1D Modeling of a High-Performance Engine Fueled with H ₂ and Equipped with a Low NO _x After-Treatment Device

Hydrogen engines are currently considered as a viable solution to preserve the internal combustion engine (ICE) as a power unit for vehicle propulsion. In particular, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations, due to their reduced emission levels and high thermodynamic efficiency. Lean charge is suitable for the purpose of passenger car applications, where the demand of mid/low power output does not require an excessive amount of air to be delivered by the turbocharging unit, but can difficulty be tailored in the field of high performance engine, where the air mass delivered would require oversized turbocharging systems or more complex charging solutions. For this reason, the range of feeding conditions near the stochiometric value is explored in the field of high performance engines, leading to the consequent issue of abatement of pollutant emissions. In this work a 1D model is applied to the modeling of a V8 engine fueled with direct injection (DI) of hydrogen. The engine has been derived by a gasoline configuration and adapted to hydrogen in such a way to keep the same performance. The lambda condition has been chosen as a best compromise between performances and emissions, focusing onto a single cylinder configuration. The calibration of the engine has been performed onto this single cylinder configuration, tailoring the same power output and delivering the air mass flow imposing the desired boost pressure to match the desired engine torque. Then, the 1D schematic of a V8 engine has been built, based on the developed single cylinder and the air delivery system configured to satisfy the required air mass flow rate. Three different test cycles have been investigated (one WLTP and two RDEs) with different driving conditions. The after treatment system has been consequently sized to guarantee the abatement of NO_x and the pollutant emissions analyzed showing different scenarios that can be adopted for this kind of engines, guaranteeing the reduced level of pollutant emissions and keeping the desired performance and fun of drive.