Abstract
We investigate the role of gravity on convection in a dense granular shear flow. Using a microgravity-modified Taylor-Couette shear cell under the conditions of parabolic flight microgravity, we demonstrate experimentally that secondary, convective-like flows in a sheared granular material are close to zero in microgravity and enhanced under high-gravity conditions, though the primary flow fields are unaffected by gravity. We suggest that gravity tunes the frictional particle-particle and particle-wall interactions, which have been proposed to drive the secondary flow. In addition, the degree of plastic deformation increases with increasing gravitational forces, supporting the notion that friction is the ultimate cause.
- Received 31 July 2012
- Publisher error corrected 7 January 2013
DOI:https://doi.org/10.1103/PhysRevLett.110.018307
© 2013 American Physical Society
Corrections
7 January 2013
Erratum
Publisher’s Note: Granular Convection in Microgravity [Phys. Rev. Lett. 110, 018307 (2013)]
N. Murdoch, B. Rozitis, K. Nordstrom, S. F. Green, P. Michel, T.-L. de Lophem, and W. Losert
Phys. Rev. Lett. 110, 029902 (2013)
Synopsis
Grain Flow Relies on Gravity
Published 3 January 2013
Previously observed convection in granular materials is now shown to be driven in part by the force of gravity, according to new microgravity experiments.
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