An impact regime map for water drops impacting on heated surfaces

The impact morphology of millimetric water drops on a polished aluminium surface has been studied experimentally by high-speed imaging, for surface temperatures between 50 and 400 degrees C, and Weber numbers up to 160. Five impact regimes are defined based on the final outcome of the impact: three independent regimes (secondary atomisation, rebound, and splashing), and two mixed regimes (rebound with secondary atomisation and splashing with secondary atomisation). Impact regimes are displayed on a quantitative two-dimensional map, having the surface temperature and the impact Weber number at ambient conditions as coordinates. Some characteristics of the transition boundaries between impact regimes are discussed. (C) 2015 Elsevier Ltd. All rights reserved.