Prediction of drop size distribution in a spray from a pressure swirl atomizer using maximum entropy formalism

Abstract

Drop size distribution is an important characterizing parameter of a spray. In the present work a theoretical model has been described, based on the maximum entropy formalism principle, for the determination of the drop size distribution in a spray issued from a pressure swirl atomizer. The atomization efficiency is also derived from the model, assuming the velocities of all the drop sizes to be uniform. The results show that the drop size distribution, described from the present model, resembles the Rosin-Rammler type distribution very well, with a dispersion parameter of 3.47. The atomization efficiency is found to decrease with the increase in liquid mass flowrates, when the pressure differential across the atomizer remains the same. On the other hand, an increase in the orifice diameter increases the atomization efficiency, when the liquid mass flow rate and pressure differential are the same. The ratio of the surface energy to the kinetic energy at the atomizer exit is seen to influence the atomization efficiency.