Penetration and break-up studies of discrete liquid jets in cross flowing airstreams

The results of penetration and breakup studies of discrete liquid jets in cross-flowing airstreams are presented in order to aid the optimization of the plain-jet airblast atomizer design. The variables covered in the study included air stream velocity and density, liquid jet velocity, injection orifice diameter, l/d ratio, angular orientation, and spray medium. The tests were conducted under conditions of normal atmospheric pressure and temperature, using still photography for penetration profile and a laser light scattering technique for mean drop size determination. A penetration model was developed whose predictions are in reasonable agreement with experimentally measured penetration profiles. Varying the velocity of injected liquid appears to have no significant effect on the mean drop size, and analysis of the breakup data reveals the air stream velocity as exercising strong influence upon Sauter mean diameter.