Understanding the difference in combustion and flame propagation characteristics between ammonia and methane using an optical SI engine

• NH 3 and CH 4 combustion were comparatively studied in an optical SI engine. flame features a similar main duration to flame. slower initial development higher stretch sensitivity. Ammonia exhibits response turbulence comparison methane. As carbon-free hydrogen-carrier fuel with high content of hydrogen, ammonia (NH ) unfavorable properties such as low flammability large cyclic variations, requiring further investigation actual engines. In this work, for the first time, using single-cylinder spark ignition (SI) engine compression ratio, performance well propagation characteristics investigated. Synchronization measurement in-cylinder pressure high-speed photography was performed, compared between methane under same operating conditions. The results show that stability power capability are significantly lower than Further analysis combining phasing indicates burning time loss mainly comes from process rather which deficit performance. average probability maps location indicate front two fuels emerges obviously different characteristics. Quantitative solving shows sensitivity is macroscopically reflected variations. Furthermore, quantification solved observed much effects methane, driven by while temperature ammonia. current study shall provide insights into application internal