Article
Physics, Fluids & Plasmas
Joyjit Chattoraj, Nguyen Hoang Huy, Saurabh Aggarwal, Mohamed Salahuddin Habibullah, Farzam Farbiz
Summary: This study investigates granular flows during a shear-induced mixing process using discrete element methods. The research reveals a strain rate-dependent transition from quasistatic to purely inertial flow, as well as a correlation between mixing dynamics and the formation of shear bands at the granular scale. The results show a profound system size dependence in contact stresses at a macroscopic scale and significantly different timescales of mixing depending on the regions in the system.
Article
Engineering, Chemical
Wangxin Yu, Xiaoliang Wang, Qingquan Liu, Xuedong Chen, Huaning Wang
Summary: This study investigates the dynamic interaction between fast granular flow and an existing deposit using the Savage-Hutter model. Three distinct flow patterns are identified, and a new normal shock relationship for granular flow is proposed.
Article
History & Philosophy Of Science
Arno Schubbach
Summary: This paper addresses the lack of conceptual tools for an epistemological discussion of machine learning by conceptualizing deep learning networks as 'judging machines' and applying Kantian analysis of judgments to specify their capabilities. It emphasizes that the functionality of deep learning networks is established through training and requires a new form of justification based on Kant's epistemology.
Article
Computer Science, Interdisciplinary Applications
Mohammad Nikooei, Mehrdad T. Manzari
Summary: This paper numerically studies the interaction of flowing granular material with an entrainable granular bed, and characterizes the rheological behavior of the granular mixture using a generalized viscoplastic model. The effect of dynamics of entrained bedtype particles on rheology is considered, with discretization of flow equations using Incompressible Smoothed Particle Hydrodynamics method. Benchmark problems are solved to assess accuracy, and the impact of mixing effect on various model parameters is studied, with reported variations in momentum, velocity, and total kinetic energy of flow with time.
COMPUTERS & GEOSCIENCES
(2021)
Article
Physics, Multidisciplinary
R. Caitano, B. Guerrero, R. E. R. Gonzalez, I Zuriguel, A. Garcimartin
Summary: The study confirms the transition from clogged to unclogged state in vibrating granular media, characterizing it based on outlet size and vibration intensity. The study proposes a new control parameter for the system and observes a critical value for a continuous transition to an unclogged state, which varies with the outlet size. A phase diagram in the S-D plane shows clogging as a concave surface.
PHYSICAL REVIEW LETTERS
(2021)
Review
Environmental Sciences
Aurora Rosa-Masegosa, Barbara Munoz-Palazon, Alejandro Gonzalez-Martinez, Massimiliano Fenice, Susanna Gorrasi, Jesus Gonzalez-Lopez
Summary: The technology of aerobic granular sludge shows potential in wastewater treatment, but utilizing sequential batch reactors presents limitations. To improve efficiency, focus has shifted towards continuous flow reactors, yet satisfactory results have not been achieved.
Article
Mechanics
Laurent Lacaze, Joris Bouteloup, Benjamin Fry, Edouard Izard
Summary: This study investigates the collapse of a granular column in a liquid using numerical simulations, focusing on the influence of Stokes number St and the initial volume fraction phi(i) on the dynamics of the collapse. A dedicated numerical model with a discrete element method is used to provide a comprehensive description of the granular phase in dense granular flows. The research aims to characterize the dynamics of the collapse and its final deposit in relation to (St, phi(i)), as well as to describe the granular rheology and dilatancy effects based on these two dimensionless numbers.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Jannike Solsvik, Eirik Manger
Summary: The kinetic theory for granular mixtures considers a separate granular temperature for each solid phase, with particle phases assumed to follow a Maxwellian distribution and a zero-order approximation of the Boltzmann equation. A solution strategy is presented for solving the integrals of the collisional closure relations, allowing for the consideration of solid particle hydrodynamic velocities in the distribution function. However, the strategy limits the validity of the closure relations to relatively small and moderate hydrodynamic velocity differences, which can significantly differ from simplified models traditionally neglecting such differences.
Article
Physics, Multidisciplinary
Yi Xing, Jie Zheng, Jindong Li, Yixin Cao, Wei Pan, Jie Zhang, Yujie Wang
Summary: Through experimental study of granular systems, we have revealed the evolution of microscopic and macroscopic behaviors during shear processes, as well as the constitutive relationship of shear force.
PHYSICAL REVIEW LETTERS
(2021)
Article
Engineering, Chemical
Angga Pratama Herman, Zongyan Zhou, Jieqing Gan, Aibing Yu
Summary: This study investigates the mixing of granular materials in rotating drums with different volumes. The results show that mixing performance is affected by drum size and particle diameter. A correlation equation is proposed for predicting mixing rate, and the ratio of drum diameter to particle diameter influences particle travel distances and displacements. The findings are significant for understanding the mixing mechanism of granular materials.
Article
Engineering, Chemical
Hui Cai, Guoqing Miao
Summary: This study reported the flow pattern in a vertically vibrated, annular, and granular system, showing either laminar granular flow or turbulent granular flow in different vibration modes. The flow patterns were explained and identified using the Reynolds numbers of the granular system. The results revealed a property peculiar to the granular flow similar to, yet different from, viscous fluids.
Article
Engineering, Chemical
Quan Chen, R. Li, W. Z. Xiu, V Zivkovic, H. Yang
Summary: The experimental results show that the dynamics of the granular system in a narrowing silo during discharge is stable. Ordered particle movements may occur near the outlet. The correlation between the granular temperature distribution and the velocity vector field is opposite in different directions.
Article
Mechanics
Kun Xue, Lvlan Miu, Jiarui Li, Chunhua Bai, Baolin Tian
Summary: The explosive dispersal of granular media is challenging to control or characterize due to the complex particle-flow coupling. In this study, the central explosion-driven dispersal of dense particle layers is investigated using computational fluid dynamics-discrete element method. Different dispersal modes are categorized and corresponding thresholds are proposed based on characterizing parameters. Continuum models are also developed to identify ideal dispersal modes and provide insights into the origins of particle-scale patterns.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Fluids & Plasmas
Miles L. Morgan, David W. James, Martin Monloubou, Kristian S. Olsen, Bjornar Sandnes
Summary: This study investigates fluid-driven granular drainage in a silo with grains submerged in fluid, finding that diffusion length significantly decreases with height in contrast to dry silos. An anomalous diffusion model is proposed to describe the spreading of flow upwards in the cell, indicating a shift towards subdiffusive behavior as system viscosity increases. The shape of the flowing zone in the silo deviates further from traditional normal diffusion models, becoming more subdiffusive with a decreasing diffusion exponent.
Article
Mechanics
Giorgos Kanellopoulos
Summary: This paper focuses on the mathematical interpretation of the theoretical existence of the granular monoclinal wave, categorizing it into two classes based on the form of the waveform. The critical Froude number for stable uniform flows is determined from the stability analysis of the dynamical system.
JOURNAL OF FLUID MECHANICS
(2021)
