Abstract
Effects of the split injection on the D.I. gasoline spray characteristics were investigating by using the laser induced fluorescence (LIF) and the particle image velocimetry (PIV) techniques. The behavior of the spray and the air entrainment into spray induced by the spray motion were analyzed. In the split injection sprays, the development process of the 1st spray was similar to the single injection spray. However, the 2nd spray, which has the high axial velocity components and the low air resistance, caught up with the 1st spray and it continuously penetrated into the central parts of the 1st spray. The collision and coalescence between droplets took place during the penetration of the 2nd spray into the 1st spray, and these phenomena would change the internal structure of the spray. The spray development process varied with ambient pressures. The 2nd sprays stratified onto the tail part of the 1st spray at high ambient pressure.