Measurement of droplets in high number density spray near common rail injector nozzle by micro-probe Laser2Focus

摘要

An L2F with micro-scale probe was used for the measurements of the velocity and size of droplets in a diesel fuel spray near the spray center 30 mm downstream from the nozzle exit. The injection pressure was set 40 and 70 MPa by using a common rail injector. Droplets' light scattering signal was detected just after the spray tip reached the measurement position. With the increase in injection pressure, the droplet velocity increases and the droplet size decreases. It is understood that the droplet's number density increases with rail pressure and disintegrated droplets tend to fly in the direction perpendicular to the spray axis.