title: Capillary interception of floating particles by surface-piercing vegetation.
abstract: Surface-piercing vegetation often captures particles that flow on the water surface, where surface tension forces contribute to capture. Yet the physics of capillary capture in flow has not been addressed. Here we model the capture of floating particles by surface-piercing collectors at moderately low Reynolds numbers (Re<10). We find a trade-off between the capillary force, which increases with the collector diameter, and the relative size of the meniscus, which decreases with the collector diameter, resulting in an optimal collector diameter of ~1-10 mm that corresponds to the regime in which many aquatic plant species operate. For this diameter range the angular distribution of capture events is nearly uniform and capture can be orders of magnitude more efficient than direct interception, showing that capillary forces can be major contributors to the capture of seeds and particulate matter by organisms.
authors.affiliation: Dipartimento di Ingegneria Civile, Edile e Ambientale, University of Padova, Via Loredan 20, 35131 Padova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Peruzzo
authors.forename: Andrea
authors.initials: A
authors.lastname: Defina
authors.forename: Heidi M
authors.initials: HM
authors.lastname: Nepf
authors.forename: Roman
authors.initials: R
authors.lastname: Stocker
mesh_terms: D000818:Animals; D000852:Anopheles / Q000737:chemistry; D059001:Aquatic Organisms / Q000737:chemistry*; D002197:Capillary Action; D031255:Carex Plant / Q000737:chemistry; D017753:Ecosystem; D057927:Hydrophobic and Hydrophilic Interactions; D008954:Models, Biological; D008956:Models, Chemical; D010944:Plants / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water