Host: The Japan Society of Mechanical Engineers
Name : The Ninth International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA 2017)
Date : July 25, 2017 - July 28, 2017
A modified 2-D Flamelet model was further developed and validated under various engine operating conditions. It was extended from 2-D flamelet model (C. Hasse, 2004) by simplifying the calculation procedures in extremely rich and lean region which can reduce the CPU time from the original one. Additionally, the collapsing method (C. Felsch, 2009) was introduced, and the model was extended to quadruple injection by applying the collapsing method twice. The simulation cases cover multiple injection strategies including triple and quadruple injection with different EGR rate, and the simulations were carried out by a commercial light-duty diesel engine with n-heptane skeletal chemical mechanism of which considers 29 species and 52 reactions. Simulation results show that the model can capture auto-ignition, mass and heat transfer of each fuel stream, in-cylinder pressure, heat release rate and NOx emissions under multiple fuel stream conditions. Particularly, the model could analyze the combustion process by the interaction of multiple fuel stream, which gives important information on the emissions reduction by multiple injection strategies. Based on the model, the effect on the advanced injection strategies to the reduction of emissions was quantitatively investigated. The quantitatively investigated results could be specified by analyzing how the change of injection timing, duration and the number of injection event can affect the solution of governing equation and corresponding mixture fraction domain.
