Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-19T06:38:22.884Z Has data issue: false hasContentIssue false

Stability of bounded rapid shear flows of a granular material

Published online by Cambridge University Press:  26 April 2006

Chi-Hwa Wang
Affiliation:
Department of Chemical Engineering, Princeton University, Princeton, NJ 08544, USA
R. Jackson
Affiliation:
Department of Chemical Engineering, Princeton University, Princeton, NJ 08544, USA
S. Sundaresan
Affiliation:
Department of Chemical Engineering, Princeton University, Princeton, NJ 08544, USA

Abstract

This paper presents a linear stability analysis of a rapidly sheared layer of granular material confined between two parallel solid plates. The form of the steady base-state solution depends on the nature of the interaction between the material and the bounding plates and three cases are considered, in which the boundaries act as sources or sinks of pseudo-thermal energy, or merely confine the material while leaving the velocity profile linear, as in unbounded shear. The stability analysis is conventional, though complicated, and the results are similar in all cases. For given physical properties of the particles and the bounding plates it is found that the condition of marginal stability depends only on the separation between the plates and the mean bulk density of the particulate material contained between them. The system is stable when the thickness of the layer is sufficiently small, but if the thickness is increased it becomes unstable, and initially the fastest growing mode is analogous to modes of the corresponding unbounded problem. However, with a further increase in thickness a new mode becomes dominant and this is of an unusual type, with no analogue in the case of unbounded shear. The growth rate of this mode passes through a maximum at a certain value of the thickness of the sheared layer, at which point it grows much faster than any mode that could be shared with the unbounded problem. The growth rate of the dominant mode also depends on the bulk density of the material, and is greatest when this is neither very large nor very small.

Type
Research Article
Copyright
© 1996 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

Babić, M. 1993 On the stability of rapid granular flows. J. Fluid Mech. 254, 127150.Google Scholar
Gallagher, A. P. & Mercer, A. McD. 1962 On the behaviour of small disturbances in plane Couette flow. J. Fluid Mech. 13, 91100.Google Scholar
Goldhirsch, I., Tan, M.-L. & Zanetti, G. 1993 A molecular dynamical study of granular fluids I: the unforced granular gas in two dimensions. J. Sci. Comput. 8, 140.Google Scholar
Haff, P. K. 1983 Grain flow as a fluid-mechanical phenomenon. J. Fluid Mech. 134, 401430.Google Scholar
Hopkins, M. A. & Louge, M. Y. 1991 Inelastic microstructure in rapid granular flows of smooth disks. Phys. Fluids A 3, 4757.Google Scholar
Jenkins, J. T. 1987 Rapid flows of granular materials. In Non-Classical Continuum Mechanics, pp. 213225. Cambridge University Press.
Jenkins, J. T. & Richman, M. W. 1986 Boundary conditions for plane flows of smooth, nearly elastic, circular disks. J. Fluid Mech. 171, 5369.Google Scholar
Jenkins, J. T. & Savage, S. B. 1983 A theory for the rapid flow of identical, smooth, nearly elastic, spherical particles. J. Fluid Mech. 130, 187202.Google Scholar
Johnson, P. C. & Jackson, R. 1987 Frictional-collisional constitutive relations for granular materials, with application to plane shearing. J. Fluid Mech. 176, 6793.Google Scholar
Lun, C. K. K., Savage, S. B., Jeffrey, D. J. & Chepurniy, N. 1984 Kinetic theories for granular flow; inelastic particles in Couette flow and slightly inelastic particles in a general flow field. J. Fluid Mech. 140, 223256.Google Scholar
McNamara, S. 1993 Hydrodynamic modes of a uniform granular medium. Phys. Fluids A 5, 30563070.Google Scholar
Mello, T. M., Diamond, P. H. & Levine, H. 1991 Hydrodynamic modes of a granular shear flow. Phys. Fluids A 3, 20672075.Google Scholar
Moffatt, H. K. 1967 The interaction of turbulence with strong wind shear. In Atmospheric Turbulence and Radio Wave Propagation (ed. A. M. Yaglom & V. I. Tatarsky), pp. 135156. Moscow: Nauka.
Richman, M. W. 1988 Boundary conditions based upon a modified Maxwellian velocity distribution for flows of identical, smooth, nearly elastic spheres. Acta Mechanica 75, 227240.Google Scholar
Savage, S. B. 1992 Instability of unbounded uniform granular shear flow. J. Fluid Mech. 241, 109123.Google Scholar
Schmid, P. J. & Kytömaa, H. K. 1994 Transient and asymptotic stability of granular shear flow. J. Fluid Mech. 264, 255275.Google Scholar
Thomson, W. 1887 Stability of fluid motion. Rectilineal motion of viscous fluid between two parallel planes. Phil. Mag. 24 (August), 188196.Google Scholar
Wang, C.-H. 1995 Instabilities in granular material flows. PhD dissertation, Princeton University.