A Caltech Library Service

Local measurements of velocity fluctuations and diffusion coefficients for a granular material flow

Natarajan, V. V. R. and Hunt, M. L. and Taylor, E. D. (1995) Local measurements of velocity fluctuations and diffusion coefficients for a granular material flow. Journal of Fluid Mechanics, 304 . pp. 1-25. ISSN 0022-1120. doi:10.1017/S0022112095004320.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Measurements were made of two components of the average and fluctuating velocities, and of the local self-diffusion coefficients in a flow of granular material. The experiments were performed in a 1 m-high vertical channel with roughened sidewalls and with polished glass plates at the front and the back to create a two-dimensional flow. The particles used were glass spheres with a nominal diameter of 3 mm. The flows were high density and were characterized by the presence of long-duration frictional contacts between particles. The velocity measurements indicated that the flows consisted of a central uniform regime and a shear regime close to the walls. The fluctuating velocities in the transverse direction increased in magnitude from the centre towards the walls. A similar variation was not observed for the streamwise fluctuations. The self-diffusion coefficients showed a significant dependence on the fluctuating velocities and the shear rate. The velocity fluctuations were highly anistropic with the streamwise components being 2 to 2.5 times the transverse components. The self-diffusion coefficients for the streamwise direction were an order-of-magnitude higher than those for the transverse direction. The surface roughness of the particles led to a decrease in the self-diffusion coefficients.

Item Type:Article
Related URLs:
URLURL TypeDescription
Hunt, M. L.0000-0001-5592-2334
Additional Information:Copyright © 1995 Cambridge University Press. Reprinted with permission. (Received 24 August 1994 and in revised form 24 April 1995)
Record Number:CaltechAUTHORS:NATjfm95
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12036
Deposited By: Archive Administrator
Deposited On:21 Oct 2008 01:03
Last Modified:08 Nov 2021 22:25

Repository Staff Only: item control page