An experimental investigation on two-stage low-temperature heat release in iso-octane auto-ignition

A recent computational study showed that iso -octane exhibits a two-stage heat release behavior in the first-stage low temperature ignition regime under certain ranges of initial temperatures and pressures. To explore this computational result, ignition delay time measurements were conducted using a rapid compression machine (RCM) at three different conditions. The experimental observations indeed substantiate the computational results of two-stage heat release in the low-temperature auto-ignition process. Comparison between experimental measurements and simulation results using three different reaction models was also conducted, showing closeness in the timing and intensity of the two-stage heat release for two of them.