Title screen

The velocity field inside a droplet located on a horizontal wall at a temperature of Tω = 81°C has been studied experimentally while another droplet falls at a temperature of 22°C. Most studies were performed either with a single droplet or a spray of droplets. Velocity field measurements were performed using particle image velocity. This work shows that at the moment of interaction between the two drops the average velocity in the drop increases by 2-8 times, and the fluctuations of the maximum instantaneous velocity (velocity pulsations) are 20 times higher than the average value. The influence of graphite particles and surfactant (OP-10, LLC "Sintez OKA", Dzerzhinsk, Russia) on the velocity change inside the drop has been investigated. The graphite particles practically do not change the velocity field, and the surfactant reduces the velocity jump by several times as the drops merge.