Apparent slip at the surface of a ball spinning in a concentrated suspension.
- Massachusetts Institute of Technology, Cambridge, MA
- Los Alamos National Laboratory, Los Alamos, NM
- University of New Mexico, Albuquerque, NM
The couple on a ball rotating relative to an otherwise quiescent suspension of comparably-sized, neutrally buoyant spheres is studied both experimentally and numerically. Apparent 'slip' relative to the analytical solution for a sphere spinning in a Newtonian fluid (based upon the viscosity of the suspension) is determined in suspensions with volume fractions c ranging from 0.03 to 0.50. This apparent slip results in a decrease of the measured torque on the spinning ball when the radius of the ball becomes comparable with that of the suspended spheres. Over the range of our data, the slip becomes more pronounced as the concentration c increases. At c = 0.25, three-dimensional boundary-element simulations agree well with the experimental data. Moreover, at c = 0.03, good agreement exists between such calculations and theoretical predictions of rotary slip in dilute suspensions.
- Research Organization:
- Sandia National Laboratories
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 953337
- Report Number(s):
- SAND2004-2919J
- Journal Information:
- Proposed for publication in the Journal of Fluid Mechanics., Journal Name: Proposed for publication in the Journal of Fluid Mechanics.
- Country of Publication:
- United States
- Language:
- English
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