1
|
Bhowmick T, Seesing J, Gustavsson K, Guettler J, Wang Y, Pumir A, Mehlig B, Bagheri G. Inertia Induces Strong Orientation Fluctuations of Nonspherical Atmospheric Particles. PHYSICAL REVIEW LETTERS 2024; 132:034101. [PMID: 38307048 DOI: 10.1103/physrevlett.132.034101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/28/2023] [Accepted: 11/22/2023] [Indexed: 02/04/2024]
Abstract
The orientation of nonspherical particles in the atmosphere, such as volcanic ash and ice crystals, influences their residence times and the radiative properties of the atmosphere. Here, we demonstrate experimentally that the orientation of heavy submillimeter spheroids settling in still air exhibits decaying oscillations, whereas it relaxes monotonically in liquids. Theoretical analysis shows that these oscillations are due to particle inertia, caused by the large particle-fluid mass-density ratio. This effect must be accounted for to model solid particles in the atmosphere.
Collapse
Affiliation(s)
- T Bhowmick
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077 Germany
- Institute for the Dynamics of Complex Systems, University of Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077 Germany
| | - J Seesing
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077 Germany
| | - K Gustavsson
- Department of Physics, Gothenburg University, Gothenburg, SE-40530 Sweden
| | - J Guettler
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077 Germany
| | - Y Wang
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077 Germany
| | - A Pumir
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077 Germany
- Laboratoire de Physique, ENS de Lyon, Université de Lyon 1 and CNRS, Lyon, F-69007 France
| | - B Mehlig
- Department of Physics, Gothenburg University, Gothenburg, SE-40530 Sweden
| | - G Bagheri
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077 Germany
| |
Collapse
|
2
|
Nath AVS, Roy A, Govindarajan R, Ravichandran S. Transport of condensing droplets in Taylor-Green vortex flow in the presence of thermal noise. Phys Rev E 2022; 105:035101. [PMID: 35428137 DOI: 10.1103/physreve.105.035101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
We study the role of phase change and thermal noise in particle transport in turbulent flows. We employ a toy model to extract the main physics: Condensing droplets are modelled as heavy particles which grow in size, the ambient flow is modelled as a two-dimensional Taylor-Green flow consisting of an array of vortices delineated by separatrices, and thermal noise are modelled as uncorrelated Gaussian white noise. In general, heavy inertial particles are centrifuged out of regions of high vorticity and into regions of high strain. In cellular flows, we find, in agreement with earlier results, that droplets with Stokes numbers smaller than a critical value, St<St_{cr}, remain trapped in the vortices in which they are initialized, while larger droplets move ballistically away from their initial positions by crossing separatrices. We independently vary the Péclet number Pe characterizing the amplitude of thermal noise and the condensation rate Π to study their effects on the critical Stokes number for droplet trapping, as well as on the final states of motion of the droplets. We find that the imposition of thermal noise, or of a finite condensation rate, allows droplets of St<St_{cr} to leave their initial vortices. We find that the effects of thermal noise become negligible for growing droplets and that growing droplets achieve ballistic motion when their Stokes numbers become O(1). We also find an intermediate regime prior to attaining the ballistic state, in which droplets move diffusively away from their initial vortices in the presence of thermal noise.
Collapse
Affiliation(s)
- Anu V S Nath
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Anubhab Roy
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Rama Govindarajan
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560089, India
| | - S Ravichandran
- Nordita, KTH Royal Institute of Technology and Stockholm University, SE-10691 Stockholm, Sweden
| |
Collapse
|
3
|
CFD-DEM simulation of particle revolution and high-speed self-rotation in cyclones with different structural and operating parameters. CHEMICAL ENGINEERING JOURNAL ADVANCES 2021. [DOI: 10.1016/j.ceja.2021.100176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
4
|
Roy A, Gupta A, Ray SS. Inertial spheroids in homogeneous, isotropic turbulence. Phys Rev E 2018; 98:021101. [PMID: 30253548 DOI: 10.1103/physreve.98.021101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Indexed: 11/07/2022]
Abstract
We study the rotational dynamics of inertial disks and rods in three-dimensional, homogeneous, isotropic turbulence. In particular, we show how the alignment and the decorrelation timescales of such spheroids depend, critically, on both the level of inertia and the aspect ratio of these particles. These results illustrate the effect of inertia-which leads to a preferential sampling of the local flow geometry-on the statistics of both disks and rods in a turbulent flow. Our results are important for a variety of natural and industrial settings where the turbulent transport of asymmetric, spheroidal inertial particles is ubiquitous.
Collapse
Affiliation(s)
- Amal Roy
- Department of Mathematics, Indian Institute of Science, Bangalore 560012, India.,International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore 560089, India
| | - Anupam Gupta
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Samriddhi Sankar Ray
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore 560089, India
| |
Collapse
|
5
|
Henry C, Krstulovic G, Bec J. Tumbling dynamics of inertial inextensible chains in extensional flow. Phys Rev E 2018; 98:023107. [PMID: 30253530 DOI: 10.1103/physreve.98.023107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Indexed: 06/08/2023]
Abstract
This paper investigates the effect of inertia on the dynamics of elongated chains to go beyond the overdamped case that is often used to study such systems. For that purpose, numerical simulations are performed considering the motion of freely jointed bead-rod chains in an extensional flow in the presence of thermal noise. The coil-stretch transition and the tumbling instability are characterized as a function of three parameters: the Péclet number, the Stokes number, and the chain length. Numerical results show that the coil-stretch transition remains when inertia is present and that it depends nonlinearly on the Stokes and Péclet numbers. Theoretical and numerical analyses also highlight the role of intermediate stable configurations in the dynamics of elongated chains: chains can indeed remain trapped for a certain time in these configurations, especially while undergoing a tumbling event.
Collapse
Affiliation(s)
- Christophe Henry
- Université Côte d'Azur, CNRS, OCA, Laboratoire Lagrange, Bd. de l'Observatoire, Nice, France
| | - Giorgio Krstulovic
- Université Côte d'Azur, CNRS, OCA, Laboratoire Lagrange, Bd. de l'Observatoire, Nice, France
| | - Jérémie Bec
- Université Côte d'Azur, CNRS, OCA, Laboratoire Lagrange, Bd. de l'Observatoire, Nice, France
| |
Collapse
|
6
|
Gustavsson K, Jucha J, Naso A, Lévêque E, Pumir A, Mehlig B. Statistical Model for the Orientation of Nonspherical Particles Settling in Turbulence. PHYSICAL REVIEW LETTERS 2017; 119:254501. [PMID: 29303314 DOI: 10.1103/physrevlett.119.254501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Indexed: 06/07/2023]
Abstract
The orientation of small anisotropic particles settling in a turbulent fluid determines some essential properties of the suspension. We show that the orientation distribution of small heavy spheroids settling through turbulence can be accurately predicted by a simple Gaussian statistical model that takes into account particle inertia and provides a quantitative understanding of the orientation distribution on the problem parameters when fluid inertia is negligible. Our results open the way to a parametrization of the distribution of ice crystals in clouds, and potentially lead to an improved understanding of radiation reflection or particle aggregation through collisions in clouds.
Collapse
Affiliation(s)
- K Gustavsson
- Department of Physics, Gothenburg University, 41296 Gothenburg, Sweden
| | - J Jucha
- Laboratoire de Physique, Ecole Normale Supérieure de Lyon and CNRS, F-69007 Lyon, France
- Projektträger Jülich, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - A Naso
- LMFA, Ecole Centrale de Lyon and CNRS, F-69134 Ecully, France
| | - E Lévêque
- LMFA, Ecole Centrale de Lyon and CNRS, F-69134 Ecully, France
| | - A Pumir
- Laboratoire de Physique, Ecole Normale Supérieure de Lyon and CNRS, F-69007 Lyon, France
| | - B Mehlig
- Department of Physics, Gothenburg University, 41296 Gothenburg, Sweden
| |
Collapse
|
7
|
Plan ELCVM, Musacchio S, Vincenzi D. Emergence of chaos in a viscous solution of rods. Phys Rev E 2017; 96:053108. [PMID: 29347655 DOI: 10.1103/physreve.96.053108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Indexed: 06/07/2023]
Abstract
It is shown that the addition of small amounts of microscopic rods in a viscous fluid at low Reynolds number causes a significant increase of the flow resistance. Numerical simulations of the dynamics of the solution reveal that this phenomenon is associated to a transition from laminar to chaotic flow. Polymer stresses give rise to flow instabilities which, in turn, perturb the alignment of the rods. This coupled dynamics results in the activation of a wide range of scales, which enhances the mixing efficiency of viscous flows.
Collapse
|
8
|
Candelier F, Einarsson J, Mehlig B. Angular Dynamics of a Small Particle in Turbulence. PHYSICAL REVIEW LETTERS 2016; 117:204501. [PMID: 27886512 DOI: 10.1103/physrevlett.117.204501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Indexed: 06/06/2023]
Abstract
We compute the angular dynamics of a neutrally buoyant nearly spherical particle immersed in an unsteady fluid. We assume that the particle is small, that its translational slip velocity is negligible, and that unsteady and convective inertia are small perturbations. We derive an approximation for the torque on the particle that determines the first inertial corrections to Jeffery's equation. These corrections arise as a consequence of local vortex stretching and can be substantial in turbulence, where local vortex stretching is strong and closely linked to the irreversibility of turbulence.
Collapse
Affiliation(s)
- F Candelier
- Aix-Marseille University-IUSTI (UMR CNRS 7343), 13 453 Marseille Cedex, France
| | - J Einarsson
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
| | - B Mehlig
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
| |
Collapse
|
9
|
Kramel S, Voth GA, Tympel S, Toschi F. Preferential Rotation of Chiral Dipoles in Isotropic Turbulence. PHYSICAL REVIEW LETTERS 2016; 117:154501. [PMID: 27768367 DOI: 10.1103/physrevlett.117.154501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Indexed: 06/06/2023]
Abstract
We introduce a new particle shape which shows preferential rotation in three dimensional homogeneous isotropic turbulence. We call these particles chiral dipoles because they consist of a rod with two helices of opposite handedness, one at each end. 3D printing is used to fabricate these particles with a length in the inertial range and their rotations are tracked in a turbulent flow between oscillating grids. High aspect ratio chiral dipoles preferentially align with their long axis along the extensional eigenvectors of the strain rate tensor, and the helical ends respond to the extensional strain rate with a mean spinning rate that is nonzero. We use Stokesian dynamics simulations of chiral dipoles in pure strain flow to quantify the dependence of spinning on particle shape. Based on the known response to pure strain, we build a model that gives the spinning rate of small chiral dipoles using velocity gradients along Lagrangian trajectories from high resolution direct numerical simulations. The statistics of chiral dipole spinning determined with this model show surprisingly good agreement with the measured spinning of much larger chiral dipoles in the experiments.
Collapse
Affiliation(s)
- Stefan Kramel
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
| | - Greg A Voth
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
| | - Saskia Tympel
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, Netherlands
| | - Federico Toschi
- Department of Applied Physics and Department of Mathematics and Computer Science, Eindhoven University of Technology, 5600 MB, Eindhoven, Netherlands and Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche, Via dei Taurini 19, 00185 Rome, Italy
| |
Collapse
|
10
|
|
11
|
Gustavsson K, Berglund F, Jonsson PR, Mehlig B. Preferential Sampling and Small-Scale Clustering of Gyrotactic Microswimmers in Turbulence. PHYSICAL REVIEW LETTERS 2016; 116:108104. [PMID: 27015512 DOI: 10.1103/physrevlett.116.108104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Indexed: 06/05/2023]
Abstract
Recent studies show that spherical motile microorganisms in turbulence subject to gravitational torques gather in down-welling regions of the turbulent flow. By analyzing a statistical model we analytically compute how shape affects the dynamics, preferential sampling, and small-scale spatial clustering. We find that oblong organisms may spend more time in up-welling regions of the flow, and that all organisms are biased to regions of positive fluid-velocity gradients in the upward direction. We analyze small-scale spatial clustering and find that oblong particles may either cluster more or less than spherical ones, depending on the strength of the gravitational torques.
Collapse
Affiliation(s)
- K Gustavsson
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
- Department of Physics and INFN, University of Rome 'Tor Vergata', 00133 Rome, Italy
| | - F Berglund
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
| | - P R Jonsson
- Department of Biological and Environmental Sciences-Tjärnö, SE-45296 Strömstad, Sweden
| | - B Mehlig
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
| |
Collapse
|
12
|
Zhao L, Challabotla NR, Andersson HI, Variano EA. Rotation of Nonspherical Particles in Turbulent Channel Flow. PHYSICAL REVIEW LETTERS 2015; 115:244501. [PMID: 26705637 DOI: 10.1103/physrevlett.115.244501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Indexed: 06/05/2023]
Abstract
The effects of particle inertia, particle shape, and fluid shear on particle rotation are examined using direct numerical simulation of turbulent channel flow. Particles at the channel center (nearly isotropic turbulence) and near the wall (highly sheared flow) show different rotation patterns and surprisingly different effects of particle inertia. Oblate particles at the center tend to rotate orthogonally to their symmetry axes, whereas prolate particles rotate around their symmetry axes. This trend is weakened by increasing inertia so that highly inertial oblate spheroids rotate nearly isotropically about their principle axes at the channel center. Near the walls, inertia does not move the rotation of spheroids towards isotropy but, rather, reverses the trend, causing oblate spheroids to rotate strongly about their symmetry axes and prolate spheroids to rotate normal to their symmetry axes. The observed phenomena are mostly ascribed to preferential orientations of the spheroids.
Collapse
Affiliation(s)
- Lihao Zhao
- Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Niranjan Reddy Challabotla
- Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Helge I Andersson
- Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Evan A Variano
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, USA
| |
Collapse
|
13
|
Rosén T, Einarsson J, Nordmark A, Aidun CK, Lundell F, Mehlig B. Numerical analysis of the angular motion of a neutrally buoyant spheroid in shear flow at small Reynolds numbers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:063022. [PMID: 26764819 DOI: 10.1103/physreve.92.063022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Indexed: 06/05/2023]
Abstract
We numerically analyze the rotation of a neutrally buoyant spheroid in a shear flow at small shear Reynolds number. Using direct numerical stability analysis of the coupled nonlinear particle-flow problem, we compute the linear stability of the log-rolling orbit at small shear Reynolds number Re(a). As Re(a)→0 and as the box size of the system tends to infinity, we find good agreement between the numerical results and earlier analytical predictions valid to linear order in Re(a) for the case of an unbounded shear. The numerical stability analysis indicates that there are substantial finite-size corrections to the analytical results obtained for the unbounded system. We also compare the analytical results to results of lattice Boltzmann simulations to analyze the stability of the tumbling orbit at shear Reynolds numbers of order unity. Theory for an unbounded system at infinitesimal shear Reynolds number predicts a bifurcation of the tumbling orbit at aspect ratio λ(c)≈0.137 below which tumbling is stable (as well as log rolling). The simulation results show a bifurcation line in the λ-Re(a) plane that reaches λ≈0.1275 at the smallest shear Reynolds number (Re(a)=1) at which we could simulate with the lattice Boltzmann code, in qualitative agreement with the analytical results.
Collapse
Affiliation(s)
- T Rosén
- KTH Mechanics, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
- Wallenberg Wood Science Center, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - J Einarsson
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
| | - A Nordmark
- KTH Mechanics, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - C K Aidun
- George W. Woodruff School of Mechanical Engineering and Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332-0405, USA
| | - F Lundell
- KTH Mechanics, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
- Wallenberg Wood Science Center, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - B Mehlig
- Department of Physics, Gothenburg University, SE-41296 Gothenburg, Sweden
| |
Collapse
|
14
|
Gupta A, Vincenzi D, Pandit R. Elliptical tracers in two-dimensional, homogeneous, isotropic fluid turbulence: the statistics of alignment, rotation, and nematic order. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:021001. [PMID: 25353409 DOI: 10.1103/physreve.89.021001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Indexed: 06/04/2023]
Abstract
We study the statistical properties of orientation and rotation dynamics of elliptical tracer particles in two-dimensional, homogeneous, and isotropic turbulence by direct numerical simulations. We consider both the cases in which the turbulent flow is generated by forcing at large and intermediate length scales. We show that the two cases are qualitatively different. For large-scale forcing, the spatial distribution of particle orientations forms large-scale structures, which are absent for intermediate-scale forcing. The alignment with the local directions of the flow is much weaker in the latter case than in the former. For intermediate-scale forcing, the statistics of rotation rates depends weakly on the Reynolds number and on the aspect ratio of particles. In contrast with what is observed in three-dimensional turbulence, in two dimensions the mean-square rotation rate increases as the aspect ratio increases.
Collapse
Affiliation(s)
- Anupam Gupta
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Dario Vincenzi
- Université Nice Sophia Antipolis, CNRS, Laboratoire J. A. Dieudonné, UMR 7351, 06100 Nice, France
| | - Rahul Pandit
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|