Experimental investigation of single drop breakup in a confined turbulent wall-jet – Effect of Weber number

• Direct high-speed visualization is used to study drop breakup at varying We. • Increasing We, leads to higher breakup probability, and a faster breakup. • Breakup time and position correlates to when drops reaches the jet shear layer. • Local breakup rates increase with We; the location of the max has a We-dependence. This study uses an experimental scale-up model together with a high-speed camera setup to quantitatively study the effect of Weber number on the breakup probability, deformation time, breakup time, breakup position, and breakup rate in this geometry in a turbulent jet. Results show an increase in breakup probability and a decrease in deformation and breakup times with increasing Weber number. Breakup also occurs earlier with higher Weber numbers. Breakup time is predicted by the time it takes the drop to reach the intense turbulent stresses in the jet shear layers. Whereas breakup typically occur via a bulb-neck mechanism, drops are more chaotically deformed when breaking, if doing so at a higher Weber number. Breakup rates increase with Weber number. However, the position of the maximum local breakup rate is somewhat Weber number dependent. Results shed light on the breakup in these devices and can be used for validating breakup models.