화학공학소재연구정보센터
Atomization and Sprays, Vol.28, No.9, 797-809, 2018
A COMPARISON OF EVAPORATING SPRAY STRUCTURE OF JATROPHAMETHYL ESTER AND DIESEL, AND SURROGATE FUELS
In the present study, the spray characteristics of Jatropha methyl ester (JME), diesel, and two surrogate fuels, n-dodecane and n-hexadecane, are investigated under evaporating ambient conditions. A high-pressure chamber with optical access is used for the study. Nitrogen gas filled in the chamber is heated to reach a final pressure of 50 bar and a final temperature of 900 K. A single-hole nozzle with a hole size of 190 mu m has been used for fuel injection. The results showed that the liquid length of JME is longer by 19%, 17%, and 11% compared to that of diesel at injection pressures of 500 bar, 1000 bar, and 1500 bar, respectively. At a given operating condition, the vapor penetration of JME and diesel are observed to be similar. Two surrogate fuels, n-dodecane and n-hexadecane, with similar property differences as those between diesel and a typical biodiesel, have been studied. The results show that the liquid length of n-hexadecane is about 20% longer than that of n-dodecane whereas both fuels have similar vapor penetration. Thus, the surrogate fuels exhibit differences between spray characteristics similar to those of diesel and biodiesel. A separate comparison of spray characteristics of diesel and n-hexadecane showed that it is an acceptable spray surrogate for diesel. An analytical model for vapor penetration has been verified against the experimental data and found to match well with the data. A parametric variation of fuel density showed that the effect of fuel density variation is compensated by the corresponding variation in injection velocity at a given injection pressure, which explains the experimentally observed trend of similar vapor penetration of all the fuels