Wladimir SARLIN (LadHyX)

Role of melting and solidification in the spreading of a water drop

Wladimir Sarlin¹, Rodolphe Grivet¹, Daniel-Vito Papa¹, Julien Xu¹,

Alexander Rosenbaum¹, Axel Huerre², Thomas Séon³, and Christophe Josserand¹

¹Laboratoire d’Hydrodynamique, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
²Laboratoire Matière et Systèmes Complexes, UMR CNRS 7057, Université Paris Cité, 75013 Paris, France
³Institut Franco-Argentin de Dynamique des Fluides pour l’Environnement, IRL 2027, CNRS, UBA, CONICET, Buenos Aires, Argentine

Understanding the physics at play during the spreading of a liquid droplet on a substrate is important due to the wide range of practical applications in which this situation occurs. This explains the significant research interest this topic has received during the last decades [1, 3]. A particular case is encountered when the liquid and the substrate temperatures are different: in such a scenario, phase change can be triggered during an impact over a solid surface and favours or hampers droplet spreading depending on whether melting or solidification is at play [2].

The talk will present experiments on water drop impact on ice or on cold brass substrate, in which both the liquid and substrate temperatures were varied alongside with the height of fall. The influence of temperature can be encompassed in the definition of an effective viscosity, which accounts for the modification of the developing boundary layer due to the phase change dynamics. The spreading ratio is then successfully predicted using similar laws as for isothermal drop impacts. This paves the way for exploring the impact of other liquids on their solid phases such as, for instance, for molten metal droplets. Furthermore, in the zero impact velocity limit, i.e., for water droplet deposition on ice, the phase change dynamics alters the spreading of the drop and the apparent angle of the resulting sessile droplet.

[1] X. Cheng, T.-P. Sun, and L. Gordillo. “Drop Impact Dynamics: Impact Force and Stress Distributions”. In: Annu. Rev. Fluid Mech. 54.1 (2022), pp. 57–81

[2] Z. Jin, H. Zhang, and Z. Yang. “Experimental investigation of the impact and freezing processes of a water droplet on an ice surface”. In: Int. J. Heat Mass Transf.  109 (2017), pp. 716–724.

[3] C. Josserand and S. T. Thoroddsen. “Drop impact on a solid surface”. In: Annu. Rev. Fluid Mech. 48 (2016), pp. 365–391