Simulation of a two-phase loop thermosyphon using a new interface-resolved phase change model

• Published in: International journal of heat and mass transfer 2024-08, Vol.228, p.125607, Article 125607
• Main Authors: Caner, Julien, Videcoq, Etienne, Benselama, Adel M., Girault, Manuel
• Format: Article
• Language: English
• Subjects: Engineering Sciences; Fluids mechanics; Liquid-vapor phase change; Low mach compressible flow; Mechanics; Passive cooling system; Thermics; Two-phase loop thermosyphon; Volume-of-fluid
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2024.125607

The remarkable progress made in power electronics has been coupled with the miniaturization of systems, requiring high-performance cooling. A solution that has garnered significant interest involves the use of two-phase loops, in which heat transfer is associated with the phase change of the working-fluid. This paper aims at modeling two-phase flow with separated phases in a gravity-driven two-phase loop. The Volume-of-Fluid method is employed to capture the moving interface. Amid the variety of the phase change models available in the literature, we have chosen to employ a hybrid model: a subgrid-scale model to generate phase change at the wall in the absence of an interface, and a interface-resolved model for phase change at pre-existing liquid-vapor interfaces. These models have been implemented in the OpenFOAM computational code. The developed solver makes possible the simulation of compressible laminar two-phase flow with diabatic liquid-vapor phase change. Conjugate heat transfer between the wall and the fluid is also taken into account. Two-dimensional numerical simulations demonstrate that the developed solver is capable of reproducing flow regimes obtained from experiments, including the formation of Taylor bubbles and the propulsion of liquid from the evaporator to the condenser during geyser boiling. Furthermore, this study examines how the filling ratio affects flow regimes and performance. •Simulations of a Two-phase loop thermosyphon are performed with a 4-equation model.•A compressible Volume-of-Fluid method with isoAdvector advection formulation is used.•A hybrid Lee-Tanasawa phase change model is implemented in the OpenFOAM framework.•Thermal resistance of the loop and liquid oscillation frequency are computed.•The effect of filling ratio of methanol on the loop global performances is analyzed.