Freezing of a Suspended Supercooled Droplet with a Heat Transfer Mixed Condition on Its Outer Surface

• Main Authors: Tabakova, S, Feuillebois, F, Radev, S
• Format: Conference Proceeding
• Language: English
• ISSN: 0094-243X
• DOI: 10.1063/1.3265335

The problem of water droplets freezing before or after their impact on solid surfaces is of major importance when modeling the aircrafts icing in wind tunnels. The object in this study is to estimate the freezing time of a suspended supercooled droplet in an air flow. It is known that freezing occurs into two steps: a short stage of rapid return to thermodynamic equilibrium, when the droplet becomes a water-ice mixture and a longer stage of its complete freezing. Mathematically, the second freezing step can be modeled by the one-phase Stefan problem. A convective heat transfer with ambient air is modeled here by a mixed boundary condition on the droplet outer surface. Assuming a spherical droplet, an asymptotic solution is developed for small Stefan numbers, while for arbitrary Stefan numbers a numerical solution based on the enthalpy method is constructed. Both solutions are compared. The numerical solution is also compared with other authors experimental results.