Durian, Douglas
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Condensed Matter Physics
Statistical, Nonlinear, and Soft Matter Physics
Statistical, Nonlinear, and Soft Matter Physics
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Faculty Member
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Publication Granular Discharge Rate for Submerged Hoppers(2014-01-01) Wilson, T. J; Pfeifer, C. R; Meysingier, N.; Durian, Douglas JThe discharge of spherical grains from a hole in the bottom of a right circular cylinder is measured with the entire system underwater. We find that the discharge rate depends on filling height, in contrast to the well-known case of dry non-cohesive grains. It is further surprising that the rate increases up to about twenty five percent, as the hopper empties and the granular pressure head decreases. For deep filling, where the discharge rate is constant, we measure the behavior as a function of both grain and hole diameters. The discharge rate scale is set by the product of hole area and the terminal falling speed of isolated grains. But there is a small-hole cutoff of about two and half grain diameters, which is larger than the analogous cutoff in the Beverloo equation for dry grains.Publication Low-Speed Impact Craters in Loose Granular Media(2003-05-16) Uehara, J. S; Ambroso, M. A; Ojha, R.; Durian, Douglas JWe report on craters formed by balls dropped into dry, noncohesive, granular media. By explicit variation of ball density ρb, diameter Db, and drop height H, the crater diameter is confirmed to scale as the 1/4 power of the energy of the ball at impact: Dc∼(ρbD3bH)1/4. Against expectation, a different scaling law is discovered for the crater depth: d ∼ (ρ3/2bD2bH)1/3. The scaling with properties of the medium is also established. The crater depth has significance for granular mechanics in that it relates to the stopping force on the ball.Publication Making a Frothy Shampoo or Beer(2010-05-01) Durian, Douglas; Raghavan, Srinivasa RPublication Divergence of Voronoi Cell Anisotropy Vector: A Threshold-Free Characterization of Local Structure in Amorphous Materials(2016-02-26) Rieser, Jennifer M; Goodrich, Carl P; Durian, Douglas J; Liu, Andrea JCharacterizing structural inhomogeneity is an essential step in understanding the mechanical response of amorphous materials. We introduce a threshold-free measure based on the field of vectors pointing from the center of each particle to the centroid of the Voronoi cell in which the particle resides. These vectors tend to point in toward regions of high free volume and away from regions of low free volume, reminiscent of sinks and sources in a vector field. We compute the local divergence of these vectors, where positive values correspond to overpacked regions and negative values identify underpacked regions within the material. Distributions of this divergence are nearly Gaussian with zero mean, allowing for structural characterization using only the moments of the distribution. We explore how the standard deviation and skewness vary with the packing fraction for simulations of bidisperse systems and find a kink in these moments that coincides with the jamming transition.Publication From Avalanches to Fluid Flow: A Continuous Picture of Grain Dynamics Down a Heap(2000-11-13) Lemieux, P. A; Durian, Douglas JSurface flows are excited by steadily adding spherical glass beads to the top of a heap. To simultaneously characterize the fast single-grain dynamics and the much slower collective intermittency of the flow, we extend photon-correlation spectroscopy via fourth-order temporal correlations in the scattered light intensity. We find that microscopic grain dynamics during an avalanche are similar to those in the continuous flow just above the transition. We also find that there is a minimum jamming time, even arbitrarily close to the transition.Publication Bubble Kinetics in a Steady-State Column of Aqueous Foam(2006-10-13) Feitosa, K.; Kamien, Randall D; Halt, O. L; Durian, Douglas JWe measure the liquid content, the bubble speeds, and the distribution of bubble sizes, in a vertical column of aqueous foam maintained in steady state by continuous bubbling of gas into a surfactant solution. Nearly round bubbles accumulate at the solution/foam interface, and subsequently rise with constant speed. Upon moving up the column, they become larger due to gas diffusion and more polyhedral due to drainage. The size distribution is monodisperse near the bottom and polydisperse near the top, but there is an unexpected range of intermediate heights where it is bidisperse with small bubbles decorating the junctions between larger bubbles. We explain the evolution in both bidisperse and polydisperse regimes, using Laplace pressure differences and taking the liquid fraction profile as a given.Publication Spatially Heterogeneous Dynamics in a Granular System Near Jamming(2007-01-01) Abate, A. R; Durian, Douglas JIn supercooled liquids and dense colloidal suspensions, strings of correlated motion represent a dynamical correlation length that grows as the glass transition is approached. Here, we present a granular system driven close to the jamming transition that shares this hallmark dynamical feature. In analogy, it exhibits a dynamical length scale that grows as the jamming transition is approached.Publication Nonlinear Bubble Dynamics in a Slowly Driven Foam(1995-09-25) Gopal, A. D.; Durian, Douglas JSudden topological rearrangement of neighboring bubbles in a foam occur during coarsening, and can also be induced by applied forces. Diffusing-wave spectroscopy measurements are presented of such dynamics before, during, and after an imposed shear strain. The rate of rearrangements is proportional to the strain rate, and the shape of the correlation functions shows that they are spatially and temporally uncorrelated. Macroscopic deformation is thus accomplished by a nonlinear microscopic process reminiscent of dynamics in the propagation of earthquake faults or the flow of granular media.Publication Structure and Coarsening at the Surface of a Dry Three-Dimensional Aqueous Foam(2013-12-05) Roth, R. E; Chen, B. G; Durian, Douglas JWe utilize total-internal reflection to isolate the two-dimensional surface foam formed at the planar boundary of a three-dimensional sample. The resulting images of surface Plateau borders are consistent with Plateau's laws for a truly two-dimensional foam. Samples are allowed to coarsen into a self-similar scaling state where statistical distributions appear independent of time, except for an overall scale factor. There we find that statistical measures of side number distributions, size-topology correlations, and bubble shapes are all very similar to those for two-dimensional foams. However, the size number distribution is slightly broader, and the shapes are slightly more elongated. A more obvious difference is that T2 processes now include the creation of surface bubbles, due to rearrangement in the bulk, and von Neumann's law is dramatically violated for individual bubbles. But nevertheless, our most striking finding is that von Neumann's law appears to holds on average, namely, the average rate of area change for surface bubbles appears to be proportional to the number of sides minus six, but with individual bubbles showing a wide distribution of deviations from this average behavior.Publication Rheology of Sediment Transported by a Laminar Flow(2016-12-19) Houssais, Morgane; Ortiz, Carlos P; Durian, Douglas J; Jerolmack, Douglas JUnderstanding the dynamics of fluid-driven sediment transport remains challenging, as it occurs at the interface between a granular material and a fluid flow. Boyer, Guazzelli, and Pouliquen [Phys. Rev. Lett.107, 188301 (2011)] proposed a local rheology unifying dense dry-granular and viscous-suspension flows, but it has been validated only for neutrally buoyant particles in a confined and homogeneous system. Here we generalize the Boyer, Guazzelli, and Pouliquen model to account for the weight of a particle by addition of a pressure P0 and test the ability of this model to describe sediment transport in an idealized laboratory river. We subject a bed of settling plastic particles to a laminar-shear flow from above, and use refractive-index-matching to track particles' motion and determine local rheology—from the fluid-granular interface to deep in the granular bed. Data from all experiments collapse onto a single curve of friction μ as a function of the viscous number Iv over the range 3 × 10−5≤ Iv ≤ 2, validating the local rheology model. For Iv < 3 × 10−5, however, data do not collapse. Instead of undergoing a jamming transition with μ → μs as expected, particles transition to a creeping regime where we observe a continuous decay of the friction coefficient μ ≤ μs as Iv decreases. The rheology of this creep regime cannot be described by the local model, and more work is needed to determine whether a nonlocal rheology model can be modified to account for our findings.