01862nas a2200181   4500008004100000022001400041245010200055210006900157260010300226300001000329490000700339520113400346100002101480700001601501700001601517700002101533856012601554       2008                        eng d  a0295-507500aFast decay of the velocity autocorrelation function in dense shear flow of inelastic hard spheres0 aFast decay of the velocity autocorrelation function in dense she  a17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCEbEDP SCIENCES S AcDEC  a640030 v843 a<p>We find in complementary experiments and event-driven simulations of sheared inelastic hard spheres that the velocity autocorrelation function psi(t) decays much faster than t(-3/2) obtained for a fluid of elastic spheres at equilibrium. Particle displacements are measured in experiments inside a gravity-driven flow sheared by a rough wall. The average packing fraction obtained in the experiments is 0.59, and the packing fraction in the simulations is varied between 0.5 and 0.59. The motion is observed to be diffusive over long times except in experiments where there is layering of particles parallel to boundaries, and diffusion is inhibited between layers. Regardless, a rapid decay of psi(t) is observed, indicating that this is a feature of the sheared dissipative fluid, and is independent of the details of the relative particle arrangements. An important implication of our study is that the non-analytic contribution to the shear stress may not be present in a sheared inelastic fluid, leading to a wider range of applicability of kinetic theory approaches to dense granular matter. Copyright (C) EPLA, 2008</p>1 aOrpe, Ashish, V.1 aKumaran, V.1 aReddy, Anki1 aKudrolli, Arshad  uhttps://library.ncl.res.in/content/fast-decay-velocity-autocorrelation-function-dense-shear-flow-inelastic-hard-spheres-0