arXiv subjects

Gustavo M. Rodríguez-Liñán

Publications and source records attributed to Gustavo M. Rodríguez-Liñán.

5 recordsLinked to original sources

arXiv2025

Superheating and melting phenomena of a vibrated granular layer of cubic particles

We report the combined results of experiments and molecular dynamics simulations conducted to investigate superheating phenomena in vertically vibrated granular matter. Specifically, we consider a system of cubic particles densely packed in a square-lattice array and subjected to different shaking strengths, denoted by Gamma, approaching a critical value Gamma_c. Below Gamma_c, the superheated crystalline array remains indefinitely stable. Above Gamma_c, it transitions progressively into a granular liquid-like state over a Gamma-dependent timescale tau. We show that while an increase in frictional contacts significantly prolongs the lifetime of the superheated crystalline state, it does not play a major role in the scaling laws governing how that lifetime depends on shaking strength. Our findings also show that the transition from the superheated solid to the liquid state in the vibrated system is well described by a Kolmogorov-Johnson-Mehl-Avrami (KJMA) equation, which is commonly used to model phase transformations in thermal systems.

cond-mat.soft↗

arXiv2018

Granular beads in a vibrating, quasi two-dimensional cell: The true shape of the effective pair potential

Steady-state pair correlations between inelastic granular beads in a vertically shaken, quasi two-dimensional cell can be mapped onto the particle correlations in a truly two-dimensional reference fluid in thermodynamic equilibrium. Using Granular Dynamics simulations and Iterative Ornstein--Zernike Inversion, we demonstrate that this mapping applies in a wide range of particle packing fractions and restitution coefficients, and that the conservative reference particle interactions are simpler than it has been reported earlier. The effective potential appears to be a smooth, concave function of the particle distance $r$. At low packing fraction, the shape of the effective potential is compatible with a one-parametric fit function proportional to $r^{-2}$.

cond-mat.soft↗

arXiv2017

Runout transition and clustering instability observed in binary-mixture avalanche deposits

Binary mixtures of dry grains avalanching down a slope are experimentally studied in order to determine the interaction among coarse and fine grains and their effect on the deposit morphology. The distance travelled by the massive front of the avalanche over the horizontal plane of deposition area is measured as a function of mass content of fine particles in the mixture, grain-size ratio, and flume tilt. A sudden transition of the runout is detected at a critical content of fine particles, with a dependence on the grain-size ratio and flume tilt. This transition is explained as two simultaneous avalanches in different flowing regimes (a viscous-like one and an inertial one) competing against each other and provoking a full segregation and a split-off of the deposit into two well-defined, separated deposits. The formation of the distal deposit, in turn, depends on a critical amount of coarse particles. This allows the condensation of the pure coarse deposit around a small, initial seed cluster, which grows rapidly by braking and capturing subsequent colliding coarse particles. For different grain-size ratios and keeping a constant total mass, the change in the amount of fines needed for the transition to occur is found to be always less than 7%. For avalanches with a total mass of 4 kg we find that, most of the time, the runout of a binary avalanche is larger than the runout of monodisperse avalanches of corresponding constituent particles, due to lubrication on the coarse-dominated side or to drag by inertial particles on the fine-dominated side.

physics.geo-ph↗

arXiv2016

Clustering-induced attraction in granular mixtures of rods and spheres

Depletion-induced aggregation of rods enhanced by clustering is observed to produce a novel model of attractive pairs of rods separated by a line of spheres in a quasi-2D, vertically-shaken, granular gas of rods and spheres. We show that the stability of these peculiar granular aggregates increases as a function of shaking intensity. Velocity distributions of spheres inside and outside of a pair of rods trapping a line of spheres show a clear suppression of the momentum acquired by the trapped spheres. The condensed phase formed between the rods is caused by a clustering instability of the trapped spheres, enhanced by a vertical guidance produced by the confining rods. The liberated area corresponding to direct excluded-volume pairs and indirect depletion-aggregated pairs is measured as a function of time. The stability of rod pairs mediated by spheres reveals an attraction comparable in strength to the one purely induced by depletion forces.

cond-mat.soft↗

arXiv2013

Role of the granular nature of meteoritic projectiles in impact crater morphogenesis

By means of novel volume-diameter aspect ratio diagrams, we ponder on the current conception of crater morphogenesis analyzing crater data from beam explosions, hypervelocity collisions and drop experiments and comparing them with crater data from three moons (the Moon, Callisto, and Ganymede) and from our own experimental results. The distinctive volume-diameter scaling laws we discovered make us to conclude that simple and complex craters in satellites and planets could have been formed by granular vs. granular collisions and that central peaks and domes in complex craters were formed by a dynamic confinement of part of the impacting projectile, rather than by the uplift of the target terrain. A granulometric analysis of asteroids and central peaks and domes inside complex craters, shows boulder size distributions consistent with our hypothesis that crater internal features are the remnants of granular impactors.

astro-ph.EP↗