Formation and Evolution of Thermal and Fuel Nitrogen Oxides in the Turbulent Combustion Field of Ammonia Internal Combustion Engines

• DOI: 10.4271/2023-01-0192
• Publication Date: 2023-04-07T20:12:47Z
• Authors: Ruomiao Yang; Yuchao Yan; Zhentao Liu; Jinlong Liu

<div class="section abstract"><div class="htmlview paragraph">Ammonia is a zero-carbon candidate fuel for the decarbonization of internal combustion (IC) engines. A concern when using ammonia in IC engines increased emissions nitrogen oxides (NO<sub>X</sub>), due to additional molecule. Compared conventional petroleum such as gasoline and diesel, adds NO<sub>X</sub> formation mechanism addition original thermal generation pathway, which further complicates emission characteristics Decoupling helps increase understanding evolutionary occurring inside engines, but available literature lacks studies this respect. The purpose study fill research gap propose methodology decoupling NO<sub>X</sub>. In brief, an artificial elemental applied Zeldovich diatomic air, allows from be separated formed air. three dimensional (3D) computational fluid dynamics (CFD) model demonstrates effectiveness approach investigates spatial temporal distribution turbulent field in-cylinder activity analysis suggests that separation slightly alters nitrogen-based chemistry, unavoidable. However, still reasonable characterization evolution simulations show during oxidation because intermediate species, while has high concentration burned zone it related temperature residence time at temperature, both are expected support successful atmospheric nitrogen. addition, nitrous oxide (N<sub>2</sub>O) come mainly distributed along liner walls by partial released crevices late process. Moreover, concentrations fuel-based monoxide vary with chemical equilibrium changes piston motion, their always comparable. As result, strategies needs consider reduction mechanisms, where main difficulty N<sub>2</sub>O reduction. Catalytic mode may viable strategy improve efficiency trapped crevice reduce cylinder.</div></div>