Velocity distribution and the effect of wall roughness in granular Poiseuille flow.
From event-driven simulations of a gravity-driven channel flow of inelastic hard disks, we show that the velocity distribution function remains close to a Gaussian for a wide range densities (even when the Knudsen number is of order 1) if the walls are smooth and the particle collisions are nearly elastic. For dense flows, a transition from a Gaussian to a power-law distribution for the high-velocity tails occurs with increasing dissipation in the center of the channel, irrespective of wall roughness. For a rough wall, the near-wall distribution functions are distinctly different from those in the bulk, even in the quasielastic limit.
Engineering Mechanics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur PO, Bangalore, India.
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KC
Vijayakumar
Meheboob
M
Alam