Experimental study of sizes and velocities of the droplets produced by water injection system with compressed-air atomizer into the intake manifold of an internal combustion engine applying the optic methods

The paper studies the quality of water spraying by system with a compressed-air atomizer designed for water injection into the intake manifold of an internal combustion engine. The system consists of a two-cylinder piston compressor providing compression of water-air mixture in the working chambers. The piston compressor has connection to the atomizer through long channels. The droplet sizes were measured through automatic image processing by the Shadow Photography method. The droplet velocity field was measured by 2D-PIV method. Experimental results demonstrated that the injection system offers a high quality of atomization for the air/water mass ratio higher than 0.46. The Sauter mean diameter was no more than 31.1 µm.