On the consistency of mechanistic multidimensional modeling of gas/liquid two-phase flows

The purpose of this paper is to present an overview of selected aspects of the mathematical modeling of multiphase flows, including the formulation of governing equations, gas/liquid interfacial forces and bubble/bubble interactions. Links between the combined physical, mathematical and computational models are discussed, including the recent progress in, and the limitations of, computational multiphase fluid dynamics (CMFD). Major differences and similarities are analyzed between the interpenetrating-fluids multifield modeling concept and the model of dispersed two-phase flows. Conditions are formulated under which the multifield modeling framework is applicable to gas/liquid dispersed bubbly flows. Also, the interactions between the continuous and dispersed fields are discussed, including a new mechanistic modeling concept for the turbulence-induced interfacial forces between the continuous liquid and dispersed bubbles. Finally, a multigroup approach to the modeling of bubble coalescence and breakup is presented. (c) 2008 Elsevier B.V. All rights reserved.