Journal Article

Phase diagram for droplet impact on superheated surfaces

Riboux, Guillaume, Geerdink, Bart, Lohse, Detlef, Staat, Hendrik J. J., Gordillo, José Manuel, Sun, Chao, Tran, Tuan

2015

Overview

We experimentally determine the phase diagram for impacting ethanol droplets on a smooth, sapphire surface in the parameter space of Weber number $\\mathit{We}$ versus surface temperature $T$ . We observe two transitions, namely the one towards splashing (disintegration of the droplet) with increasing $\\mathit{We}$ , and the one towards the Leidenfrost state (no contact between the droplet and the plate due to a lasting vapour film) with increasing $T$ . Consequently, there are four regimes: contact and no splashing (deposition regime), contact and splashing (contact–splash regime), neither contact nor splashing (bounce regime), and finally no contact, but splashing (film–splash regime). While the transition temperature $T_{L}$ to the Leidenfrost state depends weakly, at most, on $\\mathit{We}$ in the parameter regime of the present study, the transition Weber number $\\mathit{We}_{C}$ towards splashing shows a strong dependence on $T$ and a discontinuity at $T_{L}$ . We quantitatively explain the splashing transition for $T

• Publisher: Cambridge University Press
• Subject: Contact / Droplets / Ethanol / Ethyl alcohol / Fluid mechanics / Parameters / Phase diagrams / Physical properties / Rapids / Splashing / Surface temperature / Temperature / Transition temperatures / Weber number