Hydrogen-diesel dual-fuel direct-injection (H2DDI) combustion under compression-ignition engine conditions
Patrick Rorimpandey, Ho Lung Yip, Aleš Srna, Guanxiong Zhai, Armin Wehrfritz, Sanghoon Kook, Evatt R. Hawkes, Qing Nian Chan
Abstract
This study investigates the ignition and combustion characteristics of interacting diesel-pilot and hydrogen (H2) jets under simulated compression-ignition engine conditions. Two converging single-hole injectors were used to inject H2 and diesel-pilot jets into an optically accessible constant-volume combustion chamber (CVCC). The parameters varied include fuel injection sequence, timing between injections, and ambient temperature (780–890 K). The results indicate that when diesel-pilot is injected before H2, with increasing time separation, the burnt diesel products mix and cool down, requiring longer jet-jet interaction to ignite the H2 jet. When H2 is injected before diesel-pilot, the H2-air mixing amount prior to pilot-fuel igniting impacts the combustion spreading through the H2 jet. If ignition of the H2 jet occurs beyond its end-of-injection (EOI), the H2 mixture zone where the pilot-diesel interacts with becomes too lean for combustion. At lower ambient temperatures, the combustion variability increases, attributed to the diesel-pilot lean out.