Penetration and break-up behaviour of a discrete liquid jet in a cross flowing airstream - A further study

The penetration and break-up characteristics of a discrete liquid jet injected into a high velocity cross flowing airstream were investigated as a basis of plain-jet airblast atomizer design. Aspects studied include the effects of liquid viscosity (0.001-0.125 Ns/sq m), liquid surface tension (0.027-0.74 N/m) liquid density (812-1830 kg/cu m), the liquid jet injection angle (30-90 deg), and the orifice length-to-diameter ratio (5-14). Among other findings, it was determined that, of the variables examined, only density exercises a noticeable effect upon the penetration behavior of a liquid jet. A reduction in the angle at which the liquid jet is injected relative to the airstream is found to reduce the sensitivity of the jet penetration to liquid and airflow conditions. The predictions of a previously-developed penetration model (Hussein et al., 1982) are determined to be in reasonable agreement with the experimentally measured penetration profiles. A correlation is obtained which can be used to predict with a reasonable degree of accuracy the Sauter mean diameter performance of a discrete liquid jet injected into a high velocity cross-flowing airstream. Minimum mean dropsizes are obtained in conditions when the liquid jet is injected at right angles to the airstream.