Visualization of the end-gas auto-ignition phenomena of n-heptane in rapid compression machine

摘要

In this study,a newly designed center-ignited and partially visualized rapid compression machine was developed.End-gas auto-ignition phenomena were investigated using stoichiometric n-heptane/Air mixture under different initial temperatures by synchronized measurement of pressure and high-speed direct photography.The results showed that the initial temperature can greatly affect knock intensity and auto-ignition positon.One clear peak of the knock intensity was found around 660K.As the initial temperature increases,it was also found that there is a clear transition of the auto-ignition position from the flame front area to the chamber wall area.