Numerical Investigation on NOx Emission of a Hydrogen-Fuelled Dual-Cylinder Free-Piston Engine

The free-piston engine is a type of none-crank that could be operated under variable compression ratio, and this provides it flexible fuel applicability low emission potential. In work, several 1-D models, including conventional gasoline engines, engines hydrogen have been established. Both performance speeds between 5–11 Hz with different equivalent ratios simulated compared. Results indicated the has remarkable potential for NOx reduction, largest reduction 57.37% at 6 compared engine. However, figure from slightly higher than engine, difference increases increase speed. addition, factors their relationships related to combustion in investigated, results show ratio φ=0.88 vital point affects production, ignition advance timing also affect duration, highest in-cylinder temperature production large extent.