When de hotter cools more quickly: Mpemba effect in granular fluids Articles uri icon

publication date

  • October 2017

start page

  • 148001-1

end page

  • 148001-6


  • 14


  • 119

international standard serial number (ISSN)

  • 0031-9007

electronic international standard serial number (EISSN)

  • 1079-7114


  • 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.


  • Kinetic theory
    Nonequilibrium & irreversible thermodynamics
    Thermal properties
    Granular flows
    Granular fluids
    Vibrofluidized granular materials
    Boltzmann theory
    Monte Carlo methods