返回
Implicit and semi-implicit second-order time stepping methods for the Richards equation
DOI:10.1016/j.advwatres.2020.103841.png)
摘要
En 中文
This study concerns numerical methods for efficiently solving the Richards equation where different weak formulations and computational techniques are analyzed. The spatial discretizations are based on standard or mixed finite element methods. Different implicit and semi-implicit temporal discretization techniques of second-order accuracy are studied. To obtain a linear system for the semi-implicit schemes, we propose second-order techniques using extrapolation formulas and/or semi-implicit Taylor approximations for the temporal discretization of nonlinear terms. A numerical convergence study and a series of numerical tests are performed to analyze efficiency and robustness of the different schemes. The developed scheme, based on the proposed temporal extrapolation techniques and the mixed formulation involving the saturation and pressure head and using the standard linear Lagrange element, performs better than other schemes based on the saturation and the flux and using the Raviart-Thomas elements. The proposed semi-implicit scheme is a good alternative when implicit schemes meet convergence issues.
Keyword:
Richards equation
Linearization schemes
Numerical convergence analysis
Second-order time-accuracy
Galerkin finite elements
Mixed finite elements
AI总结
对已上传原文的论文进行重点信息的提取,主要内容包括:简要概述、研究摘要、背景介绍、关键亮点、图文解析、展望与总结。
期刊
IF:
4.2
论文数:
4.6K
被引数:
1.5W
机构
引用论文
Polarized reflectance spectra of the one-dimensional superconductor Tl2Mo6Se6 - a comparison with the anisotropic superconductor (SN)x
Physica B+C
IF0

