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Dispersion of swimm...
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Croze, Ottavio A.
(författare)
Dispersion of swimming algae in laminar and turbulent channel flows : consequences for photobioreactors
- Artikel/kapitelEngelska2013
Förlag, utgivningsår, omfång ...
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2013-04-06
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The Royal Society,2013
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printrdacarrier
Nummerbeteckningar
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LIBRIS-ID:oai:DiVA.org:kth-119718
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https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-119718URI
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https://doi.org/10.1098/rsif.2012.1041DOI
Kompletterande språkuppgifter
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Språk:engelska
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Sammanfattning på:engelska
Ingår i deldatabas
Klassifikation
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Ämneskategori:ref swepub-contenttype
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Ämneskategori:art swepub-publicationtype
Anmärkningar
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QC 20130325
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Shear flow significantly affects the transport of swimming algae in suspension. For example, viscous and gravitational torques bias bottom-heavy cells to swim towards regions of downwelling fluid (gyrotaxis). It is necessary to understand how such biases affect algal dispersion in natural and industrial flows, especially in view of growing interest in algal photobioreactors. Motivated by this, we here study the dispersion of gyrotactic algae in laminar and turbulent channel flows using direct numerical simulation (DNS) and a previously published analytical swimming dispersion theory. Time-resolved dispersion measures are evaluated as functions of the Peclet and Reynolds numbers in upwelling and downwelling flows. For laminar flows, DNS results are compared with theory using competing descriptions of biased swimming cells in shear flow. Excellent agreement is found for predictions that employ generalized Taylor dispersion. The results highlight peculiarities of gyrotactic swimmer dispersion relative to passive tracers. In laminar downwelling flow the cell distribution drifts in excess of the mean flow, increasing in magnitude with Peclet number. The cell effective axial diffusivity increases and decreases with Peclet number (for tracers it merely increases). In turbulent flows, gyrotactic effects are weaker, but discernable and manifested as non-zero drift. These results should have a significant impact on photobioreactor design.
Ämnesord och genrebeteckningar
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algae
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swimming micro-organisms
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Taylor dispersion
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direct numerical simulation
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turbulent transport
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photobioreactors
Biuppslag (personer, institutioner, konferenser, titlar ...)
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Sardina, GaetanoKTH,Mekanik,Linné Flow Center, FLOW,Swedish E-Science Research Center (SeRC)(Swepub:kth)u1ckm9ek
(författare)
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Ahmed, MansoorKTH,Mekanik,Linné Flow Center, FLOW,Swedish E-Science Research Center (SeRC)(Swepub:kth)u1mkjp0f
(författare)
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Bees, Martin A.
(författare)
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Brandt, LucaKTH,Mekanik,Linné Flow Center, FLOW,Swedish E-Science Research Center (SeRC)(Swepub:kth)u15iawoo
(författare)
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KTHMekanik
(creator_code:org_t)
Sammanhörande titlar
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Ingår i:Journal of the Royal Society Interface: The Royal Society10:81, s. 20121041-1742-56891742-5662
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