Development of Four-Zone Segmented Transitional Model for Reciprocating Internal Combustion Engine Analysis Using Gasoline

Abstract

A four zone model based on the first law of thermodynamics has been developed for analysis of combustion in an internal combustion engine. The four zones included an unburned zone and two regions of burned zone, (namely burned gas1 and burned gas 2) and unburned burned zone described as a transitory zone which is a mixture of burned and unburned gases. Arbitrary constant for each of burn (CC2) and unburned (CC1) zone leakages in unburned burned zone was evaluated at optimally predetermined values of 0.005 and 0.00025 respectively, while mass fraction burned from burned gas1, x1 and burned gas 2, x2 were also evaluated at predetermined optimal values of 0.6 and 0.4 respectively. The model was used to analyse an SI engine operating with a gasoline fuel. The engine operating conditions were set at engine speed of 2000 rpm, -35bTDC ignition time and burn duration at 60°. The temperature distribution from the arbitrary constants (CC2, CC1, x1 and x2) for the newly developed four zone model was compared to the two zone model and literature experimental temperature value. The obtained indicated mean effective pressure (IMEP), thermal efficiency (η), cylinder pressure and emission characteristics from the developed model and those of two zone analysis were both compared with literature values.