Spray Characteristics of Liquid Jet Traversing Subsonic Airstreams

The spray characteristics of a liquid jet traversing subsonic airstreams were experimentally investigated. The disintegration phenomena of liquid jets were observed by instantaneous photographs and high-speed video movies. The waves on the liquid jet surface are three dimensional and show very complicated behaviors. These waves are an important cause of the liquid jet disintegration. Droplet mass e uxes were measured using an isokinetic sampling probe. Empirical equations of their distributions that are expressed by the standard normal function were deduced. Droplet sizes and droplet velocities were measured by a phase Doppler particle analyzer. At low air velocity, the mean droplet diameter reaches its maximum in the peripheral mixing region. At high air velocity, however, the mean droplet diameter reaches its maximum in the core region. The droplet velocity peaks in the peripheral mixing region over the whole range of the air velocity.