Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-28T17:53:44.588Z Has data issue: false hasContentIssue false
  • English
  • Français

Disks settling in turbulence

Published online by Cambridge University Press:  02 December 2019

L. B. Esteban Open the ORCID record for L. B. Esteban [Opens in a new window] ,
J. S. Shrimpton  and
B. Ganapathisubramani
L. B. Esteban*
Affiliation:
Aerodynamics and Flight Mechanics Group, University of Southampton, University Rd, SouthamptonSO17 1BJ, UK
J. S. Shrimpton
Affiliation:
Aerodynamics and Flight Mechanics Group, University of Southampton, University Rd, SouthamptonSO17 1BJ, UK
B. Ganapathisubramani
Affiliation:
Aerodynamics and Flight Mechanics Group, University of Southampton, University Rd, SouthamptonSO17 1BJ, UK
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

This paper describes an experimental investigation of the dynamics of freely falling thin circular disks settling through turbulence. The patterns of the three-dimensional disk motion are studied using an orthogonal arrangement of two high speed cameras. Turbulence is generated in a water tank using a random jet array facility where the jets are mounted in a co-planar configuration. The facility is run continuously until turbulence reaches a statistically stationary state, then, all water pumps are turned off simultaneously and a disk is released after a given waiting time. Contrary to spherical particles, finite-size inertial disks show an increase in the descent velocity for turbulence velocity fluctuations smaller than the particle descent velocity in quiescent flow. Thus, we observe a severe increase of the mean descent velocity of the disk with increasing magnitude of the turbulence velocity fluctuations (up to $20\,\%$ of the velocity in quiescent flow for the disk with higher dimensionless inertia $I^{\ast }$). We also observe descent events that do not exist for disks falling in still fluid; i.e. ‘slow tumbling’ events and ‘levitating’ events. Finally, we show that the dominant frequency of the particle oscillatory motion decreases for increasing descent velocity and that particles exhibit oscillatory frequencies that never exceed the dominant frequency in quiescent flow by more than $30\,\%$.

JFM classification

Turbulent Flows: Homogeneous turbulence Multiphase and Particle-laden Flows: Multiphase flow
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 883 , 25 January 2020 , A58
Copyright
© 2019 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aliseda, A., Cartellier, A., Hainaux, F. & Lasheras, J. C. 2002 Effect of preferential concentration on the settling velocity of heavy particles in homogeneous isotropic turbulence. J. Fluid Mech. 468, 77–105.CrossRefGoogle Scholar
Anand, P., Ray, S. S. & Subramanian, G.2019 Orientation dynamics of sedimenting anisotropic particles in turbulence. arXiv:1907.02857.Google Scholar
Andersen, A., Pesavento, U. & Wang, Z. J. 2005a Analysis of transitions between fluttering, tumbling and steady descent of falling cards. J. Fluid Mech. 541, 91–104.CrossRefGoogle Scholar
Andersen, A., Pesavento, U. & Wang, Z. J. 2005b Unsteady aerodynamics of fluttering and tumbling plates. J. Fluid Mech. 541, 65–90.CrossRefGoogle Scholar
Auguste, F., Magnaudet, J. & Fabre, D. 2013 Falling styles of disks. J. Fluid Mech. 719, 388–405.CrossRefGoogle Scholar
Bec, J., Homann, H. & Ray, S. S. 2014 Gravity-driven enhancement of heavy particle clustering in turbulent flow. Phys. Rev. Lett. 112, 184501.CrossRefGoogle ScholarPubMed
Bellani, G. & Variano, E. A. 2013 Homogeneity and isotropy in a laboratory turbulent flow. Exp. Fluids 55, 1646–1666.CrossRefGoogle Scholar
Belmonte, A., Eisenberg, H. & Moses, E. 1998 From flutter to tumble: intertial drag and froude similarity in falling paper. Phys. Rev. Lett. 81, 345–348.CrossRefGoogle Scholar
Byron, M., Einarsson, J., Gustavsson, K., Voth, G., Mehlig, B. & Variano, E. 2015 Shape-dependence of particle rotation in isotropic turbulence. Phys. Fluids 27, 035101.CrossRefGoogle Scholar
Carter, D., Petersen, A., Amili, O. & Coletti, F. 2016 Generating and controlling homogeneous air turbulence using random jet arrays. Exp. Fluids 57, 189.CrossRefGoogle Scholar
Churst, M., Bouchet, G. & Dusek, J. 2013 Numerical simulation of the dynamics of freely falling discs. Phys. Fluids 25, 044102.Google Scholar
Esteban, L. B., Shrimpton, J. & Ganapathisubramani, B. 2019a Laboratory experiments on the temporal decay of homogeneous anisotropic turbulence. J. Fluid Mech. 862, 99–127.CrossRefGoogle Scholar
Esteban, L. B., Shrimpton, J. S. & Ganapathisubramani, B. 2018 Edge effects on the fluttering characteristics of freely falling planar particles. Phys. Rev. Fluids 3, 064302.Google Scholar
Esteban, L. B., Shrimpton, J. S. & Ganapathisubramani, B. 2019b Study of the circularity effect on drag of disk-like particles. Intl J. Multiphase Flow 110, 189–197.CrossRefGoogle Scholar
Field, S. B., Klaus, M., Moore, M. G. & Nori, F. 1977 Chaotic dynamics of falling disks. Nature 388, 252–254.CrossRefGoogle Scholar
Fornari, W., Picano, F. & Brandt, L. 2016 Sedimentation of finite-size spheres in quiescent and turbulent environments. J. Fluid Mech. 788, 640–669.CrossRefGoogle Scholar
Good, G. H., Gerashchenko, S. & Warhaft, Z. 2012 Intermittency and inertial particle entrainment at a turbulent interface: the effect of the large-scale eddies. J. Fluid Mech. 694, 371–398.CrossRefGoogle Scholar
Good, G.H., Ireland, P.J., Bewley, G.P., Bodenschatz, E., Collins, L.R. & Warhaft, Z. 2014 Settling regimes of inertial particles in isotropic turbulence. J. Fluid Mech. 759, R3.CrossRefGoogle Scholar
Gustavsson, K., Sheikh, M. Z., Lopez, D., Naso, A., Pumir, A. & Mehlig, B.2019 Theory for the effect of fluid inertia on the orientation of a small particle settling in turbulence. arXiv:1904.00481.CrossRefGoogle Scholar
Heisinger, L., Newton, P. & Kanso, E. 2014 Coins falling in water. J. Fluid Mech. 714, 243–253.CrossRefGoogle Scholar
Ho, H. W.1964 Fall velocity of a sphere in an oscillating fluid. PhD Thesis, University of Iowa, Iowa City, IA.Google Scholar
Ireland, P. J. & Collins, L. R. 2012 Direct numerical simulation of inertial particle entrainment in a shearless mixing layer. J. Fluid Mech. 704, 301–332.CrossRefGoogle Scholar
Jayaweera, K. O. L. F. 1972 An equivalent disc for calculating the terminal velocities of plate-like ice crystals. J. Atmos. Sci. 29, 596–597.2.0.CO;2>CrossRefGoogle Scholar
Jayaweera, K. O. L. F. & Mason, B. J. 1965 The behaviour of freely falling cylinders and cones in a viscous fluid. J. Fluid Mech. 22, 709–720.CrossRefGoogle Scholar
Kawanisi, K. & Shiozaki, R. 2008 Turbulent effects on the settling velocity of suspended sediment. J. Hydraul. Engng 2, 261–266.CrossRefGoogle Scholar
Lee, C., Su, Z., Zhong, H., Chen, S., Zhou, M. & Wu., J. 2013 Experimental investigation of freely falling thin disks. Part 2. Transition of three-dimensional motion from zigzag to spiral. J. Fluid Mech. 732, 77–104.CrossRefGoogle Scholar
Mallier, R. & Maxey, M. 1991 The settling of nonspherical particles in a cellular flow field. Phys. Fluids A 3, 1481–1494.CrossRefGoogle Scholar
Maxey, M. R. 1987 The gravitational settling of aerosol particle in homogeneous turbulence and random flow fields. J. Fluid Mech. 174, 441–465.CrossRefGoogle Scholar
Maxey, M. R. & Corrsin, S. 1986 Gravitational settling of aerosol particles in randomly oriented cellular flow fields. J. Atmos. Sci. 43, 1112–1134.2.0.CO;2>CrossRefGoogle Scholar
Murray, S. P. 1970 Settling velocities and vertical diffusion of particles in turbulent water. J. Geophys. Res. 75 (9), 1647–1654.CrossRefGoogle Scholar
Nielsen, P. 1984 On the motion of suspended particles. J. Geophys. Res. 89, 616–626.CrossRefGoogle Scholar
Nielsen, P. 1992 Coastal Bottom Boundary Layers and Sediment Transport. World Scientific.CrossRefGoogle Scholar
Nielsen, P. 1993 Turbulence effects on the settling of suspended particles. J. Sedim. Res. 63 (5), 835–838.Google Scholar
Reeks, M. W. 1977 On the dispersion of small particles suspended in an isotropic turbulent fluid. J. Fluid Mech. 83, 529–546.CrossRefGoogle Scholar
Rosa, B., Parishani, H., Ayala, O. & Wang, L. P. 2016 Settling velocity of small inertial particles in homogeneous isotropic turbulence from high-resolution DNS. Intl J. Multiphase Flow 83, 217–231.CrossRefGoogle Scholar
Siewert, C., Kunnen, R. P. J., Meinke, M. & Schroder, W. 2014 Orientation statistics and settling velocity of ellipsoids in decaying turbulence. Atmos. Res. 142, 45–56.CrossRefGoogle Scholar
Squires, K. D. & Eaton, J. K. 1991 Preferential concentration of particles by turbulence. Phys. Fluids 3, 1169–1178.CrossRefGoogle Scholar
Tom, J. & Bragg, A. 2019 Multiscale preferential sweeping of particles settling in turbulence. J. Fluid Mech. 871, 244–270.CrossRefGoogle Scholar
Variano, E. A. & Cowen, E. A. 2008 A random-jet-stirred turbulence tank. J. Fluid Mech. 604, 1–32.CrossRefGoogle Scholar
Voth, G. A. & Soldati, A. 2017 Anisotropic particles in turbulence. Annu. Rev. Fluid Mech. 49, 249–276.CrossRefGoogle Scholar
Wang, L. P. & Maxey, M. R. 1993 Settling velocity and concentration distribution of heavy particles in homogeneous isotropic turbulence. J. Fluid Mech. 256, 27–68.CrossRefGoogle Scholar
Willmarth, W. W., Hawk, N. E. & Harvey, R. L. 1964 Steady and unsteady motions and wakes of freely falling disks. Phys. Fluids 7, 197–208.CrossRefGoogle Scholar
Yang, C. Y. & Lei, U. 1998 The role of the turbulent scales in the settling velocity of heavy particles in homogeneous isotropic turbulence. J. Fluid Mech. 371, 179–205.CrossRefGoogle Scholar
Yang, T. S. & Shy, S. S. 2003 The settling velocity of heavy particles in an aqueous near-isotropic turbulence. Phys. Fluids 15 (4), 868–880.CrossRefGoogle Scholar
Yang, T. S. & Shy, S. S. 2005 Two-way interaction between solid particles and homogeneous air turbulence: particle settling rate and turbulence modification measurements. J. Fluid Mech. 526, 171–216.CrossRefGoogle Scholar
Zhong, H., Chen, S. & Lee, C. 2011 Experimental study of freely falling thin disks: transition from planar zigzag to spiral. Phys. Fluids 23, 011702.CrossRefGoogle Scholar
Zhong, H., Lee, C., Su, Z., Chen, S., Zhou, M. & Wu., J. 2013 Experimental investigation of freely falling thin disks. Part 1. The flow structures and Reynolds number effects on the zigzag motion. J. Fluid Mech. 716, 228–250.CrossRefGoogle Scholar