The Effects of Gasoline-Biodiesel Blended Fuels on Spray Characteristics and Engine Combustion.

The effects of Gasoline-Biodiesel Blended Fuels on Spray Characteristics and engine combustion Sakda Thongchai1, Yunho Jeong1, Ocktaeck Lim2* 1 Graduate School of Mechanical Engineering, University of Ulsan, Mugeo-dong, Nam-gu, Ulsan 680-749, Korea 2* School of Mechanical Engineering, University of Ulsan, Mugeo-dong, Nam-gu, Ulsan 680-749, Korea * Key words : Gasoline-Biodiesel Blended, Spray Characteristics, Shadowgraph *Corresponding author¡¯s, E-mail: otlim@ulsan.ac.kr The high demand of petroleum base fuel conjuction with the decresing its resource has been stimulated many researchers to investigate the new source of energies such as alternative fuels. Biodiesel has been successfully applied in many countries. However, the application has been limited in only the compression ignition engines. Therefore, it is interesting to use biodiesel in other types of engine, for instance, homogeneouse charge compression ignition (HCCI) or gasoline conpression ignition (GCI) engines [1]. The current study has been investigated the effects of biodiesel blended with gasoline fuels on spray charcteristics in a GCI engine. With the concentration of 5, 10, 15 and 20% by volume as shown in Figure 1, biodiesel was blended with commercial gasoline and performed macroscopic visualization test. Pure gasoline and biodiesel were also tested as the reference. As shown in Figure 2, shadowgraph technique [2] was conducted in the constant volume chamber and recorded by a high speed video camera with frame speed 10,000 f/s. Fuel injection was set 800, 1000 and 1,350 bars at 1,500 and 2,000 rpm. The spray angle and spray penetration tip were measured and analyzed by image processing [3,4]. The results showed that when injection pressures were increased the spray penetration tip incresed. Also, spray cone angle slighty increased. The effects of engine speed on the spray charcteristics could not be obserbed clearly. Pure gasoline presents the highest spray penetration tip but narrower when compared with blended fuels.