Experimental statistics of micrometer-sized water droplet deformation and breakup behavior in continuous air jet flow

Abstract

Fundamental study on breakup of the supercooled large droplet is important for understanding the microphysical phenomenon in aircraft icing. The deformation and breakup processes of water droplets with diameters in the range of 700 to 1000 microns injected into continuous air jet flow are investigated experimentally. Evolutions of the bag, the bag and stamen and the dual breakup morphology are recorded through the high-speed photography. Experiments are repeated 319 times to determine the statistics based dynamic behavior, including the mean deformation rate, velocity and duration. As concluded, minimum value of the droplet deformation rate in the x-direction increases from 0.46 to 0.72 when Weber number increases from 18 to 56. When the initial droplet breaks, the velocity of droplet tip is more than two times of the velocity of droplet terminal. Duration of the deformation stage accounts for about half of the total duration. Besides, a new interpretation of physical mechanism, combining effects of the aerodynamic drag, motion hysteresis and inertia, is proposed to explain formation and development of different deformation and breakup morphologies. This work is meaningful for the development of numerical simulation and theoretical models.