HCCI 엔진용 스월 인젝터의 분무 특성에 관한 연구

Abstract

This paper describes spray characteristics of a swirl injector which is intended for use in a HCCI engine. Many optical diagnostics such as laser diffraction and phase Doppler methods, and high speed camera photography are applied to measure the spray drop diameter and to investigate the spray development process. The drop sizing results of the laser diffraction method were compared with those of a phase Doppler particle analyzer (PDPA) to validate the accuracy of experiment. In addition, the effect of fuel properties on the spray characteristics was investigated using three different fuels because HCCI combustion is tolerant of the chemical composition of various fuels. From these results, the HCCI injector formed a hollow cone sheet spray rather than a liquid jet and the atomization efficiency is high for the low-pressure injector. The SMD of test injector was ranged from 15 μM to 30 μM We also found that the spray breakup characteristics were dependent on the fuel properties such as density, viscosity, and surface tension. The breakup time of normal heptane is shorter than that of gasoline and diesel fuel and the SMD of this fuel is smaller than other fuels.