Experimental study of a liquid film flowing over a perforation

Perforations are one of the recognized geometrical features that contribute to liquid redistribution in corrugated sheet packings. Our experimental study focuses on a simplified but relevant configuration: thin film flowing either side vertical plate with circular perforation. We focus curtain mode when fills Confocal chromatic imaging reveals capillary ridge upstream perforation, an inertial downstream, and varicose wave standing curtain. show wavelength is selected such velocity both satisfies Taylor's dispersion relation matches local speed. examine effect perforation size, supply conditions, properties transition. Lastly, we propose simple model based momentum balance describes these parameters Reynolds number at which forms.