Optimization of gasoline-dissolved CO₂ injectors

An experimental study on flashing injection of gasoline-dissolved CO ₂ mixtures through specially designed injectors was performed. The injectors used comprised an expansion chamber, prior to the discharge orifice, in order to promote the CO₂ flashing. Malvern Mastersizer-X was used to measure the spray characteristics. High-speed digital video camera was employed to visually register the expansion chamber flow patterns. The geometry of the expansion chamber was optimized to produce minimum SMD. The high-speed camera photographs, have revealed the different flow regimes inside the expansion chamber under different operation conditions, and thus provided a solid ground to explain the relationship between the optimal chamber dimensions, the operation conditions, and the observed characteristics of the spray.