DROPLET SIZE AND VELOCITY MEASUREMENTS IN A SPRAY

Current emphasis on improving performance and reducing emissions in direct injection compression ignition (Diesel) engines demands detailed understanding of high pressure transient sprays. Combustion studies require quantitative information, specifically local droplet sizes and velocities, throughout the spray field. The extreme environment inside the combustion chamber and the turbulent, unpredictable nature of the fuel sprays complicate the analysis of the spray field. This paper discusses the joint implementation of a diffraction-based droplet sizing diagnostic and particle image velocimetry (PIV) on a high pressure spray. These diagnostics, used together, provide spatial maps of local droplet sizes and velocities in the spray.