An unstructured two-fluid method based on the coupled phasic exchange algorithm

An implicit multi-phase CFD formulation is presented. The differential model employed is the ensemble averaged full-two-fluid system, wherein continuity, momentum, energy and turbulence quantity conservation equations are solved for an arbitrary number of constituents. Models for non-equilibrium interfacial transfer are incorporated. Fully unstructured (i.e., four standard element types), second order discretization is employed. Elements of the Coupled Phasic Exchange (CPE) algorithm are employed, which accommodate the significant influence of inter-field transfer on discretization, operator splitting and linear solution elements of the scheme. In this paper, details of the CFD formulation and physical modeling are first summarized, with emphasis placed on multi-phase, unstructured and parallel processing elements. Several examples are provided which illustrate the ability of the scheme to model a variety of complex single and multi-component systems. These include gas-particle flow through a branching pipe junction with an internal obstruction, an axisymmetric bubble column flow and rotor-stator simulation of an axial pump stage.