Water drop impact on a semi-cylindrical convex hot surface for a diameter ratio of unity

Abstract

When a liquid drop impacts on a hot non-flat surface the curvature of the surface and its geometrical characteristics transmute the physical regimes and their boundary compared to a flat surface impact. The present experimental study is focused on water drop impingement on a mimetic solid semi-cylindrical convex hot surface, with a size equal to the drop. The thermal versus inertia map of generated regimes is obtained, while some well-known regimes associated with a flat surface are not observed for the present non-flat impacts. These include rebounding of the main drop and atomization which are common observed phenomena when the hot surface is flat. The maximum spreading of the droplet is measured at different surface temperatures and impact Weber numbers. In directrix direction it is independent of temperature at both partial contacted and breakup regions but reduces upon transitioning at high Weber numbers. The maximum spreading scaling with the impact Weber number is obtained along both directrix and generatrix directions. Finally, since the spreading is asymmetric, its aspect ratio is obtained and has shown a considerable rise at partial contacted high Weber numbers.