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

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.