Turbulence modulation by dense suspensions in channel flows

Francesco Picano, P. Simões Costa, Wim Paul Breugem, Luca Brandt

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

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Abstract

Dense suspensions are usually investigated in the laminar limit where inertial effects are insignificant. In this regime, the main effect of the suspended phase is to alter the rheological behavior of the flow which always displays higher effective viscosity with respect to the carrier fluid. When the flow rate is high enough, i.e. at high Reynolds number, the flow may become turbulent and the interaction between solid and liquid phase modifies the turbulent dynamics that we know in single-phase fluids. In the present work, we study turbulent channel flows laden with finite-size particles at high volume fraction (F = 0:2) by means of Direct Numerical Simulations. A direct-forcing Immersed Boundary Method has been adopted to couple liquid and solid phases. The two-phase simulations have been performed fixing the bulk Reynolds number at Reb = Ub 2h=n = 12000 (Ub bulk velocity, h channel half-width and n the fluid kinematic viscosity). The particle size is relatively large with respect to the viscous length, i.e. 10 and 20 times, but smaller than large scales. We will present a detailed comparison of the statistical behavior of the particle-laden flow and the corresponding single-phase flow. The presence of the solid phase strongly alters the wall turbulence dynamics and its effect cannot be accounted only considering the higher rheological effective viscosity.

Original languageEnglish
Title of host publicationProceedings 10th International Symposium on Turbulence and Shear Flow Phenomena (TSFP10)
Place of PublicationChigago, IL, USA
PublisherTSFP
Number of pages6
Volume1
Publication statusPublished - 2017
Event10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017 - Chicago, United States
Duration: 6 Jul 20179 Jul 2017
Conference number: 10
http://tsfp10.org/

Conference

Conference10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017
Abbreviated titleTSFP 2017
CountryUnited States
CityChicago
Period6/07/179/07/17
Internet address

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