Article
Engineering, Chemical
A. N. Huang, T. H. Cheng, W. Y. Hsu, C. C. Huang, H. P. Kuo
Summary: DEM simulations were used to study size segregation of binary mixture in a rotating drum with inner diameter variations. The results showed that larger particle enrichment occurs in the smaller inner diameter regions. The effect of inner diameter contracting ratio (CR) on particle dynamics was further investigated, with CR of 0.9 leading to smaller particles moving towards dilated larger inner diameter regions.
Article
Engineering, Chemical
Ren Han, Jingyu Feng, Yufeng Zhang, Hui Yang, Vladimir Zivkovic, Ran Li
Summary: A numerical simulation was used to investigate the avalanche flow characteristic of particles in the slumping regime within a rotating drum. Results show that the growth rate of avalanching particle number follows a specific pattern over time, with the distribution and propagation velocities of particles exhibiting certain regularities.
Article
Engineering, Chemical
Xiangwu Xiao, Yingying Li, Ruitao Peng, Jiangxiong Gao, Congfang Hu
Summary: In this study, the appropriate selection of physical and contact parameters in the mixing processes of gravel materials using the discrete element method was investigated. Physical parameters of irregular gravel were obtained through experiments, and contact parameters were determined using the response surface method. The mixing processes of gravel materials in a rotating drum with different cylindrical rod structures were simulated, and the number of contacts between particles was used to characterize the mixing uniformity. The results showed that cylindrical rods significantly improved mixing uniformity, with the best effect observed when the distance between cylindrical rods was twice the maximum particle size.
Article
Engineering, Chemical
Hongyu Chen, Milind A. Jog, Douglas E. Evans, Leonid A. Turkevich
Summary: Dustiness evaluation is crucial in estimating potential exposure to toxic, hazardous, or irritant powders. The Rotating Drum is a widely used instrument for assessing powder dustiness, but its aerodynamics during operation is not fully understood. Utilizing computational fluid dynamics to study the flow inside the Rotating Drum can aid in interpreting dustiness measurements and guiding manufacturing processes to generate less dust.
Article
Engineering, Chemical
Sunil Kumar, Salma Khatoon, Shivam Parashar, Praveen Dubey, Jeetram Yogi, Anshu Anand
Summary: In this study, the Discrete Element Method (DEM) is used to investigate the evolution of radial segregation in binary mixtures and its dependence on the particle's aspect ratio. A total of 37 different types of binary mixtures were created, varying the particle's aspect ratio from 0.25 to 4.0. The results show that both the aspect ratio of coarse and fine particles influence mixing. The initial well-mixed binary mixture evolves into a radial segregated state, with fine particles occupying the central core and coarse particles surrounding them. Spherical particles promote segregation regardless of their role as coarse or fine particles. The segregation trend and its relationship to aspect ratio are explained using the monodisperse random packing density and sphericity of the particles.
Article
Engineering, Chemical
Xiaodong Cui, Jianjian Dai, Haotian Xu, Xi Gao
Summary: Understanding the flow behaviors of nonspherical particles is crucial for the design and optimization of rotating drums. In this study, rotating drum experiments were conducted to investigate the flow behavior of particles with different properties. The SuperDEM method was utilized to simulate the flow of both spherical and nonspherical particles and validated by comparing the simulation results with the experimental data. The results showed that particle shape significantly affected the flow behavior, angle of repose, and kinetic energy conversion efficiency.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Lei Xie, Shuyan Wang, Baoli Shao, Xi Chen, Nuo Ding, Yimei Ma
Summary: This paper applies the Discrete Element Method (DEM) to study the radial mixing and segregation of ellipsoidal particles with different densities in a rotating drum. The results show that light particles tend to accumulate at the periphery of the granular bed, while heavy particles concentrate in the center area. Particle shape affects collision probability and strength, and ellipsoidal particles require more energy for movement.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Engineering, Chemical
Nicolin Govender
Summary: This paper utilizes the advances in GPU computing via the Blaze-DEM code to study the effect of particle shape on heat transfer in a rotating drum. The results show that shape irregularity has the greatest impact on heat conduction, with non-symmetric shapes exhibiting better heat transfer performance. Furthermore, there is a linear trend of system temperature with both RPM and fill level.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Mengxiao Yu, Houjun Zhang, Junheng Guo, Jinli Zhang, You Han
Summary: This study utilized the DEM method to investigate the flow behavior of polydisperse particles in a rolling mode rotating drum. By studying particle parameters in different regions, suggestions for improving performance were presented. Difference in flow behavior between polydisperse and monodisperse particles was also highlighted for industrial applications of complex particle systems.
Article
Chemistry, Multidisciplinary
Cesar Martin Venier, Santiago Marquez Damian, Sergio Eduardo Bertone, Gabriel Dario Puccini, Jose Maria Risso, Norberto Marcelo Nigro
Summary: The study compares the performance of discrete and continuum computational models for granular flow dynamics in a rotating drum, finding that the discrete model aligns better with experimental observations while the continuum model accurately predicts the dynamics of the bed in the rolling and cascading regimes.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Chemical
Chuanning Jiang, Xizhong An, Meng Li, Yuhang Wu, Dazhao Gou, Yongli Wu
Summary: The mixing of binary spheres/cylinders in a rotating drum was numerically simulated using the discrete element method (DEM). The effects of various parameters on the mixing quality were studied, and the corresponding mechanisms were analyzed. Results showed that the mixing quality can be effectively improved under rolling/cascading flow regime, but becomes worse under cataracting flow regime. A higher aspect ratio leads to a weaker interlocking effect between particles, smaller porosity, and higher contact efficiency, thus improving the mixing quality. Spherical particles are more conducive to improving the mixing quality compared to cylindrical particles with the same volume.
Review
Chemistry, Multidisciplinary
Franois Mouvet, Justin Villard, Viacheslav Bolnykh, Ursula Rothlisberger
Summary: This article introduces three methods to improve the efficiency of FPMD simulations, including an efficient implementation of FPMD-QM/MM simulations, specially devised multiple-time-step algorithms, and machine learning models. These methods significantly speed up FPMD simulations while preserving real-time dynamics and accuracy.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Food Science & Technology
Kabiru Ayobami Jimoh, Norhashila Hashim, Rosnah Shamsudin, Hasfalina Che Man, Mahirah Jahari, Daniel I. Onwude
Summary: Grain drying plays a crucial role in preparing finished grain products. The kinetics of grain drying is influenced by heat and mass transfer between the grain and the environment. Insufficient, improper, and excessive drying negatively affect grain quality and consumer acceptance. Various drying technologies have been used, such as fluidized bed dryers, infrared dryers, and microwave dryers. Combining different drying technologies and implementing treatments like ultrasound and dehumidification allows for higher moisture removal, shorter processing time, increased energy efficiency, and nutrient retention. This review focuses on the drying conditions, time, energy consumption, nutrient retention, and cost associated with reducing moisture content in grain for further processing and storage.
FOOD ENGINEERING REVIEWS
(2023)
Article
Engineering, Chemical
Nicolin Govender, Rafal Kobylka, Johannes Khinast
Summary: The blending of granular materials with different morphologies in industrial processes is unpredictable. Discrete element method simulations using polyhedral particles were used to study the effect of cohesion and particle shape in a rotating drum. Results showed that symmetric polyhedral shapes had the best mixing, while irregular shapes had the worst. Mixing improved with increasing cohesive particle size. Equipment geometry and rotation speed also significantly affected mixing.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Ran Li, Wenzheng Xiu, Baolin Liu, Gang Zheng, Hui Yang
Summary: Research on the flow of rice particles has shown that it differs from classical spherical particles, often exhibiting multiple velocity peaks. Lowering the rotation speed of the drum can change the flow into an avalanche mode, where particles slide and cover the entire rice particle bed.
Article
Materials Science, Multidisciplinary
Patrick Richard, Riccardo Artoni, Alexandre Valance, Renaud Delannay
Article
Engineering, Chemical
Monica Tirapelle, Andrea C. Santomaso, Patrick Richard, Riccardo Artoni
Summary: This paper experimentally investigates density-difference-driven segregation in a range of density ratios and heavy particle concentrations, proposing a continuum approach to model the process. The model is validated by comparison with experimental findings, successfully predicting density-driven segregation at different density ratios and volumetric fractions.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Education, Scientific Disciplines
Nicolas Plihon, Gauthier Legrand, Francis Pagaud, Arsene Chemin, Jeremy Ferrand, Nicolas Taberlet
Summary: Magnus gliders exhibit spectacular looped trajectories due to the Magnus force, with initial translational velocity and direction having a significant impact on the type of trajectory. Initial backspin has a less significant effect on the trajectory, while both initial translational velocity and backspin influence the maximum height of the trajectory's apex.
AMERICAN JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Marceau Henot, Nicolas Plihon, Nicolas Taberlet
Summary: The formation of glacier tables depends on the size and thermal conductivity of the cap, which can either stand on an ice foot or sink into the ice block. A one-dimensional conduction model shows that the competition between geometrical amplification and heat flux reduction controls the differential ice melting process. Additionally, a dimensionless number identified by the model controls the onset of glacier tables formation.
PHYSICAL REVIEW LETTERS
(2021)
Article
Engineering, Chemical
Pravin R. Badarayani, Riccardo Artoni, Bogdan Cazacliu, Erdin Ibraim, Patrick Richard
Summary: The study investigates the segregation tendency of mixtures containing rigid sand particles and soft rubber particles under vertical taps. Results show that rubber particles tend to migrate towards the bottom of the system when particle sizes are equal, with segregation reduced as the rubber fraction increases and competing with size-induced segregation if rubber chips are larger. Horizontal clustering tendency increases with the number of taps and is reduced by adding water.
Article
Multidisciplinary Sciences
Nicolas Taberlet, Nicolas Plihon
Summary: This article examines the formation of Zen stones on frozen lakes and the subsequent pedestal shape, providing a physical explanation for the process involving slow surface sublimation due to the shade created by the stone. Laboratory experiments confirm that the stone acts as an umbrella, hindering sublimation and protecting the ice beneath, leading to the pedestal formation. Numerical simulations show that the stone's shape influences the ice foot formation, with the stone's infrared radiation leading to the depression surrounding the pedestal.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Mechanics
Patrick Richard, Alexandre Valance, Renaud Delannay, Philippe Boltenhagen
Summary: In this study, extensive simulations using the discrete element method were conducted to investigate the gravity-driven flows of cohesionless granular media over an erodible bed confined between two frictional sidewalls. The focus was on the role of the sidewalls, specifically the gap widths between them. Two distinct regimes were observed, with regime I corresponding to dense flows and regime II exhibiting a strong variation of the volume fraction through the depth. Various flow properties were rescaled using three relevant lengths identified in the system: the gap between sidewalls (W), the length characterizing the vertical variation of the volume fraction (l), and a characteristic length associated with the vertical variation of the streamwise velocity (h). The behavior of l and h differed between regime I and regime II, resulting in differing scaling of flow rate with respect to these lengths.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Antonio Pol, Riccardo Artoni, Patrick Richard, Paulo Ricardo Nunes da Conceicao, Fabio Gabrieli
Summary: The kinematics and shear-induced alignment of elongated particles in confined, heterogeneous flow conditions were experimentally investigated. The results show that the slip velocity at the bottom is influenced by the particle shape, while rotations are highly frustrated by particle shape with more elongated particles showing a lower angular velocity. The proneness of a particle to rotate is observed to be shear-rate dependent, with a stronger inhibition in low shear zones. The average particle orientation is slightly tilted downwards and decreases with particles' elongation. Orientational order increases with particles' elongation and is not affected by the applied confinement, except for a weak decrease in regions of higher shear rate. At the particle-scale, angular velocity fluctuations are strongly correlated with local particle orientation, with particles strongly misaligned with the preferential particles' orientation rotating faster. This correlation becomes stronger for more elongated particles and is almost unaffected by the applied confinement.
NEW JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Pravin Badarayani, Bogdan Cazacliu, Erdin Ibraim, Riccardo Artoni, Patrick Richard
Summary: The number of scrap tires disposed of in piles across the world is increasing, leading to the need for new recycling solutions. This article investigates the one-dimensional loading/unloading behavior of sand-rubber mixtures and proposes a novel criterion for classifying the behavior of the mixture.
APPLIED SCIENCES-BASEL
(2023)
Article
Mechanics
Cheng-Chuan Lin, Riccardo Artoni, Fu-Ling Yang, Patrick Richard
Summary: A steady granular flow experiment was conducted in a confined annular shear cell to investigate the degradation of the wall friction coefficient μ(w) relative to the intrinsic sliding friction coefficient f between grains and the container wall. Two existing models were used to examine the decay trend of μ(w)/f based on the ratio of shear velocity to the square root of granular temperature χ and the ratio of grain angular and slip velocities Ω. A hidden relation between χ and Ω, or equivalently, between granular temperature and grain rotation speed, was speculated and confirmed using experimental data. A unified μ(w)/f - χ model was proposed, which showed general agreement with the measured trend and provided physical interpretations for the model coefficients. Therefore, it is concluded that both fluctuations in grain translations and mean rotation are crucial mechanisms for degrading μ(w)/f.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Fluids & Plasmas
Antonio Pol, Riccardo Artoni, Patrick Richard
Summary: In this work, a scaling law for wall friction weakening in three-dimensional, dense, fully confined granular flows made of shape anisotropic particles is discussed through particle-based simulations. The study reveals that particle shape has limited influence on translational velocity and granular temperature profiles, but significantly affects angular motion. The mobilization of friction at the sidewalls is influenced by both particle shape and flow pattern. The proposed scaling law for wall friction mobilization, based on a balance between sliding and rolling motion, is found to be robust regardless of various system parameters.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Physics, Fluids & Plasmas
Marceau Henot, Vincent J. Langlois, Nicolas Plihon, Nicolas Taberlet
Summary: Dirt cones are meter-scale structures formed by ice cones covered with a layer of debris. We conducted field observations, laboratory experiments, and numerical simulations to understand the formation process. We found that the insulating properties of the debris layer reduce ice melting, leading to differential ablation and the formation of conical shapes. The cones reach a steady state when the insulation compensates for the heat flux. Our findings allowed us to develop a model that accurately reproduces field observations and experimental results.
Article
Physics, Fluids & Plasmas
Riccardo Artoni, Patrick Richard, Michele Larcher, James T. Jenkins
Summary: In this letter, the effects of flow inhomogeneity on self-diffusion behavior in granular flows are discussed. Measurements of self-diffusion coefficients in steady, inhomogeneous, and collisional shearing flows are presented. The results show that a scaling based on the granular temperature is more effective in describing the self-diffusion behavior. These findings lay the groundwork for diffusion models in inhomogeneous shearing flows, which are important for understanding mixing and segregation.
Article
Chemistry, Physical
Riccardo Artoni, Michele Larcher, James T. Jenkins, Patrick Richard
Summary: This study reports measurements of self-diffusion coefficients in collisional shearing flows of frictional, inelastic spheres, highlighting the impact of solid volume fractions on diffusivity. Comparison with empirical scaling and kinetic theory predictions reveals discrepancies, suggesting the need for further investigation into the diffusion behavior of such systems.
Article
Physics, Fluids & Plasmas
Jeremy Sautel, Charles-Edouard Lecomte, Nicolas Taberlet
Summary: This paper explores size segregation in a two-dimensional assembly of grains in a circular geometry under periodic perturbations, finding that radial segregation occurs not only on the surface but also in the core of an asteroid. The study also examines the characteristic time and efficiency of the segregation mechanism as various parameters such as perturbation intensity, frictional properties, and rotational freedom of grains are changed.
Article
Chemistry, Physical
Yiping Yin, Zhe Wang, Hua Zou
Summary: This study presents a novel method for preparing dimpled polymer-silica nanocomposite particles using interfacial swelling-based seeded polymerization. The optimized conditions allow for a relatively high percentage of dimpled particles to be achieved.
Article
Chemistry, Physical
Brenden D. Hoehn, Elizabeth A. Kellstedt, Marc A. Hillmyer
Summary: Porous materials with nanometer-scale pores have important applications as nanoporous membranes. In this study, ABA triblock copolymers were used as precursors to produce nanoporous polymeric membranes (NPMs) in thin film form by degrading the end blocks. Polycyclooctene (PCOE) NPMs with tunable pore sizes were successfully prepared using solvent casting technique. Oxygen plasma etching was employed to improve the surface porosity and hydrophilicity of the membranes. This study provides a straightforward method to produce tough NPMs with high porosity and hydrophilic surface properties.
Article
Chemistry, Physical
Vladislav S. Petrovskii, Stepan I. Zholudev, Igor I. Potemkin
Summary: This article investigates the behavior of linear and ring polypeptide chains in aqueous solution and explores the properties of the complexes formed by these chains with oppositely charged surfactants. The results demonstrate that the complexes of linear supercharged unfolded polypeptides and the corresponding surfactants exhibit impressive adhesive properties.
Article
Chemistry, Physical
Merve Cevik, Serkan Dikici
Summary: Cardiovascular diseases are a leading cause of death globally, and vascular grafts are a promising treatment option. This study focuses on tissue-engineered vascular grafts (TEVGs) using decellularized parsley stems as a potential biomaterial. The decellularized parsley stems showed suitable properties for TEVGs, providing a suitable environment for human endothelial cells to form a pseudo endothelium. This study showcases the potential of using parsley stems for TEVGs.
Article
Chemistry, Physical
Gustavo A. Vasquez-Montoya, Tadej Emersic, Noe Atzin, Antonio Tavera-Vazquez, Ali Mozaffari, Rui Zhang, Orlando Guzman, Alexey Snezhko, Paul F. Nealey, Juan J. de Pablo
Summary: The optical properties of liquid crystals are typically controlled by electric fields. In this study, we investigate the effects of microfluidic flows and acoustic fields on the molecular orientation and optical response of nematic liquid crystals. We identify several previously unknown structures and explain them through calculations and simulations. These findings hold promise for the development of new systems combining sound, flow, and confinement.
Article
Chemistry, Physical
Xinjun Wu, Xin Guan, Shushu Chen, Jiangpeng Jia, Chongyi Chen, Jiawei Zhang, Chuanzhuang Zhao
Summary: This research presents a novel shape memory hydrogel with a remodelable permanent shape and programmable cold-induced shape recovery behavior. The hydrogel is prepared using specific treatment methods to achieve shape fixation by heating and shape recovery by cooling. Additionally, deformable devices can be obtained by assembling hydrogel blocks with different concentrations.
Article
Chemistry, Physical
Rebecca Hengsbach, Gerhard Fink, Ulrich Simon
Summary: This study examines the properties of DNA functionalized pNipmam microgels and pure pNipmam microgels at different concentrations of sodium chloride and in PBS solutions using temperature dependent H-1-NMR measurements. The results show that DNA modification affects the volume phase transition temperature and the addition of salt and PBS further enhances this effect.
Article
Chemistry, Physical
Ningyi Li, Junhong Li, Lijingting Qing, Shicheng Ma, Yao Li, Baohui Li
Summary: This paper investigates the self-assembly behavior of colloids with competing interactions under spherical confinement and finds that different ordered structures can be formed under different sized spherical confinements. Moreover, more perforated structures are formed in smaller spheres.
