Abstract
A laser 2-focus velocimeter (L2F) was used for measurements of velocity and size of droplets in diesel sprays. The L2F had a micro-scale probe which consists of two foci. The data sampling rate of the L2F system was markedly high as 15MHz. Fuel sprays were injected intermittently into the atmosphere by using a common rail injector. The orifice diameter of the injector was 0.112mm and 0.135mm. The rail pressure was set at 135MPa. Measurement positions were located in the plane of 10mm downstream from the exit of the nozzle orifice. The results showed that the size of spray droplets injected from larger orifice was larger than that injected from smaller orifice. The number density of spray droplets injected from larger orifice was lower than that injected from smaller orifice except at the spray center. The number density of spray droplets at the spray center was smaller than at other positions on both injector.
