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

more »

... nt 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.