Abstract
A laser 2-focus velocimeter (L2F) with a micro-scale probe was used for measurements of velocity and size of droplets in diesel sprays near the spray center 15 mm downstream from the nozzle exit. The injection pressure was set at 40 MPa by using a common rail injector. The data sampling rate of the L2F system has been increased to 15 MHz. The number density of droplets was estimated by data of velocity, size, and time interval between droplets. In the first half of hte injection period, the velocity of droplets which appeared later was higher than the velocity of droplets which appeared earlier. Large droplets with a relatively high number density were observed near the spray tip region.
