From discrete particles to continuum fields in mixtures

Particle-size segregation in dense granular avalanches

“…This model can therefore explain the motion of large particles to the walls of a vertical chute flow and their rise to the surface of an avalanche in a rotating drum [16]. However, it is not yet clear that it can fully explain the rise of large particles to the surface of an avalanche in chute flow [75], where high granular temperatures develop near the base of the flow [64] rather than at the surface. If the kinetic stresses do turn 100 out to be the critical driving forces for segregation then it will be necessary to compute them as part of the solution for the bulk flow [76], which significantly complicates the model.…”

“…Note that the form (13) automatically satisfies the summation constraint ∀ν f ν = 1. One of the beauties of the mixture theory approach is that it is possible to change the model assumptions 75 to investigate different effects within the same general framework. Thornton et al [55] derived an equivalent segregation flux to (11) using a three-phase model that accounted for an inviscid interstitial fluid with intrinsic density ρ f * that differed from the density of the grains ρ g * .…”

Debris flows: Experiments and modelling

“…This model can therefore explain the motion of large particles to the walls of a vertical chute flow and their rise to the surface of an avalanche in a rotating drum [16]. However, it is not yet clear that it can fully explain the rise of large particles to the surface of an avalanche in chute flow [75], where high granular temperatures develop near the base of the flow [64] rather than at the surface. If the kinetic stresses do turn out to be the critical driving forces for segregation then it will be necessary to compute them as part of the solution for the bulk flow [76], which significantly complicates the model.…”

“…J.M.N.T. Gray et al / C. R. Physique 16 (2015) [73][74][75][76][77][78][79][80][81][82][83][84][85] jacente de grains statiques ou en déplacement lent. La combinaison de la ségrégation et des changements de phase solide-fluide granulaire crée des motifs complexes dans les dépôts résultants, mais la compréhension complète de ces effets est pour le moment hors de portée.…”

Probabilistic calibration of discrete element simulations using the sequential quasi-Monte Carlo filter

“…Current work involves probabilistic calibration of dense granular materials under quasistatic loading conditions. In future research, it will be worth investigating the applicability of the SQMC and SIS to DEM calibrations against more complex behavior of granular materials, such as rockfalls [11], avalanches [51] and silo discharges [8]. Ongoing work on probabilistic calibration of DEM simulations is directed towards the development of an iterative SQMC filter, which is capable of resampling micromechanical parameters from prior probability distributions updated by the previously conducted probabilistic calibrations.…”