Abstract
A laser 2-focus velocimeter (L2F) with a micro-scale probe was used for measurements of velocity, size, and vortex scale in diesel sprays. The focal diameter of the laser probe was about 3 μm, and the distance between two foci was 17 μm. The data sampling rate of the L2F system has been increased to 15 MHz. Investigated were diesel fuel sprays injected intermittently into the atmosphere from the injector with a nozzle orifice 0.113 mm in diameter. The injection pressure was set at 40 MPa by using a common rail system. Measurement position was located at 25 mm from the nozzle exit. It was found that the vortex scale estimated by the L2F was close to the one observed by image measurement.
