High Speed Visualization of Droplets Impacting with a Dry Surface at High Weber Numbers

Abstract

The focus of this article is to describe the evolution of the spreading diameter and secondary droplets generated by splashing. High-speed visualization was used to study the time evolution of water droplets impacts with dry surfaces at Weber numbers between 3,500 and 10,000. Different prediction models of the maximal spreading diameter have been compared with each other and with the experimental data. A similarity between the spreading rates was observed in the last stage of the impact at high Weber numbers. The time evolution of the secondary droplets and the formation of the crown was observed and analyzed at the different Weber numbers.

On the splashing of high-speed drops impacting a dry surface

“…Nevertheless, the effect of the liquid properties on the magnitude of the velocity is rather small. Our measurements demonstrate that the evolution of the average velocity follows the dependence u ∼ 1/ √ τ predicted by the RG theory within (4.2) and measured in Thoroddsen et al (2012) and Burzynski & Bansmer (2018). This theoretical approach together with the experiments presented here indicate that the mean velocity of secondary droplets appears to be close to universal for high-speed impacts, as shown in figure 14(a).…”

Role of surrounding gas in the outcome of droplet splashing

“…(2) and (3) is also predicted by theory. This reinforces the previous observation made by different authors, where U ∼ τ −1/2 [6,7,28]. Contrary to the droplet size and horizontal velocity, the vertical velocity of the droplets u y,s is strongly affected by the gas, as can be seen in the evolution of the angles in Fig.…”