Investigation of Flame Propagation Behavior under Conditions with Autoignition in Constant Volume Chamber

Abstract

Elucidation of knocking is indispensable to further improve the thermal efficiency of gasoline engines. In this study， we investigated the auto-ignition phenomenon in a high temperature and high pressure environment using a constant volume chamber. We are conducting experiments with Φ=1.4 using n-heptane， and we are studying from visualization of flame and pressure history. At Φ=1.4， pressure oscillation with strong resonance frequency， three types of combustion patterns， and the combustion process until auto-ignition occurred were confirmed. It was suggested that the phenomenon of early combustion had an influence on the presence or absence of knocking.