自然科学版
陕西师范大学学报(自然科学版)
数学与计算机科学
插值法解时间分数阶扩散方程
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闵宝峰,张学莹*
(河海大学 理学院, 江苏 南京 211100)
张学莹,男,副教授,研究方向为偏微分方程数值解法和计算流体力学。E-mail: zhangxy@hhu.edu.cn
摘要:
针对一类时间分数阶扩散方程提出了一种新的隐式差分格式,空间导数直接采用中心差分格式离散,为了近似Caputo型时间分数阶导数,在小区间\[tn-1,tn\](2≤n≤N)上使用三点u(x,tn-2)、u(x,tn-1)、u(x,tn)二次插值近似u(x,t)的值,在小区间\[t0,t1\]上使用线性插值近似u(x,t)的值,并利用能量范数证明该格式的无条件稳定性和收敛性,最后通过数值实验验证该格式的有效性。
关键词:
时间分数阶扩散方程;隐式差分格式;稳定性;收敛性
收稿日期:
2017-03-08
中图分类号:
O242.1; O302
文献标识码:
A
文章编号:
1672-4291(2018)03-0055-05
基金项目:
教育部留学回国人员科研启动基金(20145003412);江苏省自然科学基金(BK20160853)
Doi:
Interpolation method for the time fractional diffusion equation
MIN Baofeng, ZHANG Xueying*
(College of Science, Hohai University, Nanjing 211100, Jiangsu, China)
Abstract:
A new implicit difference approximation to solve a time fractional derivative equation is proposed.The spatial derivative is directly discretized by central difference scheme. To approximate the Caputo fractional derivative, it is established by means of the quadratic interpolation approximation. Using three points u(x,tn-2),u(x,tn-1),u(x,tn) for the integrand u(x,t) on each small interval \[tn-1,tn\](2≤n≤N), while the linear interpolation approximation is applied on the first small interval \[t0,t1\].Using the energy norm, the unconditional stability and convergence of the scheme are proved.Finally, a numerical experiment shows that the scheme is efficient.
KeyWords:
time fractional diffusion equation; implicit difference scheme; stability; convergence