Andrés Santos

Dr. Andrés Santos

Universidad de Extremadura (Spain)
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Research Focus & Metrics

Academic Career Length

49Years (1978-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 1998 in Physical Review E
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JBJ. Javier Brey
J. Javier Brey
JDJames W. Dufty
James W. Dufty
CKChang Sub Kim
Chang Sub Kim
Andrés SantosAndrés Santos
Andrés Santos
The hydrodynamic equations for a gas of hard spheres with dissipative dynamics are derived from the Boltzmann equation. The heat and momentum fluxes are calculated to Navier-Stokes order and the transport coefficients are determined as explicit functions of the coefficient of restitution. The dispersion relations for the corresponding linearized equations are obtained and the stability of this linear description is discussed. This requires consideration of the linear Burnett contributions to the energy balance equation from the energy sink term. Finally, it is shown how these results can be imbedded in simpler kinetic model equations with the potential for analysis of more complex states.

4 October 2017 in Physical Review Letters
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ALAntonio Lasanta
Antonio Lasanta
FRFrancisco Vega Reyes
Francisco Vega Reyes
Antonio PradosAntonio Prados
Antonio Prados
Andrés SantosAndrés Santos
Andrés Santos
Under certain conditions, two samples of fluid at different initial temperatures present a counterintuitive behavior known as the Mpemba effect: it is the hotter system that cools sooner. Here, we show that the Mpemba effect is present in granular fluids, both in uniformly heated and in freely cooling systems. In both cases, the system remains homogeneous, and no phase transition is present. Analytical quantitative predictions are given for how differently the system must be initially prepared to observe the Mpemba effect, the theoretical predictions being confirmed by both molecular dynamics and Monte Carlo simulations. Possible implications of our analysis for other systems are also discussed.

1 June 1997 in Journal of Statistical Physics
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JBJ. Javier Brey
J. Javier Brey
JDJames W. Dufty
James W. Dufty
Andrés SantosAndrés Santos
Andrés Santos

1 May 2000 in Granular Matter
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JMJosé María Montanero
José María Montanero
Andrés SantosAndrés Santos
Andrés Santos

1 February 1989 in Physics of Fluids A: Fluid Dynamics
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Vicente GarzóVicente Garzó
Vicente Garzó
Andrés SantosAndrés Santos
Andrés Santos
JBJ. Javier Brey
J. Javier Brey
A kinetic model for a dilute multicomponent gas system is proposed. It is constructed by replacing the Boltzmann collision operator with a relaxation-time term, in the same manner as in the Bhatnagar–Gross–Krook (BGK) model for a single gas. The model contains several parameters that are determined by keeping some of the main properties of the Boltzmann description. In contrast to previous works, the BGK equation is recovered when mechanically identical particles are considered. Thus the model can be expected to apply to systems in which masses are comparable. The transport properties to the Navier–Stokes level are studied and Onsager’s reciprocal relations are found to hold.

1 October 1999 in Journal of Statistical Physics
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Journal Article
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JBJ. Javier Brey
J. Javier Brey
JDJames W. Dufty
James W. Dufty
Andrés SantosAndrés Santos
Andrés Santos