Trajectory of a Liquid Jet Traversing Subsonic Airstreams

Introduction F UEL-JET penetrationis especiallyimportant in regardsto combustordesignand in understandingthe physicsof liquid-jetdisintegration.Thomas and Schetz1 researchedabout the spray characteristicsof a liquid jet traversingsupersonicairstreams.They studied liquid-jet penetrations,mean droplet diameter proŽ les, and droplet mass- ux proŽ les. Inamuraand coworkers andOda et al. studied jet penetration, jet width, and the spray characteristics in subsonic airstreams.Tsau et al. numericallyanalyzedthebehaviorof a liquid jet that had been transversely injected into subsonic airstreams.Wu et al. deduced the semi-empiricalequation of liquid-jetpenetration traversingsubsonicairstreams.They estimated the drag coefŽ cients of a liquid jet by using jet-penetrationmeasurements. There has been a great deal of research on the trajectories of liquid-jet traversingsupersonicairstreams.However, there has been little done on the theoretical analysis of the trajectory of a liquid jet traversing subsonic airstreams. The objective of this paper is to semitheoreticallydeduce a simpliŽ ed equation for the trajectory of a liquid jet traversing subsonic airstreams, which is useful for the easy design of a combustor.