计算物理 ›› 2013, Vol. 30 ›› Issue (4): 491-500.

• 论文 • 上一篇    下一篇

时间分数阶亚扩散方程的高阶差分方法

曾凡海, 李常品   

  1. 上海大学理学院数学系, 上海 200444
  • 收稿日期:2012-11-12 修回日期:2013-01-26 出版日期:2013-07-25 发布日期:2013-07-25
  • 通讯作者: 李常品(1968-),男,博士,教授.研究方向为分数阶微分方程数值计算、分数阶动力学,E-mail:lcp@shu.edu.cn
  • 作者简介:曾凡海(1982-),男,博士生.研究方向:分数阶微分方程数值计算,E-mail:fanhaiz@shu.edu.cn
  • 基金资助:
    上海市教委科研创新重点项目(12ZZ084)资助

High-order Finite Difference Methods for Time-fractional Subdiffusion Equation

ZENG Fanhai, LI Changpin   

  1. Department of Mathematics, College of Sciences, Shanghai University, Shanghai 200444, China
  • Received:2012-11-12 Revised:2013-01-26 Online:2013-07-25 Published:2013-07-25

摘要: 提出两差分格式求解时间分数阶亚扩散方程.两个格式都是绝对稳定的,收敛阶均为O(τq+h2),其中q(q=2-β或2)与方程解的光滑性有关,β(0 < β < 1)是分数阶导数的阶、τh分别是时间和空间方向步长.数值实验验证了理论结果的正确性,并与其他方法进行比较,显示了本文方法的有效性和精确性.

关键词: 亚扩散方程, 分数阶线性多步法, 高阶方法, 稳定性, 收敛性

Abstract: Two finite difference methods for time-fractional subdiffusion equation with Dirichlet boundary conditions are developed.The methods are unconditionally stable and convergent of order(τq+h2) in the sense of discrete L2 norm,where q(q=2-β or 2) is related to smoothness of analytical solution to subdiffusion equation,β(0 < β < 1) is order of the fractional derivative,τ and h are step sizes in time and space directions,respectively.Numerical examples are provided to verify theoretical analysis.Comparisons with other methods are made,which show better performances over many existing ones.

Key words: subdiffusion equation, fractional linear multistep method, high-order methods, stability, convergence

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