An Infinite Element Approach of a Spherically Symmetric Flow Problem in a Semi-Infinite Region

摘要

A transient infinite element is developed for a spherical symmetric flow problem in a porous region of infinite extent, which can be encountered during deep geological disposal of chemical wastes in pressurized boreholes with enlarged cavities [1]. Two finite-infinite element coupling procedures are presented in terms of the coupled boundary PDEs instead of at the matrix level. Such coupling procedures can be easily implemented in the commercial software, e.g. COMSOL Multiphysics, by using the Dirichlet and Robin boundary conditions. The close correlation of numerical results and the analytical solution indicates that the proposed finite-infinite element coupling approach can give the correct artificial boundary condition in the finite element modeling for the unbounded domain problem.