Impact of flash boiling multiple injections timing on the combustion and thermal efficiency of a gasoline direct injection engine under lean-burn

Lean burn mode of direct injection spark ignition engines (DISI) can improve the engine's thermal efficiency. However, it showed slow flame propagation and combustion instabilities which are strongly related to mixture distribution. Multiple injections control over in-cylinder charge distribution consequently on mode. Additionally, multiple reduce spray impingement enhance turbulence in compression stroke, particularly with late injection, but time is not enough for evaporation. Fuel under flash boiling conditions boosts fuel vaporization spray-airflow interaction injections. This study investigates effect lean gasoline/air an optical DISI engine. work uses Mie scattering, CFD, high-speed imaging, images postprocessing model investigate characteristics, interaction, propagation, CH* digital intensity. The results reveal that has significantly mitigated liquid intensity indicates elevated rate reduced better tumble flow compared subcooled single injection. optimal engine performance were achieved when second highest ratio point timely synchronized, example, 260°bTDC at 800 rpm 280°bTDC 1500 rpm. Thus, effectively efficiency by 54.65% 11%, respectivly. heat release could lean-burn operation