In this paper, the fluorescent method is used in conjunction with the shadowgraph method to obtain the concentration distributions and droplet sizes in the spray. A beam of light from a pulsed laser, passing through a longitudinal or cross-section of a jet of atomized fuel, tinted with a fluorescent additive, oxyquinoline, partially scatters on droplets (Mi-scattering), while blue light with a wavelength λ = 488 nm excites fluorescence in the green range of the wavelength spectrum. A color image of the cross section of the fuel spray by a laser beam is recorded during scanning by a digital camera, the optical axis of which is directed at a right angle to the axis of the laser beam. Thus, at each point of the image of the spray cross section, fluorescence intensities are recorded, proportional to the volume concentration of the droplets and vertically polarized by the component scattered on the light drops with respect to the scattering plane (measurement). The ratio of fluorescence intensity to Mie scattering intensity is proportional to the diameter of the fuel droplets averaged over the Sauter.
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