The MAST-edge centred lumped scheme for the flow simulation in variably saturated heterogeneous porous media

JOURNAL OF COMPUTATIONAL PHYSICS

卷:231

Article

Arico, Costanza¹  Sinagra, Marco¹  Tucciarelli, Tullio¹ 

[1] Univ Palermo, Dipartimento Ingn Civile Ambientale & Aerosp, I-90128 Palermo, Italy

关键词: Variably saturated porous medium;    Numerical model;    Finite element;    Lumped scheme;    Mass conservation;    Unstructured mesh;    Analytical solution;   

DOI  :  10.1016/j.jcp.2011.10.012

来源: Elsevier

【 摘 要 】

A novel methodology is proposed for the solution of the flow equation in a variably saturated heterogeneous porous medium. The computational domain is descretized using triangular meshes and the governing PDEs are discretized using a lumped in the edge centres numerical technique. The dependent unknown variable of the problem is the piezometric head. A fractional time step methodology is applied for the solution of the original system, solving consecutively a prediction and a correction problem. A scalar potential of the flow field exists and in the prediction step a MArching in Space and Time (MAST) formulation is applied for the sequential solution of the Ordinary Differential Equation of the cells, ordered according to their potential value computed at the beginning of the time step. In the correction step, the solution of a large linear system with order equal to the number of edges is required. A semi-analytical procedure is also proposed for the solution of the prediction step. The computational performance, the order of convergence and the mass balance error have been estimated in several tests and compared with the results of other literature models. (C) 2011 Elsevier Inc. All rights reserved.

【 授权许可】

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