Operational feasibility of a spark ignition engine which is subjected to VTEC management strategy

Abstract

ABSTRACT A validated spark ignition engine combustion model was used to investigate the operational feasibility of subjecting a 5.734 l, V8 engine to the Honda variable (valve) timing and electronic lift control (VTEC) management strategy. The numerical results were found to be in good agreement with measured data during the compression and expansion strokes. However, the results of the numerical model overestimated the measured data by approximately 10%–15% during the combustion phase. The reason for this discrepancy could be due to the fact that the turbulence levels within the combustion chamber during the experiment was not specified. Therefore, we accounted for turbulence in the simulation with a flame speed multiplying factor, . The investigations cover operations at low, mid-range and full power periods; for fuel-air equivalence ratios, of . The results of the study show that operational viability of a 5.734 l, V8 engine when subjected to the VTEC engine management scheme was achievable, provided high levels of turbulence were maintained, especially for extra lean mixtures, that is, for fuel-air equivalence ratio, . This work shows that the values of the flame speed factor, have to be carefully selected in order to achieve complete combustion.