ICOPE-15-1064 A fundamental study on breakup patterns of water film splashed into air flows

Abstract

Breakup patterns splashed from a plate edge which is set in parallel air flows are observed by a high speed camera in a fundamental study on breakup of a water film. The experiments were done using air flows with maximum velocity of 127 m/s and water supplied by city water. Breakup patterns of the water film change with the Mach number of the air flows and the relative Weber number which is expressed by the water film thickness taken as the reference length. In the low Mach number region, droplet-type patterns appear. In the high Mach number region, sheet-type patterns are observed. In the mid Mach number region, droplet-type, string-type, thrown-net-type, and sheet-type breakup patterns can be seen. The thrown-net-type breakup pattern is a unique breakup pattern that is not observed in a single droplet breakup. When the relative Weber number increases, the transition to the sheet-type pattern begins earlier than that at the low relative Weber number. Water film breakup patterns can be classified on a map based on the Mach number and relative Weber number within the experimental ranges of this study. Some correlations between wave patterns on the surface of the water film and breakup patterns of the water film are also observed.