

On the coupled NBEM and FEM for a class of nonlinear exterior Dirichlet problem in R^(2.)

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2004年第z1期47卷 181-189页

作者： WU Zhengpeng, KANG Tong & YU DehaoInstitute of computational mathematics and Scientific/Engineering Computing, {2. of mathematics and system Sciences, Chinese {2. of Sciences, beijing 100080, china department of Applied mathematics, beijing Broadcasting Institute, beijing 10002., china Combinatorial and computational mathematics Center, Pohang university of Science and Technology, Phoang 790-784, Republic of Korea Chinese Acad Sci Acad Math & Syst Sci Inst Computat Math & Sci Engn Comp Beijing 100080 Peoples R China beijing Broadcasting Inst Dept Appl Math Beijing 100024 Peoples R China Pohang Univ Sci & Technol Combinatorial & Computat Math Ctr Phoang 790784 South Korea

In this paper, based on the natural boundary reduction advanced by Feng and Yu, we couple the finite elementapproach with the natural boundary element method to study theweak solvability and Galerkin approximation of a class ofnonlinear exterior boundary value problems. The analysis is mainlybased on the variational formulation with *** provethe error estimate of the finite element solution and obtain theasymptotic rate of convergence. Finally, we also give anumerical example.

关键词： natural boundary integral method, finite element method, coupling method, error estimate.