Modeling of hydrodynamic dispersion and two-phase flow in the complex variable boundary element method

This study aims at extending the applicability of the complex variable boundary element method (CVBEM) to convective-dispersive flow and simultaneous two-phase flow problems. In order to utilize the analytical solutions obtained for one-dimensional (1D) problems, two-dimensional (2D) flow is decomposed into flow along multiple 1D streamlines. Varying velocity along the streamlines can be taken into account with the aid of a series of coordinate transformations tau and omega, which are accurately evaluated by the CVBEM. The complete 2D solution is recovered by composing the individual 1D solutions. For convective-dispersive flow, tracer concentration profiles and effluent concentration curves are directly constructed from the Gelhar-Collins solution. For two-phase flow, displacing fluid profiles and recovery efficiency curves are directly constructed from the self-similar solution. The numerical results for example problems confirm that the developed model enables flow computations devoid of discretization effects. (C) 2003 Elsevier B.V. All rights reserved.