In order to study subsequent development of collided droplets in impinging streams

a high-speed digital camera system

consisting of laser point source and high-speed digital camera

and a gas-liquid two-phase experimental platform was designed. The high-speed digital camera system was used to record droplet coalescence or secondary atomization caused by collisions in coaxially opposite gas-liquid two-phase impinging streams. Images of droplet movement were processed to analyze influence of droplet size

velocity

viscosity

and impact angle on collision outcomes. The results showed that droplets would be busted upon collision with unlimited increase in size and velocity. As surface tension was increased but viscosity and Ohnesorge number were decreased

inlet droplets were more inclined to break. Under experimental conditions

droplets upon collision were coalesced when moved coaxially in the same direction

were stretchily separated when moved in a certain angle

and were reflexively separated or busted moved coaxially in the opposite direction.