Numerical Simulation of Two-Dimensional Combustion Process in a Spark Ignition Engine with a Prechamber using k <italic>-</italic> ε Turbulence Model

Two-dimensional combustion processes in a spark ignition engine with and without an unscavenged horizontal prechamber are calculated numerically using a k-e turbulence model, a flame kernel ignition model and an irreversible reaction model to obtain a better understanding of the spatial and temporal distributions of flow and combustion. The simulation results are compared with the measured results under the same operating conditions of experiments, that is, the minimum spark advance for best torque (MBT), volumetric efficiency of 80±2 %, air-fuel ratio of 15 and engine speed of 1000 rpm, with various torch nozzle areas and an open chamber.

Consequently, the flow and combustion characteristics calculated for the S.I. engine with and without prechamber are discussed to examine the effect of torch jet on the velocity vectors, contour maps of turbulence and gas temperature. Furthermore, the calculated mass burned fraction and pressure diagram are found to be in reasonable agreement with the measured ones.