DEVELOPMENT AND VALIDATION OF A TWO-PHASE FLOW SOLVER WITH DRIFT-FLUX MODEL BASED ON OPENFOAM

The thermal-hydraulic system code is an important support of the design, safety and operation of nuclear reactor. With the rapid development of numerical methods and software engineering, the modernization of thermal-hydraulic system code development becomes more and more important. Based on the open source finite volume solution platform OpenFOAM, this paper develops a system-level two-phase flow solver for calculating reactor pipelines, aiming to realize the reactor thermal hydraulic system program through the idea of computational fluid dynamics. In this study, the drift partial non-equilibrium model is adopted to take into account the calculation accuracy and calculation speed. The governing equations of the two-phase flow model are converted into a form suitable for OpenFOAM programming specifications, and a series of constitutive model classes are established to close the governing equations. For the developed solver, other thermal-hydraulic system codes and experimental data are used to test and verify the solver's ability to simulate single-phase, subcooled boiling, and flow boiling conditions. The results show that the solver developed in this paper successfully realizes the system-level two-phase flow calculation in pipelines. This work is the first step towards the ultimate goal of expanding the capabilities of the developed solver to the calculation of closed loop systems in the reactor.