Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-20T10:59:20.606Z Has data issue: false hasContentIssue false

Optical studies on the turbulent motion of solid particles in a pipe flow

Published online by Cambridge University Press:  26 April 2006

James B. Young
Affiliation:
Department of Chemical Engineering, University of Illinois, Urbana, IL 01801, USA
Thomas J. Hanratty
Affiliation:
Department of Chemical Engineering, University of Illinois, Urbana, IL 01801, USA

Abstract

An extension of an axial viewing optical technique (first used by Lee, Adrian & Hanratty) is described which allows the determination of the turbulence characteristics of solid particles being transported by water in a pipe. Measurements are presented of the mean radial velocity, the mean rate of change radial velocity, the mean-square of the radial and circumferential fluctuations, the Eulerian turbulent diffusion coefficient, and the Lagrangian turbulent diffusion coefficient. A particular focus is to explore the influence of slip velocity for particles which have small time constants. It is found that with increasing slip velocity the magnitude of the turbulent velocity fluctuations remains unchanged but that the turbulent diffusivity decreases. The measurements of the average rate of change of particle velocity are consistent with the notion that particles move from regions of high fluid turbulence to regions of low fluid turbulence. Measurements of the root-mean-square of the fluctuations of the rate of change of particle velocity allow an estimation of the average magnitude of the particle slip in a highly turbulent flow, which needs to be known to analyse the motion of particles not experiencing a Stokes drag.

Type
Research Article
Copyright
© 1991 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

Caporaloni, M., Tampieri, F. Trombetti, F. & Vittori, O. 1975 Transfer of particles in nonisotropic air turbulence. J. Atmos. Sci. 32, 565568.Google Scholar
Csanady, G. T. 1963 Turbulent diffusion of heavy particles in the atmosphere. J. Atmos. Sci. 20, 201208.Google Scholar
Gouesbet, G., Desjonqueres, P. & Berlemont, A. 1988 Eulerian and Lagrangian approaches to turbulent dispersion of particles in transient phenomena in multiphase flow (ed. N. H. Afgan). Hemisphere.
Hinze, J. O. 1975 Turbulence, 2nd edn. McGraw Hill.
Laufer, J. 1954 The structure of turbulence in fully-developed pipe flow. NACA Rep. no. 1174.Google Scholar
Lee, M. M., Hanratty, T. J. & Adrian, R. J. 1989 An axial viewing photographic technique to study turbulence characteristics of particles. Intl J, Multiphase Flow 15, 787802.Google Scholar
Lyons, S. L. 1989 A direct numerical simulation of fully developed turbulence channel flow with passive heat transfer. PhD thesis, University of Illinois, Urbana.
McCoy, D. D. & Hanratty, T. J. 1977 Rate of deposition of droplets in annular two-phase flow. Intl J. Multiphase Flow 3, 319.Google Scholar
McLaughlin, J. B. 1991 Inertial migration of a small sphere in linear shear flows. J. Fluid Mech. 224, 261274.Google Scholar
Maxey, M. R. & Riley, J. J. 1983 Equation of motion for a small rigid sphere in a nonuniform flow. Phys. Fluids 26, 883889.Google Scholar
Nir, A. & Pismen, L. M. 1979 The effect of steady drift on the dispersion of a particle in a turbulent field. J, Fluid Mech. 94, 369.Google Scholar
Pismen, L. M. & Nib, A. 1978 On the motion of suspended particles in stationary homogeneous turbulence. J. Fluid Mech. 84, 193.Google Scholar
Reeks, M. W. 1977 On the dispersion of small particles suspended in an isotropic turbulent fluid, J. Fluid Mech. 83, 529.Google Scholar
Reeks, M. W. 1983 The transport of discrete particles in inhomogeneous turbulence. J. Aerosol Science 14, 729739.Google Scholar
Risk, M. A. & Elghobashi, S. E. 1985 On the motion of a spherical particle suspended in a turbulent flow near a plane wall. Phys. Fluids 28, 806817.Google Scholar
Saffman, P. G. 1965 The lift on a small sphere in a slow shear flow. J. Fluid Mech. 22, 385.Google Scholar
Saffman, P. G. 1968 Corrigendum to 'The lift on a small sphere in a slow shear flow'. J. Fluid Mech. 31, 624.Google Scholar
Taylor, G. I. 1921 Diffusion by continuous movements. Proc. Lond. Math. Soc. 151, 196.Google Scholar
Vames, J. S. & Hanratty, T. J. 1988 Turbulent dispersion of droplets for air flow in a pipe. Exps Fluids 6, 94104.Google Scholar
Young, J. B. 1989 An experimental study of solid particle motion in a turbulent liquid pipe flow. PhD thesis, University of Illinois, Urbana.
Yudine, M. I. 1959 Physical considerations on heavy particle diffusion. Atmospheric Diffusion and Air Pollution Adv. Geophys. 6, 185.Google Scholar