Numerical Investigation of Engine Performance and Emission Characteristics of an Ammonia/Hydrogen/n-Heptane Engine Under RCCI Operating Conditions

Abstract This paper examines the potential of using ammonia (NH $$_3$$ 3 ) as a primary fuel in heavy-duty engines for decarbonization, with some challenges yet to be addressed. It presents numerical study Reactivity Controlled Compression Ignition engine, where pilot diesel is used ignite premixed ammonia/air mixture. The model and combustion mechanism are validated against engine experimental results methanol iso-octane fuels ignition delay times ammonia/n-heptane mixtures measured rapid compression machine. findings show that can effectively operate up 50% total energy supplied by ammonia, albeit slightly elevated NO emissions compared diesel-fueled engine. Increasing further leads lower efficiency. Hydrogen utilized enhance combustion; however, increase further. Ammonia leakage primarily originates from regions near cold wall, center cylinder, crevice. N $$_2$$ 2 O mainly forms at flame front. Emission therefore due front quenching wall.