Individual droplets of several liquids are generated at the tip of a needle and fall by action of gravity onto the impact surfaces. The targets are accommodated on a cooper block heated by a cartridge heater. The temperature is monitored by thermocouples type K and controlled with a PID temperature controller.
Surfaces are heated from ambient temperature up to 300ºC to study droplet behaviour within the various boiling regimes.
The impact conditions cover a wide range of Weber, Reynolds and Ohnesorge numbers by altering liquid properties, droplet diameter and impact velocity. The impact angle ? varies from 6º up to 90º. The experiments consider numerous target plates made of different materials and with different surface topographies. Enhanced target surfaces with regular roughness profiles are used to study the effect of roughness amplitude and fundamental wavelength (distance between the grooves) in droplet dynamics.
