Effect of Reynolds number on impact force and collision process of a low-velocity droplet colliding with a wall carrying an equal-mass deposited droplet

The impact force and collision process of a glycerol or aqueous solution droplet colliding with horizontal wall carrying an equal-mass deposited are presented. A piezoelectric sensor-based measurement platform, high-speed camera the volume-of-fluid numerical simulation method were used to measure explore underlying mechanism. Results indicate can be categorized into two regimes in terms Reynolds number, i.e. viscous regime inertial regime. For regime, high-pressure regions formed first at edge center droplet. Then high pressures will drop slowly. This results single-peak force–time curve. annular jet is between droplets, region generated falling on leads pressure rise then increases further, resulting second peak. key for occurrence double-peak curve sign number boundary about 101 107. single dimensionless peak decreases gradually changes slightly