Numerical Investigation Hydrogen Jet Ignition Process in a Constant Volume Vessel

Against the backdrop of the energy crisis and the “dual carbon” goals, developing efficient and clean internal combustion engine technologies is crucial. As an important technology of zero-carbon engines, hydrogen jet ignition systems offer a promising solution for igniting lean mixtures, overcoming challenges like unstable combustion with traditional spark plugs. This study investigates the flame propagation process of a hydrogen jet ignition system within a constant volume vessel, focusing on the underexplored area of jet flame development under varying injection pressures and working temperatures. A three-dimensional computational fluid dynamics (CFD) model of a passive pre-chamber ignition device connected to a constant volume vessel is established and validated. Simulations are conducted to analyze jet flame characteristics across different injection pressures, and subsequently at different working temperatures at the identified optimal pressure. Results indicate that higher injection pressure delays jet flame formation but prolongs its duration and increases peak temperature and heat release rate, with 2.5 MPa determined as optimal. Conversely, increasing the working temperature significantly accelerates jet flame formation and shortens its duration, while attenuating roll-up structures and enhancing the heat release rate, with 700 K identified as the most suitable temperature at 2.5 MPa injection pressure. This work provides fundamental insights into optimizing hydrogen jet ignition systems for stable lean combustion.