title: Granular convection in microgravity.
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.
authors: Laboratoire Lagrange, UMR 7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d'Azur, 06300 Nice, France. murdoch@oca.eu
authors: N
authors: N
authors: Murdoch
authors: B
authors: B
authors: Rozitis
authors: K
authors: K
authors: Nordstrom
authors: S F
authors: SF
authors: Green
authors: P
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authors: Michel
authors: T-L
authors: TL
authors: de Lophem
authors: W
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authors: Losert