Spray generation

Abstract

This is an experimental investigation of the ligaments and drops generated at the free surface of liquid wall jets and liquid axisymmetric jets flowing over sand and polystyrene (beads) roughed surfaces. Experiments were conducted with freshwater and Eulerian and Lagrangian methods of description were used in the analysis. Measurements were made with three different high- speed imagers and two different pulsating laser systems and analyzed with appropriate image analysis software. The liquid jet Reynolds number ranged from 3.5x1O(4) to 8.5xlO(4), the Froude number from 8 to 30, and the Weber number from 2,000 to 7,500. The vertical positions, velocities and accelerations of several ligaments from inception to drop formation as well as the characteristics of the droplets were determined from the digitized images. These are expected to lead to a better understanding of the formation and the ejection of the eddies from the turbulent jet beneath the free surface