Development of a two-phase flow solver with drift-flux model based on OpenFOAM: Validation against single/two-phase and boiling flow

Based on the open-source finite volume method platform OpenFOAM, this paper implements a two-phase flow solver for drift partial non-equilibrium models with realistic closure relations. The solver inherits the numerical method from the OpenFOAM framework, adopts the large-time step transient PIMPLE algorithm, and follows its discrete and matrix-solving criteria, focusing on developing a two-phase flow model and constitutive models. The constitutive model is utilized as a library by the drift flux solver, covering the pre-CHF flow patterns in vertical channels. The drift velocity model is based on Ishii and his collaborators’ work. The remaining models, such as wall friction, wall heat transfer, interfacial heat and mass transfer, are taken from TRACE Theory Manual. To fulfill the condition of conjugate heat transfer between fluid and solid, a virtual solid heat transfer function is developed under the premise of a single-domain solver. Extensive and successful validation has been conducted involving single-phase, two-phase, and boiling flow heat transfer phenomena by comparing with experimental data or typical system codes, and the two-phase flow solver's success has been demonstrated in several aspects. This will support future multi-scale and multi-physics coupling work within the OpenFOAM framework.