부산대학교 도서관

This work investigates the effects of ambient and injection parameters on the ignition and combustion characteristics of hydrogen (H2)–methane (CH4) jet (50% H2by volume, with the remaining CH4) in simulated direct-injection, compression-ignition conditions. Parameter variations include ambient gas temperature (1060–1200 K), ambient oxygen (O2) concentration (10–21 vol %), and injection pressure (10–20 MPa reservoir pressure). The results show that the ignition delay of the H2–CH4jet decreases with increasing ambient temperature. In most cases, the ignition initiates from a localized kernel before spreading across the jet volume downstream. The lower ambient O2cases display a more voluminous ignition sequence. The results also show that the jet flame recesses upstream to attach or stabilize close to the nozzle but becomes increasingly lifted with lower ambient temperature and O2conditions. The flame autoignition process displays increased variation at the lowest tested ambient temperature condition in this work, which affects the ensuing flame evolution and heat release profile.