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arXiv · 1610.09872

Microscopic statistical description of incompressible Navier-Stokes granular fluids

Massimo Tessarotto·Michael Mond·Claudio Asci
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Abstract

Based on the recently-established Master kinetic equation and related Master constant H-theorem which describe the statistical behavior of the Boltzmann-Sinai classical dynamical system for smooth and hard spherical particles, the problem is posed of determining a microscopic statistical description holding for an incompressible Navier-Stokes fluid. The goal is reached by introducing a suitable mean-field interaction in the Master kinetic equation. The resulting Modified Master Kinetic Equation (MMKE) is proved to warrant at the same time the condition of mass-density incompressibility and the validity of the Navier-Stokes fluid equation. In addition, it is shown that the conservation of the Boltzmann-Shannon entropy can similarly be warranted. Applications to the plane Couette and Poiseuille flows are considered showing that they can be regarded as final decaying states for suitable non-stationary flows. As a result, it is shown that an arbitrary initial stochastic $1-$body PDF evolving in time by means of MMKE necessarily exhibits the phenomenon of Decay to Kinetic Equilibrium (DKE), whereby the $1-$body PDF asymptotically relaxes to a stationary and spatially-uniform Maxwellian PDF.

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Massimo Tessarotto, Michael Mond, Claudio Asci. 2016-10-31. Microscopic statistical description of incompressible Navier-Stokes granular fluids. https://arxiv.org/abs/1610.09872

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