Parametric Study of Jet Spray Behavior in an Air Cross Flow

The aim of this paper is to investigate how the features of the atomization process of a liquid jet injected into a high- pressure air cross flow depends on parameters such as air velocity, liquid velocity and diameter of the nozzle. The main features of the spray morphology have determined by means of a tomographic visualization technique and the general evolution of the spray in some typical cases is presented in the paper. It is shown as the jet evolution is significantly influenced by the onset of a stripping atomization mechanism marked by the peculiar morphology of the spray cross section. This is also evident from the observation of the jet trajectories determined by using a shadowgraphic technique. The different behavior of the atomization process induced by the stripping mechanism led to a bi-stable evolution of jet trajectory in dependence of the prevalence of the liquir or air velocities effects. This feature can be hardly modeled by the interpolating function proposed in the literature. As a consequence, a stronger effort to gain a deeper understanding of the fluid dynamic, involved in the jet break-up in presence of an air cross flow, is still required in order to build-up a more realistic model of the jet trajectory evolution.