Morphology of boiling induced secondary atomisation by liquid impact on inclined walls

The impact of single water drops on heated walls is experimentally investigated. The effects of the surface temperature, the impact angle and the wall effusivity on the impact morphology and the secondary atomisation are analysed by means of a high resolution CCD camera. Two boiling induced secondary atomisation (bubble boiling and film boiling atomisation ) were evidenced and the wall effusivity was found to have an effect on the time scales of both secondary atomisation regimes. The impact angle (from 90° - normal impact - to 6°) plays a fundamental role in defining the spatial distribution of the secondary droplets for the bubble boiling regime and in characterizing the break-up of the levitated spreading lamella for the film boiling regime.