Characteristics of Gas-Dissolved Diesel Fuel Spray : (3rd Report, Spray Characteristics and Simulating Flash Boiling Process)

Abstract

The new injection system by using mixed fuel dissolved with liquefied CO₂ was proposed in this paper. Liquefied CO₂ was mixed into n-tridecane under pressurized state in order to promote the spray atomization and evaporation due to the effect of the flash boiling phenomena in fuel injection, and to control the combustion process due to the effect of internal EGR effect of CO₂ gas. Therefore, the simultaneous reduction of soot and NO_x cas be achieved effectively by use of this injection system. In this paper, the characteristics of diesel fuel spray dissolved with liquefied CO₂ were investigated quantitatively by means of several optical measurements. And the spray characteristics were revealed by the analysis of chemical thermodynamics. As a result, the atomization of this fuel is promoted due to the flash boiling much more than n-tridecane as the reference of the normal fuel and the spray structure is highly diHerent from that of the normal fuel.Moreover, thenumerical analysis for the atomization and the vaporization process wan carried out based on the flash boiling spray models.