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Dispersion of a gyrotactic micro-organism suspension in a vertical pipe: the buoyancy–flow coupling effect

Published online by Cambridge University Press:  05 May 2023

Bohan Wang
Affiliation:
Laboratory of Systems Ecology and Sustainability Science, College of Engineering, Peking University, Beijing 100871, PR China
Weiquan Jiang
Affiliation:
Macao Environmental Research Institute, Macau University of Science and Technology, Macao 999078, PR China
Guoqian Chen*
Affiliation:
Laboratory of Systems Ecology and Sustainability Science, College of Engineering, Peking University, Beijing 100871, PR China Macao Environmental Research Institute, Macau University of Science and Technology, Macao 999078, PR China
*
Email address for correspondence: gqchen@pku.edu.cn

Abstract

Understanding the transport of micro-organisms in pipes is crucial to many fundamental problems, such as bioconvection and biodiesel production. In this work, we investigate the velocity profile and dispersion of a suspension of negatively buoyant, gyrotactic micro-organisms in a vertical pipe. With an imposed flow rate, the non-uniform radial cell concentration typical of gyrotaxis distorts the simple Poiseuille flow through inhomogeneous buoyancy, which in turn affects the cell concentration distribution. By solving the fundamental Smoluchowski equation and the Navier–Stokes equation simultaneously, we account for this bidirectional buoyancy–flow coupling effect. Asymptotic dispersion coefficients, namely, drift velocity and dispersivity, are further calculated with the obtained radial velocity and cell concentration profiles, which are assumed to be steady, symmetric and axially invariant. Using the gyrotactic micro-organism Chlamydomonas augustae as an example, detailed results are given to illustrate the effect of buoyancy–flow coupling. In downwelling flows, the buoyancy–flow coupling effect intensifies with the Richardson number $Ri$ quantifying the mean cell concentration, but is strongest at a moderate flow strength. The buoyancy–flow coupling effect significantly enhances the velocity and cell concentration in the central region, as well as the drift velocity and dispersivity. In contrast, the buoyancy–flow coupling effect is comparatively limited in upwelling flows, due to the dominant influence of the no-slip boundary condition imposed at the wall. Comparisons with predictions of existing approximate models are also presented.

Type
JFM Papers
Copyright
© The Author(s), 2023. Published by Cambridge University Press

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References

Aris, R. 1956 On the dispersion of a solute in a fluid flowing through a tube. Proc. R. Soc. A 235 (1200), 6777.Google Scholar
Barry, M.T., Rusconi, R., Guasto, J.S. & Stocker, R. 2015 Shear-induced orientational dynamics and spatial heterogeneity in suspensions of motile phytoplankton. J. R. Soc. Interface 12 (112), 20150791.CrossRefGoogle ScholarPubMed
Bearon, R.N. 2003 An extension of generalized Taylor dispersion in unbounded homogeneous shear flows to run-and-tumble chemotactic bacteria. Phys. Fluids 15 (6), 15521563.CrossRefGoogle Scholar
Bearon, R.N., Bees, M.A. & Croze, O.A. 2012 Biased swimming cells do not disperse in pipes as tracers: a population model based on microscale behaviour. Phys. Fluids 24 (12), 121902.CrossRefGoogle Scholar
Bearon, R.N. & Hazel, A.L. 2015 The trapping in high-shear regions of slender bacteria undergoing chemotaxis in a channel. J. Fluid Mech. 771, R3.CrossRefGoogle Scholar
Bearon, R.N., Hazel, A.L. & Thorn, G.J. 2011 The spatial distribution of gyrotactic swimming micro-organisms in laminar flow fields. J. Fluid Mech. 680, 602635.CrossRefGoogle Scholar
Bees, M.A. 2020 Advances in bioconvection. Annu. Rev. Fluid Mech. 52 (1), 449476.CrossRefGoogle Scholar
Bees, M.A. & Croze, O.A. 2010 Dispersion of biased swimming micro-organisms in a fluid flowing through a tube. Proc. R. Soc. A 466 (2119), 20572077.CrossRefGoogle Scholar
Bees, M.A. & Hill, N.A. 1998 Linear bioconvection in a suspension of randomly swimming, gyrotactic micro-organisms. Phys. Fluids 10 (8), 18641881.CrossRefGoogle Scholar
Bees, M.A., Hill, N.A. & Pedley, T.J. 1998 Analytical approximations for the orientation distribution of small dipolar particles in steady shear flows. J. Math. Biol. 36 (3), 269298.CrossRefGoogle Scholar
Berke, A.P., Turner, L., Berg, H.C. & Lauga, E. 2008 Hydrodynamic attraction of swimming microorganisms by surfaces. Phys. Rev. Lett. 101 (3), 038102.CrossRefGoogle ScholarPubMed
Brenner, H. & Edwards, D.A. 1993 Macrotransport Processes. Butterworth-Heinemann.Google Scholar
Chen, S.B. & Jiang, L. 1999 Orientation distribution in a dilute suspension of fibers subject to simple shear flow. Phys. Fluids 11 (10), 28782890.CrossRefGoogle Scholar
Chisti, Y. 2007 Biodiesel from microalgae. Biotechnol. Adv. 25 (3), 294306.CrossRefGoogle ScholarPubMed
Croze, O.A., Bearon, R.N. & Bees, M.A. 2017 Gyrotactic swimmer dispersion in pipe flow: testing the theory. J. Fluid Mech. 816, 481506.CrossRefGoogle Scholar
Croze, O.A., Sardina, G., Ahmed, M., Bees, M.A. & Brandt, L. 2013 Dispersion of swimming algae in laminar and turbulent channel flows: consequences for photobioreactors. J. R. Soc. Interface 10 (81), 20121041.CrossRefGoogle ScholarPubMed
Denissenko, P. & Lukaschuk, S. 2007 Velocity profiles and discontinuities propagation in a pipe flow of suspension of motile microorganisms. Phys. Lett. A 362 (4), 298304.CrossRefGoogle Scholar
Ezhilan, B. & Saintillan, D. 2015 Transport of a dilute active suspension in pressure-driven channel flow. J. Fluid Mech. 777, 482522.CrossRefGoogle Scholar
Frankel, I. & Brenner, H. 1989 On the foundations of generalized Taylor dispersion theory. J. Fluid Mech. 204, 97119.CrossRefGoogle Scholar
Fung, L.S.-L. 2021 Modelling the transport and pattern formation of gyrotactic microswimmer suspensions. PhD thesis, Imperial College London.Google Scholar
Fung, L., Bearon, R.N. & Hwang, Y. 2020 Bifurcation and stability of downflowing gyrotactic micro-organism suspensions in a vertical pipe. J. Fluid Mech. 902, A26.CrossRefGoogle Scholar
Fung, L., Bearon, R.N. & Hwang, Y. 2022 A local approximation model for macroscale transport of biased active Brownian particles in a flowing suspension. J. Fluid Mech. 935, A24.CrossRefGoogle Scholar
Fung, L. & Hwang, Y. 2020 A sequence of transcritical bifurcations in a suspension of gyrotactic microswimmers in vertical pipe. J. Fluid Mech. 902, R2.CrossRefGoogle Scholar
Guan, M.Y., Zeng, L., Jiang, W.Q., Guo, X.L., Wang, P., Wu, Z., Li, Z. & Chen, G.Q. 2022 Effects of wind on transient dispersion of active particles in a free-surface wetland flow. Commun. Nonlinear Sci. Numer. Simul. 115, 106766.CrossRefGoogle Scholar
Haugerud, I.S., Linga, G. & Flekkøy, E.G. 2022 Solute dispersion in channels with periodic square boundary roughness. J. Fluid Mech. 944, A53.CrossRefGoogle Scholar
Hill, N.A. & Bees, M.A. 2002 Taylor dispersion of gyrotactic swimming micro-organisms in a linear flow. Phys. Fluids 14 (8), 25982605.CrossRefGoogle Scholar
Hwang, Y. & Pedley, T.J. 2014 a Bioconvection under uniform shear: linear stability analysis. J. Fluid Mech. 738, 522562.CrossRefGoogle Scholar
Hwang, Y. & Pedley, T.J. 2014 b Stability of downflowing gyrotactic microorganism suspensions in a two-dimensional vertical channel. J. Fluid Mech. 749, 750777.CrossRefGoogle Scholar
Ishikawa, T. & Pedley, T.J. 2007 Diffusion of swimming model micro-organisms in a semi-dilute suspension. J. Fluid Mech. 588, 437462.CrossRefGoogle Scholar
Jiang, W. & Chen, G. 2019 Dispersion of active particles in confined unidirectional flows. J. Fluid Mech. 877, 134.CrossRefGoogle Scholar
Jiang, W. & Chen, G. 2020 Dispersion of gyrotactic micro-organisms in pipe flows. J. Fluid Mech. 889, A18.CrossRefGoogle Scholar
Jiang, W. & Chen, G. 2021 Transient dispersion process of active particles. J. Fluid Mech. 927, A11.CrossRefGoogle Scholar
Jiang, W., Zeng, L., Fu, X. & Wu, Z. 2022 Analytical solutions for reactive shear dispersion with boundary adsorption and desorption. J. Fluid Mech. 947, A37.CrossRefGoogle Scholar
Kessler, J.O. 1984 Gyrotactic buoyant convection and spontaneous pattern formation in algal cell cultures. In Nonequilibrium Cooperative Phenomena in Physics and Related Fields, pp. 241–248. Springer.CrossRefGoogle Scholar
Kessler, J.O. 1985 a Co-operative and concentrative phenomena of swimming micro-organisms. Contemp. Phys. 26 (2), 147166.CrossRefGoogle Scholar
Kessler, J.O. 1985 b Hydrodynamic focusing of motile algal cells. Nature (London) 313 (5999), 218220.CrossRefGoogle Scholar
Kessler, J.O. 1986 Individual and collective fluid dynamics of swimming cells. J. Fluid Mech. 173, 191205.CrossRefGoogle Scholar
Li, G. & Tang, J.X. 2009 Accumulation of microswimmers near a surface mediated by collision and rotational Brownian motion. Phys. Rev. Lett. 103 (7), 078101.CrossRefGoogle Scholar
Manela, A. & Frankel, I. 2003 Generalized Taylor dispersion in suspensions of gyrotactic swimming micro-organisms. J. Fluid Mech. 490, 99127.CrossRefGoogle Scholar
Maretvadakethope, S., Keaveny, E.E. & Hwang, Y. 2019 The instability of gyrotactically trapped cell layers. J. Fluid Mech. 868, R5.CrossRefGoogle Scholar
Omori, T., Kikuchi, K., Schmitz, M., Pavlovic, M., Chuang, C.-H. & Ishikawa, T. 2022 Rheotaxis and migration of an unsteady microswimmer. J. Fluid Mech. 930, A30.CrossRefGoogle Scholar
Pedley, T.J. 2010 Instability of uniform micro-organism suspensions revisited. J. Fluid Mech. 647, 335359.CrossRefGoogle Scholar
Pedley, T.J. & Kessler, J.O. 1990 A new continuum model for suspensions of gyrotactic micro-organisms. J. Fluid Mech. 212, 155182.CrossRefGoogle ScholarPubMed
Pedley, T.J. & Kessler, J.O. 1992 Hydrodynamic phenomena in suspensions of swimming microorganisms. Annu. Rev. Fluid Mech. 24 (1), 313358.CrossRefGoogle Scholar
Peng, Z. & Brady, J.F. 2020 Upstream swimming and Taylor dispersion of active Brownian particles. Phys. Rev. Fluids 5 (7), 073102.CrossRefGoogle Scholar
Rusconi, R., Guasto, J.S. & Stocker, R. 2014 Bacterial transport suppressed by fluid shear. Nat. Phys. 10 (3), 212217.CrossRefGoogle Scholar
Saintillan, D. 2014 Swimming in shear. J. Fluid Mech. 744, 14.CrossRefGoogle Scholar
Saintillan, D. 2018 Rheology of active fluids. Annu. Rev. Fluid Mech. 50 (1), 563592.CrossRefGoogle Scholar
Saintillan, D. & Shelley, M.J. 2008 a Instabilities and pattern formation in active particle suspensions: kinetic theory and continuum simulations. Phys. Rev. Lett. 100 (17), 178103.CrossRefGoogle ScholarPubMed
Saintillan, D. & Shelley, M.J. 2008 b Instabilities, pattern formation, and mixing in active suspensions. Phys. Fluids 20 (12), 123304.CrossRefGoogle Scholar
Taylor, G. 1953 Dispersion of soluble matter in solvent flowing slowly through a tube. Proc. R. Soc. A 219 (1137), 186203.Google Scholar
Thorn, G.J. & Bearon, R.N. 2010 Transport of spherical gyrotactic organisms in general three-dimensional flow fields. Phys. Fluids 22 (4), 041902.CrossRefGoogle Scholar
Vennamneni, L., Nambiar, S. & Subramanian, G. 2020 Shear-induced migration of microswimmers in pressure-driven channel flow. J. Fluid Mech. 890, A15.CrossRefGoogle Scholar
Walker, B.J., Ishimoto, K., Moreau, C., Gaffney, E.A. & Dalwadi, M.P. 2022 Emergent rheotaxis of shape-changing swimmers in Poiseuille flow. J. Fluid Mech. 944, R2.CrossRefGoogle Scholar
Wang, B., Jiang, W. & Chen, G. 2022 Gyrotactic trapping of micro-swimmers in simple shear flows: a study directly from the fundamental Smoluchowski equation. J. Fluid Mech. 939, A37.CrossRefGoogle Scholar
Zeng, L., Jiang, W. & Pedley, T.J. 2022 Sharp turns and gyrotaxis modulate surface accumulation of microorganisms. Proc. Natl Acad. Sci. USA 119 (42), e2206738119.CrossRefGoogle ScholarPubMed
Zeng, L. & Pedley, T.J. 2018 Distribution of gyrotactic micro-organisms in complex three-dimensional flows. Part 1. Horizontal shear flow past a vertical circular cylinder. J. Fluid Mech. 852, 358397.CrossRefGoogle Scholar