We formulate the kinetic theory of dry granular particles under a simple shear based on the Enskog and Grad approximations 1,2. We get a complete set of equations for the kinetic stress and the collisional contribution to the stress within this approximation. The steady solution under this approximation reproduces quantitatively accurate results for the shear viscosity and kinetic temperature for volume fractions φ<0.5, except in nearly elastic situations. We also obtain qualitatively accurate results for the steady normal stress differences for φ<0.5. By using a protocol that reverses a shear rate satisfying Newton's equation of motion, we also discuss the relaxation dynamics required to reach the steady state. We have also observed the Mpemba effect if the initial conditions of two copied systems are not largely deviated References: 1 H. Hayakawa and S. Takada, Nonlinear rheology: Non-equilibrium statistical physics of granular materials (Springer) in press. 2 S. Iizuka, S. Takada, and H. Hayakawa, in preparation.
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