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Interface-resolved ...
Interface-resolved simulations of small inertial particles in turbulent channel flow
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- Costa, Pedro (författare)
- KTH,Mekanik,Linné Flow Center, FLOW,SeRC - Swedish e-Science Research Centre,Univ Iceland, Fac Ind Engn Mech Engn & Comp Sci, Hjardarhagi 2-6, IS-107 Reykjavik, Iceland.
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- Brandt, Luca (författare)
- KTH,Mekanik,Linné Flow Center, FLOW,SeRC - Swedish e-Science Research Centre
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- Picano, Francesco (författare)
- Univ Padua, Dept Ind Engn, Via Venezia 1, I-35131 Padua, Italy.
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(creator_code:org_t)
- 2019-11-29
- 2020
- Engelska.
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Ingår i: Journal of Fluid Mechanics. - : Cambridge University Press. - 0022-1120 .- 1469-7645. ; 883
- Relaterad länk:
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https://www.cambridg...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- We present a direct comparison between interface-resolved and one-way-coupled point-particle direct numerical simulations (DNS) of gravity-free turbulent channel flow laden with small inertial particles, with high particle-to-fluid density ratio and diameter of approximately three viscous units. The most dilute flow considered, solid volume fraction O(10(-5)), shows the particle feedback on the flow to be negligible, whereas differences with respect to the unladen case, notably a drag increase of approximately 10 %, are found for a volume fraction O(10(-4)). This is attributed to a dense layer of particles at the wall, caused by turbophoresis, flowing with large particle-to-fluid apparent slip velocity. The most dilute case is therefore taken as the benchmark for assessing the validity of a widely used point-particle model, where the particle dynamics results only from inertial and nonlinear drag forces. In the bulk of the channel, the first- and second-order moments of the particle velocity from the point-particle DNS agree well with those from the interface-resolved DNS. Close to the wall, however, most of the statistics show major qualitative differences. We show that this difference originates from the strong shear-induced lift force acting on the particles in the near-wall region. This mechanism is well captured by the lift force model due to Saffman (J. Fluid Mech., vol. 22 (2), 1965, pp. 385-400), while other widely used, more elaborate, approaches aiming at extending the lift model for a wider range of particle Reynolds numbers can actually underpredict the magnitude of the near-wall particle velocity fluctuations for the cases analysed here.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Maskinteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Mechanical Engineering (hsv//eng)
Nyckelord
- multiphase flow
- particle
- fluid flows
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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