Dispersion of spray from swirl nozzles

Abstract

Atomization and dispersion of a liquid in the form of a spray from an atomizing nozzle is associated firstly with the disintegration of a high speed thin liquid sheet into droplets and then with the dynamics of those droplets in the surrounding atmosphere. In the present work a theoretical model has been set up to evaluate the droplet trajectories of an atomized spray from a swirl nozzle as a function of the liquid properties, injection conditions and geometrical dimensions of the nozzle. The theoretical model is based on the analytical solution of the internal hydrodynamics of the nozzle followed by the dynamics of droplets in a stagnant atmosphere. Experiments have been conducted to determine the drop size distributions and the spatial mass flow distribution of the spray. The pertinent governing parameters regarding the spray dispersion are the liquid velocity, viscosity and surface tension of the liquid, the density of the ambient atmosphere and the geometrical dimensions of the nozzle.