Diagnostic Measurements of Fuel Spray Dispersion

Plume shape, vaporization, droplet-size distribution, and number density of a solid-cone fuel spray were studied with both conventional and novel measurement techniques. Minor differences in spray plume shape were observed by measurements with photography, pulsed laser shadowgraphy, and in-line infrared spectroscopy. Laser Mie scattering showed the dispersion of small numbers of droplets beyond spray boundaries as determined by other measurements. A new optical method for nonintrusive, local, time-averaged measurement of vapor concentration, droplet-size distribution and number density within an axisymmetric spray is introduced. For the spray studied this method showed that vapor is confined to the spray plume and that vapor concentration and the concentration of small-diameter droplets exhibit analogous behavior.