Lattice models for granular-like velocity fields: finite-size effects

2016 • In *Journal of Statistical Mechanics: Theory and Experiment*

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Abstract :

[en] Long-range spatial correlations in the velocity and energy fields of a granular fluid are discussed in the framework of a 1d lattice model. The dynamics of the velocity field occurs through nearest-neighbour inelastic collisions that conserve momentum but dissipate energy. A set of equations for the fluctuating hydrodynamics of the velocity and energy mesoscopic fields give a first approximation for (i) the velocity structure factor and (ii) the finite-size correction to the Haff law, both in the homogeneous cooling regime. At a more refined level, we have derived the equations for the two-site velocity correlations and the total energy fluctuations. First, we seek a perturbative solution thereof, in powers of the inverse of system size. On the one hand, when scaled with the granular temperature, the velocity correlations tend to a stationary value in the long time limit. On the other hand, the scaled standard deviation of the total energy diverges, that is, the system shows multiscaling. Second, we find an exact solution for the velocity correlations in terms of the spectrum of eigenvalues of a certain matrix. The results of numerical simulations of the microscopic model confirm our theoretical results, including the above described multiscaling phenomenon.

Disciplines :

Physics

Plata, Carlos

Manacorda, Alessandro ^{}; Università degli Studi di Roma "La Sapienza"

Lasanta, Antonio

Prados, Antonio

Puglisi, Andrea

External co-authors :

yes

Language :

English

Title :

Lattice models for granular-like velocity fields: finite-size effects

Publication date :

12 September 2016

Journal title :

Journal of Statistical Mechanics: Theory and Experiment

ISSN :

1742-5468

Publisher :

Institute of Physics, Bristol, United Kingdom

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

Scopus citations^{®}

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Scopus citations^{®}

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11

WoS citations^{™}

8