Different from traditional engine test, an optical constant volume chamber simulated HTHP ambient condition was employed by using biodiesel-diesel-butanol blends. With high-speed camera and synchronized copper vapor laser, recorded fuel spray and combustion process, measured liquid jet penetration length and heat release rate under variable ambient temperature and fuel composition conditions. With ambient temperature increasing, burn process converted from premixed combustion to diffusion combustion, and the micro-explosion became weak and disappeared. It was concluded that micro-explosion could occur under particular initial ambient temperature and specific blend ratio conditions for the biodiesel-diesel-butanol fuel, that will distinctly enhance fuel evaporation and premixed combustion process.
Yu Liu;骏 李