Fuel-Spray Formation

Experiments are described in which the diameters of the fuel drops in sprays from different types of nozzles were measured and the effects of fuel-injection pressure, nozzle dimensions, and the density of the chamber air on the atomization of the sprays were determined. A simple method of determining the size and form of the high-velocity parts of sprays is also described. High-speed spark photographs of fuel sprays are shown that were made with lens systems having magnifying powers of 0.5, 2.5, and 10. These photographs reveal the process by which the fuel is transformed from the solid jet to the atomized spray, and also show the effect of several factors on spray dispersion.