Analysis of Droplet Arrival Statistics for Droplet Clustering in Effervescent Spray: The Influence of Atomizer Internal Design

A novel convergent-divergent effervescent atomizer spraying water with air as atomizing medium was used to investigate the dependence of droplet clustering on atomizer internal design by the ideal spray theory of Edwards and Marx. Results demonstrated that all the size classes of droplets show the spray unsteadiness in effervescent atomization. Atypical example of an unsteady spray behavior is droplet clustering. The high number of deviation can be found for the small droplets at the edge of spray regardless of the atomizer internal design. No distinct relation about the droplet clustering behavior between all droplets and various droplet sizes in spray can be found. Low deviation can be obtained by increasing the diameter of incline aeration holes at air to liquid mass ratio (ALR) of 10%. The angle of incline aeration holes has no influence on the droplet clustering at ALR of 10%. The center region of spay showed high droplet clustering for a short mixing chamber atomizer at the ALR value above 0.58%.