A real-fluid low-dissipative solver for flash boiling simulations of non-equilibrium mixtures

• Published in: International journal of heat and mass transfer 2024-06, Vol.225, p.125391, Article 125391
• Main Authors: Duronio, Francesco, Battistoni, Michele, Di Mascio, Andrea, De Vita, Angelo, Rahantamialisoa, Faniry Nadia Zazaravaka, Zembi, Jacopo
• Format: Article
• Language: English
• Subjects: Flash boiling; Flux-splitting scheme; HRM; Multi-phase flow; Near nozzle flow; Real fluid properties; Under-expanded jets
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2024.125391

An Eulerian fluid-dynamic code for simulating compressible, multi-phase flows with phase transition modeling was developed. The code features a low-dissipative flux-splitting discretization scheme, a real-fluid library to properly describe thermophysical properties, and a phase transition model for flows with thermal non-equilibrium. Large Eddy Simulations of the internal and near nozzle flow of a fuel injector were carried out to assess the capabilities of the developed approach. X-ray measurements of iso-octane injections were exploited for validation purposes. Propane injections were then deeply investigated to verify the ability of the mathematical model to represent under-expanded two-phase jets properly. The results provide essential insights on the fluid-dynamic behavior of such two-phase jets, which can also be extended to the injection of alternative fuels like methanol, hydrogen, propane, and in general high-volatility e-fuels. •Under-expanded multi-phase jets simulation.•Development of multi-phase, low-dissipative CFD solver with phase transition.•Model validated against iso-octane x-ray and propane Schlieren data.•Primary and secondary under-expanded jets and spray collapse properly predicted.•Smaller Mach disc in super-critical injection compared to sub-critical liquid injection.