Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-21T16:55:59.843Z Has data issue: false hasContentIssue false

The effect of Reynolds number on the dynamics and wakes of freely rising and falling spheres

Published online by Cambridge University Press:  29 March 2010

M. HOROWITZ*
Affiliation:
144 Upson Hall, Cornell University, Ithaca, NY 14853, USA
C. H. K. WILLIAMSON
Affiliation:
144 Upson Hall, Cornell University, Ithaca, NY 14853, USA
*
Email address for correspondence: [email protected]

Abstract

In this paper, we study the effect of the Reynolds number (Re) on the dynamics and vortex formation modes of spheres rising or falling freely through a fluid (where Re = 100–15000). Since the oscillation of freely falling spheres was first reported by Newton (University of California Press, 3rd edn, 1726, translated in 1999), the fundamental question of whether a sphere will vibrate, as it rises or falls, has been the subject of a number of investigations, and it is clear that the mass ratio m* (defined as the relative density of the sphere compared to the fluid) is an important parameter to define when vibration occurs. Although all rising spheres (m* < 1) were previously found to oscillate, either chaotically or in a periodic zigzag motion or even to follow helical trajectories, there is no consensus regarding precise values of the mass ratio (m*crit) separating vibrating and rectilinear regimes. There is also a large scatter in measurements of sphere drag in both the vibrating and rectilinear regimes.

In our experiments, we employ spheres with 133 combinations of m* and Re, to provide a comprehensive study of the sphere dynamics and vortex wakes occurring over a wide range of Reynolds numbers. We find that falling spheres (m* > 1) always move without vibration. However, in contrast with previous studies, we discover that a whole regime of buoyant spheres rise through a fluid without vibration. It is only when one passes below a critical value of the mass ratio, that the sphere suddenly begins to vibrate periodically and vigorously in a zigzag trajectory within a vertical plane. The critical mass is nearly constant over two ranges of Reynolds number (m*crit ≈ 0.4 for Re = 260–1550 and m*crit ≈ 0.6 for Re > 1550). We do not observe helical or spiral trajectories, or indeed chaotic types of trajectory, unless the experiments are conducted in disturbed background fluid. The wakes for spheres moving rectilinearly are comparable with wakes of non-vibrating spheres. We find that these wakes comprise single-sided and double-sided periodic sequences of vortex rings, which we define as the ‘R’ and ‘2R’ modes. However, in the zigzag regime, we discover a new ‘4R’ mode, in which four vortex rings are created per cycle of oscillation. We find a number of changes to occur at a Reynolds number of 1550, and we suggest the possibility of a resonance between the shear layer instability and the vortex shedding (loop) instability. From this study, ensuring minimal background disturbances, we have been able to present a new regime map of dynamics and vortex wake modes as a function of the mass ratio and Reynolds number {m*, Re}, as well as a reasonable collapse of the drag measurements, as a function of Re, onto principally two curves, one for the vibrating regime and one for the rectilinear trajectories.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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

REFERENCES

Allen, H. S. 1900 The motion of a sphere in a viscous fluid: III. Phil. Mag. 50, 519534.Google Scholar
Bacon, D. L. & Reid, E. G. 1923 The resistance of spheres in wind tunnels and in air. Tech. Rep. No. 185. NACA.Google Scholar
Bloor, M. S. 1964 The transition to turbulence in the wake of a circular cylinder. J. Fluid Mech. 19, 290304.CrossRefGoogle Scholar
Boillat, J. L. & Graf, W. H. 1981 Settling velocity of spherical particles in calm water. J. Hydraul. Div. ASCE 107, 11231131.CrossRefGoogle Scholar
Bouchet, G., Mebarek, M. & Dušek, J. 2006 Hydrodynamic forces acting on a rigid fixed sphere in early transitional regimes. Eur. J. Mech. B 25, 321336.Google Scholar
Brücker, C. 1999 Structure and dynamics of the wake of bubbles and its relevance for bubble interaction. Phys. Fluids 11, 17811796.Google Scholar
Brücker, C. 2001 Spatio-temporal reconstruction of vortex dynamics in axisymmetric wakes. J. Fluids Struct. 15, 543554.CrossRefGoogle Scholar
Christiansen, E. B. & Barker, D. H. 1965 The effect of shape and density on the free settling of particles at high Reynolds numbers. AIChE J. 11, 145151.Google Scholar
Fabre, D., Auguste, F. & Magnaudet, J. 2008 Bifurcations and symmetry breaking in the wake of axisymmetric bodies. Phys. Fluids 20, 051702.Google Scholar
Fernandes, P. C., Risso, F., Ern, P. & Magnaudet, J. 2007 Oscillatory motion and wake instability of freely rising axisymmetric bodies. J. Fluid Mech. 573, 479502.CrossRefGoogle Scholar
Flemming, F. & Williamson, C. H. K. 2005 Vortex-induced vibrations of a pivoted cylinder. J. Fluid Mech. 522, 215252.Google Scholar
Goldburg, A. & Florsheim, B. H. 1966 Transition and Strouhal number for the incompressible wake of various bodies. Phys. Fluids 9, 4550.Google Scholar
Govardhan, R. & Williamson, C. H. K. 2000 Modes of vortex formation and frequency response of a freely vibrating cylinder. J. Fluid Mech. 420, 85130.Google Scholar
Govardhan, R. & Williamson, C. H. K. 2002 Resonance forever: existence of a critical mass and an infinite regime of resonance in vortex-induced vibration. J. Fluid Mech. 473, 147166.Google Scholar
Govardhan, R. N. & Williamson, C. H. K. 2005 Vortex-induced vibrations of a sphere. J. Fluid Mech. 531, 1147.CrossRefGoogle Scholar
Gumowski, K., Miedzik, J., Goujon-Durand, S., Jenffer, P. & Wesfried, J. E. 2008 Transition to a time-dependent state of fluid flow in the wake of a sphere. Phys. Rev. E 77, 055308.CrossRefGoogle ScholarPubMed
Hartman, M. & Yates, J. G. 1993 Free-fall of solid particles through fluids. Collect. Czech. Chem. Commun. 58, 961982.Google Scholar
Hirsch, P. 1923 Über die Bewegung von Kugeln in ruhenden Flüssigkeiten. Z. Angew. Math. Mech. 3, 93107.Google Scholar
Horowitz, M. & Williamson, C. H. K. 2006 Dynamics of a rising and falling cylinder. J. Fluids Struct. 22, 837843.Google Scholar
Horowitz, M. & Williamson, C. H. K. 2008 Critical mass and a new periodic four-ring vortex wake mode for freely rising and falling spheres. Phys. Fluids 20, 101701.Google Scholar
Horowitz, M. & Williamson, C. H. K. Vortex-induced vibration of a rising and falling cylinder. J. Fluid Mech. (submitted).Google Scholar
Jauvtis, N. & Williamson, C. H. K. 2004 The effect of two degrees of freedom on vortex-induced vibration at low mass and damping. J. Fluid Mech. 509, 2362.CrossRefGoogle Scholar
Jenny, M., Dušek, J. & Bouchet, G. 2004 Instabilities and transition of a sphere falling or ascending freely in a Newtonian fluid. J. Fluid Mech. 508, 709720.Google Scholar
Johnson, T. A. & Patel, V. C. 1999 Flow past a sphere up to a Reynolds number of 300. J. Fluid Mech. 378, 1970.Google Scholar
Karamanev, D. G., Chavarie, C. & Mayer, R. C. 1996 Dynamics of the free rise of a light solid sphere in liquid. AIChE J. 42, 17891792.Google Scholar
Kim, D., Choi, H. & Choi, H. 2005 Characteristics of laminar flow past a sphere in uniform shear. Phys. Fluids 17, 103602.Google Scholar
Kim, H. J. & Durbin, P. A. 1988 Observations of the frequencies in a sphere wake and of drag increase by acoustic excitation. Phys. Fluids 31, 32603265.CrossRefGoogle Scholar
Kuwabara, G., Chiba, S. & Kono, K. 1983 Anomalous motion of a sphere falling through water. J. Phys. Soc. Japan 52, 33733381.CrossRefGoogle Scholar
Lee, S. 2000 A numerical study of the unsteady wake behind a sphere in a uniform flow at moderate Reynolds numbers. Comput. Fluids 29, 639667.Google Scholar
Leweke, T., Provansal, M., Ormieres, D. & Lebescond, R. 1999 Vortex dynamics in the wake of a sphere. Phys. Fluids 11, S12.CrossRefGoogle Scholar
Liebster, H. 1927 Über den Widerstand von Kugeln. Ann. Phys. 82, 541562.Google Scholar
Lunnon, R. G. 1926 Fluid resistance to moving spheres. Proc. R. Soc. Lond. A 110, 302326.Google Scholar
Lunnon, R. G. 1928 Fluid resistance to moving spheres. Proc. R. Soc. Lond. A 118, 680694.Google Scholar
MacCready, P. B. & Jex, H. R. 1964 Study of sphere motion and balloon wind sensors. Tech. Rep. Tech. Mem. X53089. NASA.Google Scholar
Magarvey, R. H. & Bishop, R. L. 1961 a Transition ranges for three-dimensional wakes. Can. J. Phys. 39, 14181422.Google Scholar
Magarvey, R. H. & Bishop, R. L. 1961 b Wakes in liquid-liquid systems. Phys. Fluids 4, 800805.Google Scholar
Magnaudet, J. & Eames, I. 2000 The motion of high Reynolds number bubbles in inhomogeneous flows. Annu. Rev. Fluid Mech. 32, 659708.Google Scholar
Mittal, R. 1999 A Fourier-Chebyshev spectral collocation method for simulating flow past spheres and spheroids. Intl J. Numer. Methods Fluids 30, 921937.Google Scholar
Mittal, R., Wilson, J. J. & Najjar, F. M. 2002 Symmetry properties of the transitional sphere wake. AIAA J. 40, 579582.Google Scholar
Möller, W. 1938 Experimentelle Untersuchungen zur Hydrodynamik der Kugel. Physik. Zeit. 39, 5880.Google Scholar
Mougin, G. & Magnaudet, J. 2002 Wake-induced forces and torques on a zigzagging/spiralling bubble. Phys. Rev. Lett 88, 014502.CrossRefGoogle Scholar
Mougin, G. & Magnaudet, J. 2006 Path instability of a rising bubble. J. Fluid Mech. 567, 185194.Google Scholar
Murrow, H. N. & Henry, R. M. 1965 Self-induced balloon motions. J. Appl. Meteorol. 4, 131138.Google Scholar
Natarajan, R. & Acrivos, A. 1993 The instability of the steady flow past spheres and disks. J. Fluid Mech. 254, 323344.CrossRefGoogle Scholar
Newton, I. 1726 Philosophia Naturalis Principia Mathematica, 3rd edn. Translated by Cohen, I. B. and Whitman, A., University of California Press, 1999.Google Scholar
Prasad, A. & Williamson, C. H. K. 1997 The instability of the shear layer separating from a bluff body. J. Fluid Mech. 333, 375402.Google Scholar
Preukschat, A. W. 1962 Measurements of drag coefficients for falling and rising spheres in free motion. Master's thesis, California Institute of Technology, Pasadena, CA.Google Scholar
Quinn, J. A., Lin, C. H. & Anderson, J. L. 1986 Measuring diffusion coefficients by Taylor's method of hydrodynamic stability. AIChE J. 32, 20282033.CrossRefGoogle Scholar
Richardson, J. F. & Zaki, W. N. 1954 Sedimentation and fluidisation: part I. Trans. Inst. Chem. Engrs 32, 3553.Google Scholar
Sakamoto, H. & Haniu, H. 1990 A study on vortex shedding from spheres in a uniform flow. J. Fluids Engng 112, 386392.Google Scholar
Schlichting, H. 1955 Boundary Layer Theory. McGraw-Hill.Google Scholar
Schmidt, F. S. 1920 Zur beschleunigten Bewegung kugelförmiger Körper in widerstehenden Mitteln. J. Fluid Mech. 61, 633663.Google Scholar
Schmiedel, J. 1928 Experimentelle Untersuchungen über die Fallbewegung von Kugeln und Scheiben in reibenden Flüssigkeiten. Physik. Zeit. 17, 593610.Google Scholar
Scoggins, J. R. 1964 Aerodynamics of spherical balloon wind sensors. J. Geophys. Res. 69, 591598.Google Scholar
Shafrir, U. 1965 Horizontal oscillations of falling spheres. Tech. Rep. AFCRL 65-141. Air Force Cambridge Research Laboratories.Google Scholar
Shakespear, G. A. 1914 Experiments on the resistance of the air to falling spheres. Phil. Mag. Ser. 6 28, 728734.CrossRefGoogle Scholar
Stringham, G. E., Simons, D. B. & Guy, H. P. 1969 The behaviour of large particles falling in quiescent liquids. US Geological Survey Professional Paper 562C.CrossRefGoogle Scholar
Tomboulides, A. G. & Orszag, S. A. 2000 Numerical investigation of transitional and turbulent flow past a sphere. J. Fluid Mech. 416, 4573.Google Scholar
Veldhuis, C. & Biesheuvel, A. 2007 An experimental study of the regimes of motion of spheres falling or ascending freely in a Newtonian fluid. Intl J. Multiph. Flow 33, 10741087.Google Scholar
Veldhuis, C. H. J., Biesheuvel, A. & Lohse, D. 2009 Freely rising light solid spheres. Intl J. Multiph. Flow 35, 312322.Google Scholar
Veldhuis, C., Biesheuvel, A., van Wijngaarden, L. & Lohse, D. 2005 Motion and wake structure of spherical particles. Nonlinearity 18, C1C8.Google Scholar
Wieselsberger, C. 1921 Neuere Feststellungen über die Gesetze des Flüssigkeits- und Luftwiderstandes. Physik. Zeit. 22, 321328.Google Scholar
Williamson, C. H. K. & Govardhan, R. N. 2004 Vortex-induced vibrations. Annu. Rev. Fluid Mech. 36, 413455.CrossRefGoogle Scholar
Williamson, C. H. K. & Roshko, A. 1988 Vortex formation in the wake of an oscillating cylinder. J. Fluids Struct. 2, 355381.Google Scholar
Wu, M. & Gharib, M. 2002 Experimental studies on the shape and path of small air bubbles rising in clean water. Phys. Fluids 14, L49L52.Google Scholar