Dynamic characteristics of moving droplets impacting sessile droplets with different Reynolds numbers

The collision of moving droplets with sessile droplets is a common occurrence in fields of industry, including power generation, chemical engineering, and aerospace, among others. In this paper, the collision of propylene glycol, glycerol, and de-ionized water droplets is studied for given collision speeds and different volume ratios of moving and sessile droplets using high-speed photography. It is found that droplet collision at a speed of about 0.25 m/s leads to compression deformation, whereas collision at about 1.10 m/s typically produces features, such as a non-splashing liquid crown and a central liquid jet. In this paper, the main characteristics of the above phenomena are quantified, the influence of the Reynolds number at different volume ratios is studied, and the main phenomena are explained from the perspective of an energy analysis. The findings reported here are significant for the solution of practical engineering problems and improving the stability of equipment operation.