Use of ammonia as a fuel for SI engine

Duynslaegher, Catherine [UCL] Jeanmart, Hervé [UCL] Vandooren, Jacques [UCL]

This numerical study examines the combustion characteristics of premixed ammonia-air mixtures, with equivalence ratios around stoichiometry, at elevated pressure and temperature conditions which are encountered in SI engine operations. The laminar burning velocity, the final flame temperature and species concentrations were determined using the Konnov’s mechanism. A flat freely propagating flame was considered. Both equivalence and compression ratios have an important impact on the laminar burning velocity and on the adiabatic flame temperature. Furthermore, only the variation of the equivalence ratio has a major incidence on the nitrogen monoxide formation. The compression ratio and, therefore, the final temperature do not have a significant impact on NO yields for equivalence ratios above the stoichiometry.