Study on Influences of Flame Temperature on Premixed Flame and End Gas in Process of Knock using Constant Volume Vessel

Abstract

Influences of flame temperature on knock occurrence process in a constant volume vessel were investigated in this study. Flame temperature was varied by Ar dilution to the mixture. Mixture composition was determined so that adiabatic compressed temperature of end gas was almost constant. Cool and blue flames were observed in front of the propagating flame before the occurrence of pressure oscillation at all of the experimental conditions. Knock occurrence process may be sensitive to temperature distribution in the end gas which is affected by heating near the flame and cooling at the chamber wall. Then unsteady 1D numerical simulation using detailed reaction mechanism was carried out in order to investigate the temperature distribution in the end gas. The occurrence of cool and blue flames observed before the knock occurrence might be affected by temperature distribution in the end gas.