Hostname: page-component-788cddb947-w95db Total loading time: 0 Render date: 2024-10-15T01:14:20.227Z Has data issue: false hasContentIssue false

On the transient motion of ordered suspensions of liquid drops

Published online by Cambridge University Press:  26 April 2006

C. Pozrikidis
Affiliation:
Department of Applied Mechanics and Engineering Sciences, University of California at San Diego, La Jolla, CA 92093–0411, USA

Abstract

The transient motion of ordered suspensions of liquid drops, initially arranged on a cubic lattice, is studied as a model of suspension rheology. An asymptotic three-term expansion for the effective stress tensor of a dilute suspension of spherical drops is derived based on the Faxén law for the stresslet. Comparisons with available exact results for cubic lattices suggests that the expansion is remarkably accurate even at concentrations close to maximum packing. The behaviour of suspensions with recurrent structure evolving under the influence of a simple shear flow is investigated, and the results show that the time-averaged behaviour may differ substantially from the instantaneous behaviour. Transient normal stress differences may vanish in the mean, but make appreciable contributions to the instantaneous dynamics. The effect of particle deformation is assessed by numerically computing the motion of initially spherical drops arranged on a cubic lattice. At large times, the suspension is shown to exhibit periodic motions in which the drops oscillate about a mean shape with a phase shift which depends on the geometry of the lattice and the physical properties of the fluids. It is shown that drop deformations cause shear thinning and some type of elastic behaviour, and may lower the effective viscosity of the suspension below that corresponding to the dilute limit.

Type
Research Article
Copyright
© 1993 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

Ackerson, J. & Clark, N. A. 1983 Sheared colloidal suspensions. Physica 118A, 221249.Google Scholar
Acrivos, A. & Chang, E. Y. 1987 The transport properties of non-dilute suspensions. Renormalization via an effective continuum model. AIP Conf. Proc. on Physics and Chemistry of Porous Media II, vol. 154, pp. 129142.Google Scholar
Adler, P. M. 1984 Spatially periodic suspensions of convex particles in linear shear flow. IV. Three-dimensional flow. J. Méc. Théor. Appl. 3, 725746.Google Scholar
Adler, P. M. & Brenner, H. 1985 Spatially periodic suspensions of convex particles in linear shear flows. I. Description and Kinematics. Intl J. Multiphase Flow 11, 361385.Google Scholar
Adler, P.M., Zuzovsky, M. & Brenner, H. 1985 Spatially periodic suspensions of convex particles in linear shear flows. II. Rheology. Intl J. Multiphase Flow 11, 387417.Google Scholar
Beenaker, C. W. J. 1986 Ewald sum of the Rotne–Prager tensor. J. Chem. Phys. 85, 15811582.Google Scholar
Brady, J. F., Phillips, R. J., Lester, J. C. & Bossis, G. 1988 Dynamic simulation of hydrodynamically interacting suspensions. J. Fluid Mech. 195, 257280.Google Scholar
Edwards, D. A. & Wasan, D. T, 1991 A mieromechanical model of linear surface rheological behavior. Chem. Engng Sci. 46, 12471257.Google Scholar
Frankel, N. A. & Acrivos, A. 1967 On the viscosity of a concentrated suspension of solid spheres. Chem. Engng Sci. 22, 847853.Google Scholar
Hasimoto, H. 1959 On the periodic fundamental solutions of the Stokes equations and their application to viscous flow past a cubic array of spheres. J. Fluid Mech. 5, 317328.Google Scholar
Hinch, E. J. 1991 Perturbation Methods. Cambridge University Press.
Hoffman, R. L. 1972 Discontinuous and dilatant viscosity behavior in concentrated suspensions I. Observation of a now instability. Trans. Soc. Rheol. 16, 155173.Google Scholar
Hoffman, R. L. 1974 Discontinuous and dilatant viscosity behavior in concentrated suspensions II. Theory and Experimental Tests. J. Colloid Interface Set. 46, 491506.Google Scholar
Hurd, A. J., Clark, N. A., Mockler, R. C. & O'Sullivan, W. J. 1985 Friction factors for a lattice of Brownian particles. J. Fluid Mech. 153, 401416.Google Scholar
Kapral, R. & Bedeaux, D. 1978 The effective shear viscosity of a regular array of suspended spheres. Physica 91A, 590602.Google Scholar
Kim, S. & Lu, S.-Y. 1987 The functional similarity between Faxén relations and singularity solutions for fluid-fluid, fluid-solid and solid–solid dispersions. Intl J. Multiphase Flow 13, 837844.Google Scholar
Longuet-Higgins, M. S. & Cokelet, E. D. 1976 The deformation of steep surface waves on water I. A numerical method of computation. Proc. R, Soc. Lond. A 350, 126.Google Scholar
Marrucci, G. & Denn, M. M. 1985 On the viscosity of a concentrated suspension of solid spheres. Rheol. Ada 24, 317320.Google Scholar
Nijboer, B. R. A. & De Wette, P. W. 1957 On the calculation of lattice sums. Physica 23, 309321.Google Scholar
Nitsche, L. C. & Brenner, H. 1989 Eulerian kinematics of flow through spatially periodic models of porous media. Arch. Rat. Mech. 107, 225292.Google Scholar
Nunan, K. C. & Keller, J. B. 1984 Effective viscosity of a periodic suspension. J. Fluid Mech. 142, 269287.Google Scholar
Phan-Thien, N., Tran-Cong, T. & Graham, A. L. 1991 Shear flow of periodic arrays of particle clusters: a boundary-element method. J. Fluid Mech. 228, 275293.Google Scholar
Pozrikidis, C. 1992 Boundary Integral and Singularity Methods for Linearized Viscous Flow. Cambridge University Press.
Rallison, J. M. 1978 Note on the Faxén relations for a particle in Stokes flow. J. Fluid Mech. 88, 529533.Google Scholar
Rallison, J. M. 1984 The deformation of small viscous drops and bubbles in shear flows. Ann. Rev. Fluid Mech. 16, 4566.Google Scholar
Saffman, P. G. 1973 On the settling speed of free and fixed suspensions. Stud. Appl. Maths 52, 115127.Google Scholar
Sangani, A. S. 1987 Sedimentation in ordered emulsions of drops at low Reynolds numbers. Z. Angew. Math. Phys. 38, 542556.Google Scholar
Sangani, A. S. & Acrivos, A. 1982 Slow flow through a periodic array of spheres. Intl J. Multiple Flow 8, 343360.Google Scholar
Sangani, A. S. & Lu, W. 1987 Effective viscosity of an ordered suspension of small drops. Z. Angew. Math. Phys. 38, 557572.Google Scholar
Secomb, T. W., Fischer, T. M. & Skalak, R. 1983 The motion of close-packed red blood cells in shear flow. Biorheol. 20, 283294.Google Scholar
Taylor, G. I. 1932 The viscosity of a fluid containing small drops of another fluid. Proc. R. Soc. Lond. A 138, 4148.Google Scholar
Taylor, G.I. 1934 The formation of emulsions in definable fields of flow. Proc. R. Soc. Lond. A 146, 501523.Google Scholar
Thomas, D. G. 1965 Transport characteristics of suspensions: VIII. A note on the viscosity of Newtonian suspensions of uniform spherical particles. J. Colloid Sci. 20, 267277.Google Scholar
Wang, M. L. & Cheau, T.-C. 1990 Singular behavior of the effective viscosity in a concentrated suspension medium. Chem. Engng Cummun. 87, 143161.Google Scholar
Zick, A. A. & Homsy, G. M. 1982 Stokes flow through periodic arrays of spheres. J. Fluid Mech. 115, 1326.Google Scholar
Zuzovsky, M., Adler, P.M. & Brenner, H. 1983 Spatially periodic suspensions of convex particles in linear shear flows. III. Dilute arrays of spheres suspended in Newtonian fluids. Phys. Fluids 26, 17141723.Google Scholar