Droplet Deformation and Breakup

Abstract

Following formation, droplets may enter a region where aerodynamic forces are large enough to cause significant deformation and breakup. When a droplet breaks apart into a multitude of small fragments due to disruptive aerodynamic forces, the process is termed secondary atomization. This has been a rich area of study for many years and a number of in-depth reviews are available [1–4]. Here, the most important findings are discussed. The chapter is divided into two sections: Newtonian and non-Newtonian liquids. Droplets may be accelerated from rest gently or by a near step change in relative velocity. Experimentation has shown that the breakup is different in each case. The first case is found in nature and plays an important role in rain storms. However, the latter is more likely to occur in sprays. For this reason, this chapter considers only breakup due to step changes in relative velocity.