Title : Spray characteristics of n-heptane blended with ethanol injected through a multi-hole type GDI injector
Authors : Jeong Hwan Park, Su Han Park, Mun Soo Chon, Young-Cheol Park,
Chang Sik Lee and Sungwook Park
Speaker : Jeong Hwan Park (MS course)
Abstract : The purpose of this study is to investigate the macroscopic spray characteristics of ethanol blended n-heptane fuel in a multi-hole gasoline direct injection (GDI) injector. In order to measure and analyze the spray characteristics, the spray visualization system was composed of a high speed camera, a metal-halide lamp, a fuel injection system, a the constant-volume high-pressure chamber. Furthermore, for analyzing effects of ethanol blending ratio on spray characteristics, four kinds of test fuels including pure n-heptane, E15, E50, E85 (wt, ethanol) were considered. The spray images from a spray visualization system were analyzed using a spray image processing program. The present image processing program provided spray
characteristics including spray tip penetration, spray area, and spray angle.
It was revealed that the increase of ethanol blending ratio caused the slow spray development due to high viscosity. These characteristic affected the decrease of the spray tip penetration and the spray area. However, it can be observed that the spray angle increased due to high vapor pressure in ethanol blending fuels. On the other hand, the increase of ethanol blending ratio diminished the difference of the spray characteristic by the ethanol blending.
Keywords: ambient pressure, ethanol blended fuel, GDI(Gasoline Direct Injection),
multi-hole injector, spray angle, spray area, spray tip penetration