Large-eddy simulation of spray assisted dual-fuel ignition under reactivity-controlled dynamic conditions

Here, a large-eddy simulation and finite-rate chemistry solver (see Kahila et al. Combustion Flame, 2019) is utilized to investigate diesel spray assisted ignition of lean methane-air mixture. A compression heating model emulate the ambient temperature pressure increase in (CI) system. The key parameter start injection (SOI) relative virtual top dead center (TDC), where peak adiabatic pressure/temperature would be achieved. Altogether, five different cases are investigated by advancing SOI further away from TDC with constant duration. main findings paper as follows: 1) Advancing advances timing respect 0.91 7.08 CAD. However, beyond critical point, time starts retarding towards 4.46 CAD due excessively diluted spray. 2) increases contribution leaner mixtures heat release rate (HRR). Consequently, low-temperature combustion HRR mode becomes more pronounced (from 33.9% 76.7%) while total reduced factor 4. 3) Ignition observed for all SOI’s. numerical indicate that decreases kernel size, resulting weaker ignition. 4) An index analysis frozen flow assumption indicates SOI’s close appears mixing controlled, advanced it reactivity dominated fuel stratification.