Spray Dynamics Characterization of Directly Injected Hydrogen into High-Pressure Medium: A Numerical Study

The use of hydrogen as a fuel in internal combustion engines holds promise for reduced emissions and improved efficiency. However, the injection and spray characteristics of gaseous hydrogen in high-pressure environments require further study to enable the development of optimized hydrogen injectors. Numerical simulations can provide such deep insight, however, models developed for hydrogen spray in the literature are scarce, as well as they are commonly validated using experimental data of working fluids other than hydrogen. In this work, a two-dimensional computational fluid dynamics (CFD) model, incorporating a discrete phase model (DPM), was developed to quantify the spray characteristics, such as penetration distance and spray angle, of directly injected hydrogen into a chamber filled with pressurized argon gas. The performance of the model was evaluated by comparing the numerical results against experimental data of hydrogen spray. The results showed that the 2D CFD-DPM model was able to reasonably capture the penetration length of the hydrogen spray. However, the model failed to accurately represent the angular dispersion of the hydrogen spray within the pressurized argon medium. To address the limitations of the 2D approach, future work will focus on extending the model to a three-dimensional (3D) domain, as well as implementing other advanced multiphase models, such as Volume of Fluid (VOF). These improvements are expected to provide a deeper understanding of the complex hydrogen spray characteristics in high-pressure environments, which can aid in the design and optimization of hydrogen injectors for internal combustion engine applications.