Dynamic behaviors during a single liquid drop impact on a static drop located on spheres

Experimental observations during a single liquid drop impinging onto a static hemispherical drop on steel spheres are performed using a high speed digital camera at 10,000 frames per second. The sphere-drop curvature ratio ranges in 0.139-0.558 and the 30 vol.% glycerol/water solution and water are selected as experimental fluids. By increasing the Weber number, experimental observations present outcomes of rebound, coalescence, and the circular liquid sheet successively. The circular liquid sheet diameter increases with the Weber number and Reynolds number. With the decrement in the curvature ratio, the liquid sheet diameter varies less at the initial stage, while after the maximum value, the smaller curvature ratio will lead to the larger liquid sheet diameter. (C) 2013 Elsevier Inc. All rights reserved.