Understanding of Knocking Occurrence Mechanism with CFD

Abstract

The aim of this paper is the understanding of knocking occurrence mechanism from the view of flame propagation behavior by using 3-D simulation with UCFM. The flame propagation behavior impacted by in-cylinder flow was analyzed by calculated results and experimental visualizations. The flows of tumble and swirl motion were given to in-cylinder by setting various baffle plates in the middle of intake port. The comparisons of the measured and calculated flame propagation behavior show good agreement for various conditions. The results indicate that in-cylinder flow varies flame propagation shape from initial combustion, and it has strong influence on knocking occurrence. In addition, the influence of chemical reaction in end-gas which is generated by the in-cylinder flow was analyzed.