A numerical model for trickle bed reactors

Trickle bed reactors are governed by equations of Row in porous media such as Darcy's law and the conservation of mass. Our numerical method for solvi ng these equations is based on a total-velocity splitting, sequential formu lation which leads to an implicit pressure equation and a semi-implicit mas s conservation equation. We use high-resolution finite-difference methods t o discretize these equations. Our solution scheme extends previous work in modeling porous media Rows in two ways. First, we incorporate physical effe cts due to capillary pressure, a nonlinear inlet boundary condition, spatia l porosity variations, and inertial effects on phase mobilities. In particu lar, capillary forces introduce a parabolic component into the recast evolu tion equation, and the inertial effects give rise to hyperbolic nonconvexit y. Second, we introduce a modification of the slope-limiting algorithm to p revent our numerical method from producing spurious shocks. We present a nu merical algorithm for accommodating these difficulties, show the algorithm is second-order accurate, and demonstrate its performance on a number of si mplified problems relevant to trickle bed reactor modeling. (C) 2000 Academ ic Press.