Calculation of Inhomogeneous-Charge Combustion in a Swirl-Assisted Lean-Burn Engine
A multidimensional computational method is extended to include the methodology for modelling of partially-mixed inhomogeneous charge combustion and is applied to investigation of combustion and simultaneous mixing process of an inhomogeneous mixture in a lean-burn spark-ignition engine. The in-cylinder flow and charge mixture distribution pertain to a helical intake port with manifold fuel injection, and were obtained through complete simulation of the induction and compression processes. The engine compression ratio is 12:1 and the study pertains to the operating condition of 2500 rpm. The results show that the flow and charge distribution at the time of ignition is predominantly characterised by the evolution of the induction flow. The effect of heat release on enhancement of charge mixing is marginal and the pre-ignition charge distribution is preserved throughout the combustion.