Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.

Vortical cross-step filtration in suspension-feeding fish has been reported recently as a novel mechanism, distinct from other biological and industrial filtration processes. Although crossflow passing over backward-facing steps generates vortices that can suspend, concentrate, and transport particl...

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Main Authors: Hannah Brooks, Grant E Haines, M Carly Lin, S Laurie Sanderson
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2018-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC5862459?pdf=render
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author Hannah Brooks
Grant E Haines
M Carly Lin
S Laurie Sanderson
author_facet Hannah Brooks
Grant E Haines
M Carly Lin
S Laurie Sanderson
author_sort Hannah Brooks
collection DOAJ
description Vortical cross-step filtration in suspension-feeding fish has been reported recently as a novel mechanism, distinct from other biological and industrial filtration processes. Although crossflow passing over backward-facing steps generates vortices that can suspend, concentrate, and transport particles, the morphological factors affecting this vortical flow have not been identified previously. In our 3D-printed models of the oral cavity for ram suspension-feeding fish, the angle of the backward-facing step with respect to the model's dorsal midline affected vortex parameters significantly, including rotational, tangential, and axial speed. These vortices were comparable to those quantified downstream of the backward-facing steps that were formed by the branchial arches of preserved American paddlefish in a recirculating flow tank. Our data indicate that vortices in cross-step filtration have the characteristics of forced vortices, as the flow of water inside the oral cavity provides the external torque required to sustain forced vortices. Additionally, we quantified a new variable for ram suspension feeding termed the fluid exit ratio. This is defined as the ratio of the total open pore area for water leaving the oral cavity via spaces between branchial arches that are not blocked by gill rakers, divided by the total area for water entering through the gape during ram suspension feeding. Our experiments demonstrated that the fluid exit ratio in preserved paddlefish was a significant predictor of the flow speeds that were quantified anterior of the rostrum, at the gape, directly dorsal of the first ceratobranchial, and in the forced vortex generated by the first ceratobranchial. Physical modeling of vortical cross-step filtration offers future opportunities to explore the complex interactions between structural features of the oral cavity, vortex parameters, motile particle behavior, and particle morphology that determine the suspension, concentration, and transport of particles within the oral cavity of ram suspension-feeding fish.
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spelling doaj.art-5c2e46d917b842678838cee90aa7ccce2022-12-22T01:26:08ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-01133e019387410.1371/journal.pone.0193874Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.Hannah BrooksGrant E HainesM Carly LinS Laurie SandersonVortical cross-step filtration in suspension-feeding fish has been reported recently as a novel mechanism, distinct from other biological and industrial filtration processes. Although crossflow passing over backward-facing steps generates vortices that can suspend, concentrate, and transport particles, the morphological factors affecting this vortical flow have not been identified previously. In our 3D-printed models of the oral cavity for ram suspension-feeding fish, the angle of the backward-facing step with respect to the model's dorsal midline affected vortex parameters significantly, including rotational, tangential, and axial speed. These vortices were comparable to those quantified downstream of the backward-facing steps that were formed by the branchial arches of preserved American paddlefish in a recirculating flow tank. Our data indicate that vortices in cross-step filtration have the characteristics of forced vortices, as the flow of water inside the oral cavity provides the external torque required to sustain forced vortices. Additionally, we quantified a new variable for ram suspension feeding termed the fluid exit ratio. This is defined as the ratio of the total open pore area for water leaving the oral cavity via spaces between branchial arches that are not blocked by gill rakers, divided by the total area for water entering through the gape during ram suspension feeding. Our experiments demonstrated that the fluid exit ratio in preserved paddlefish was a significant predictor of the flow speeds that were quantified anterior of the rostrum, at the gape, directly dorsal of the first ceratobranchial, and in the forced vortex generated by the first ceratobranchial. Physical modeling of vortical cross-step filtration offers future opportunities to explore the complex interactions between structural features of the oral cavity, vortex parameters, motile particle behavior, and particle morphology that determine the suspension, concentration, and transport of particles within the oral cavity of ram suspension-feeding fish.http://europepmc.org/articles/PMC5862459?pdf=render
spellingShingle Hannah Brooks
Grant E Haines
M Carly Lin
S Laurie Sanderson
Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.
PLoS ONE
title Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.
title_full Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.
title_fullStr Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.
title_full_unstemmed Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.
title_short Physical modeling of vortical cross-step flow in the American paddlefish, Polyodon spathula.
title_sort physical modeling of vortical cross step flow in the american paddlefish polyodon spathula
url http://europepmc.org/articles/PMC5862459?pdf=render
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