On the Splashing Threshold of a Single Droplet Impacting onto Rough and Porous Surfaces

Abstract

Drop impact onto rough and porous surfaces is found in manifold applications such as ink jet printing and irrigation. An experimental work is carried out in order to classify different splashing outcomes of water and isopropanol droplets impacting onto various structured and unstructured rough and porous surfaces. The roughness of the surfaces is characterized with internationally standardized horizontal and vertical statistical roughness parameters. An empirical relationship is developed to describe the splashing threshold on rough surfaces. Further differences in the splashing threshold of porous surfaces are presented.