Heat Transfer,Knock Modeling and Cyclic Variability in a “Downsized”Spark-Ignition Turbocharged Engine  

作　　者：Fabio Bozza Daniela Siano Michela Costa 

机构地区：[1]Universita di Napoli “Federico II”,DIME,Via Claudio 21,80125 Napoli,Italy [2]Istituto Motori-CNR,Viale Marconi 8,80125 Napoli,Italy

出　　处：《Advances in Applied Mathematics and Mechanics》2011年第3期310-326,共17页应用数学与力学进展（英文）

摘　　要：In the present paper a combined procedure for the quasi-dimensional modelling of heat transfer,combustion and knock phenomena in a “downsized”Spark Ignition two-cylinder turbocharged engine is presented.The procedure is extended to also include the effects consequent the Cyclic Variability.Heat transfer is modelled by means of a Finite Elements model.Combustion simulation is based on a fractal description of the flame front area.Cyclic Variability(CV)is characterized through the introduction of a random variation on a number of parameters controlling the rate of heat release(air/fuel ratio,initial flame kernel duration and radius,laminar flame speed,turbulence intensity).The intensity of the random variation is specified in order to realize a Coefficient Of Variation(COV)of the Indicated Mean Effective Pressure(IMEP)similar to the one measured during an experimental campaign.Moreover,the relative importance of the various concurring effects is established on the overall COV.A kinetic scheme is then solved within the unburned gas zone,characterized by different thermodynamic conditions occurring cycle-by-cycle.In this way,an optimal choice of the “knock-limited”spark advance is effected and compared with experimental data.Finally,the CV effects on the occurrence of individual knocking cycles are assessed and discussed.

关 键 词：Finite elements in heat transfer internal combustion engines modelling cyclic variability KNOCK 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]