High Speed Imaging Reveals a Close Resemblance Between Drop Impacts on a Solid Surface and the Interaction of a Cold Droplet Placed Inside a Hot Liquid

The phenomenon of drop impacts on a solid surface and the interaction of a cold droplet with a hot liquid pool are both of great relevance in many practical and engineering situations. Most of the reported research in the literature on these phenomena focus either on the impact of a droplet on a solid surface or a liquid surface and there are hardly any study on the interaction of a stationary cold droplet with a hot pool of liquid. This study reports high speed flow visualization of a drop impact on a Teflon-coated solid surface at different liquid properties and impact Reynolds number. Simultaneously, high speed imaging of the interaction of a cold droplet with the hot olive oil pool has also been carried out with a high intensity continuous light source. The images show a striking resemblance between the flow dynamics of the two phenomena. A comparison between the two phenomena is made and suggestions are made for the possible underlying physics.