Article
Physics, Multidisciplinary
Matthew Macaulay, Pierre Rognon
Summary: This study examines the distribution of contact forces in dense granular flows and finds that higher magnitude contact forces exist in faster flows with stiffer grains. A proposed physical mechanism explains this rate-dependent force transmission, establishing a relationship between contact forces and grain velocities. This analysis provides a starting point for unifying a range of continuum models based on either contact forces or grain velocities.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Farnaz Fazelpour, Karen E. Daniels
Summary: In this paper, the influence of boundary shape, particularly roughness, on wall slip in dense granular flows is investigated. Experiments are conducted on a quasi-2D annular shear cell to examine the influence of different boundary properties. It is found that the full flow profile can be accurately captured using a single set of model parameters, with the wall slip velocity set by direct observation. The measurements also reveal a universal relationship between dimensionless fluidity and velocity.
Article
Engineering, Chemical
T. M. Povall, I Govender, A. T. McBride
Summary: A novel 3D measurement method was proposed to test the compressibility and isotropy of rotating drum flows using the DEM with mu(I) rheology. The study found that compressibility enhances isotropy and statistically better fits were obtained when using an empirically-derived friction law. However, all models failed to capture behavior at very low inertial numbers.
Article
Physics, Multidisciplinary
Kuniyasu Saitoh, Takeshi Kawasaki
Summary: We investigated the characteristics of two-dimensional dense granular flows using molecular dynamics simulations. Our results show that the shear-induced diffusion of granular particles exhibits different behaviors at different time scales, and is also influenced by the contact damping model.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Physical
Farnaz Fazelpour, Zhu Tang, Karen E. Daniels
Summary: In this paper, the authors conducted experiments to investigate the influence of particle properties on the model parameters used in the nonlocal rheology. They found that different particle shapes and materials have significant effects on the nonlocal parameter, indicating the dominance of geometric friction over material friction.
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
Physics, Multidisciplinary
Hugo Perrin, Matthieu Wyart, Bloen Metzger, Yoel Forterre
Summary: The study found that thin frictionless granular layers lack hysteresis in avalanche angle, but stability increases as the layer gets thinner. Steady rheological laws obtained for different layer thicknesses can be collapsed into a unique master curve, supporting the idea that nonlocal effects are a consequence of typical finite-size effects associated with the presence of a critical point.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
M. Reza Shaebani, Janos Torok, Maniya Maleki, Mahnoush Madani, Matt Harrington, Allyson Rice, Wolfgang Losert
Summary: The research found that the flow profile is independent of gravity for geometries with a free top surface; however, under a confining pressure or if the sheared layer withstands the weight of the upper layers, increasing gravity promotes the transition from closed shear zones to open ones. The center position and width of the shear zone, as well as the axial angular velocity at the top surface, follow universal scaling laws.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Kasra Farain, Daniel Bonn
Summary: The question of when dense granular materials start to flow under stress has not been resolved. A simple equation based on frictional aging of the granular packing is developed and tested, resulting in a nonmonotonic stress-strain relation independent of shear rate. This relation helps understand the quasistatic deformations and solid-to-liquid transition of aging granular media. It also explains the flow history dependence of mechanical properties and sensitivity to initial preparation of granular media.
PHYSICAL REVIEW LETTERS
(2023)
Article
Mechanics
Peter Varun Dsouza, Prabhu R. Nott
Summary: Granular materials exhibit unique features such as dilatancy and large-scale secondary flow driven by a combination of shear and gravity. The height at which the material is filled in a primary flow determines both the shape of the shearing region and the form of the secondary flow, indicating a close coupling between the two phenomena. Unlike fluid instabilities driven by inertia, the secondary flow in granular materials occurs at low shear rates and is an integral part of the kinematic response.
JOURNAL OF FLUID MECHANICS
(2021)
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
Computer Science, Interdisciplinary Applications
Francois Bouchut, Enrique D. Fernandez-Nieto, El Hadji Kone, Anne Mangeney, Gladys Narbona-Reina
Summary: This study investigates the dilatancy effects in dry granular flows, revealing that initial volume fraction affects the height of deposits but has little impact on the front position and deposit shape. The model predicts increasing dilation of the mass with increasing slopes, indicating the key role of dilatancy in describing granular flows.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Mechanics
Ishan Srivastava, Leonardo E. Silbert, Gary S. Grest, Jeremy B. Lechman
Summary: This study investigates the flow of dense granular materials under external shear stress and pressure using discrete element method simulations, proposing a rheological model to describe the two types of flow. The simulations show viscometric behavior with non-negligible first and second normal stress differences, highlighting the role of contact fabric tensor and strain rate tensor in determining normal stress differences.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
X. Cui
Summary: This paper discusses the generation of strong oblique shock waves in laboratory experiments and numerical simulations. It investigates the formation of strong oblique shock waves and their steady-state solutions, as well as the interaction between weak and strong oblique shocks in both experiments and simulations.
Article
Physics, Multidisciplinary
Seongmin Kim, Ken Kamrin
Summary: We propose a constitutive equation for three-dimensional granular flows based on discrete element method simulations. By considering second-order Rivlin-Ericksen tensors, we extend an existing granular temperature-sensitive rheological model to capture non-local phenomena, normal stress differences, and secondary flows. Three model parameters are calibrated using the inertial number and a dimensionless granular temperature. The model is validated through finite difference method simulations of inclined chute flows, successfully predicting the velocity and stress fields, including previously unaccounted for secondary vortical flows and slow creeping zones.
FRONTIERS IN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Riccardo Artoni, Aurelien Neveu, Yannick Descantes, Patrick Richard
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2019)
Article
Engineering, Chemical
Riccardo Artoni, Giovanni Loro, Patrick Richard, Fabio Gabrieli, Andrea C. Santomaso
Article
Engineering, Chemical
Monica Tirapelle, Andrea C. Santomaso, Colin Hare
Article
Engineering, Environmental
F. Sessa, K. F. Veeyee, P. Canu
Summary: The study explored the conversion of industrial waste from local tropical hardwoods in Cameroon to biochar, with pyrolysis temperature being the most crucial factor affecting biochar yield and quality.
Article
Engineering, Environmental
L. Da Lio, P. Castello, G. Gianfelice, R. Cavalli, P. Canu
Summary: The key issue in horse manure combustion is the high moisture content, as demonstrated through ignition tests. Improving moisture removal efficiency is crucial for effective energy recovery. This study disproved the notion that manure combustion requires the addition of auxiliary fuel like wood shavings.
Article
Chemistry, Physical
Jaime Moreno-Juez, Luis Marcelo Tavares, Riccardo Artoni, Rodrigo M. de Carvalho, Emerson Reikdal da Cunha, Bogdan Cazacliu
Summary: This study investigated the attrition of aggregates during concrete mixing through experiments and simulations. Results showed that higher impeller speeds, co-current operation, and wet aggregate led to increased mass loss. Mixing of agglomerates in the concrete mix reduced attrition significantly compared to mixing aggregates alone.
Article
Energy & Fuels
G. Gianfelice, P. Canu
Summary: This study explores the chemical and physical processes within a single wood pellet to improve the design of wood pellet stoves and boilers, revealing that the conversion rate is controlled by heat conduction and is linearly proportional to the surrounding temperature. It also found that at higher combustion temperatures, the char yield decreases and useful heat must be extracted from volatiles combustion.
Article
Engineering, Chemical
Matthieu Constant, Nathan Coppin, Frederic Dubois, Riccardo Artoni, Jonathan Lambrechts, Vincent Legat
Summary: This paper investigates the density sorting of grains using water jigging by conducting experiments and comparing numerical results for two initial bed configurations. The vertical composition of the deposit is estimated after different numbers of water pulses to show the sorting evolution over time. Key parameters are varied numerically to determine the sensitivity of the process.
Article
Energy & Fuels
F. Sessa, G. Merlin, P. Canu
Summary: The exploitation of pine bark for production of biochar or activated carbons is influenced by the maximum temperature. Chemical activation of activated carbons has shown significant effectiveness in VOC capture, with the one activated by K2CO3 showing the highest loading capacity.
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
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
Green & Sustainable Science & Technology
Glaydson S. Dos Reis, Bogdan Cazacliu, Riccardo Artoni, Jean-Michel Torrenti, Carlos S. Hoffmann, Eder C. Lima
Summary: Accelerated carbonation method was applied to improve the CO2 storage ability of recycled aggregates through rolling carbonation process. Tests showed that rotating carbonation significantly increased carbonation kinetics compared to static carbonation, with up to 80 mg/g of CO2 sequestered. The optimal conditions for efficient carbonation were found to be 100 rpm rotation speed, 8% aggregate moisture content, and 500 g of aggregates in a 5 L reactor.
CLEANER ENGINEERING AND TECHNOLOGY
(2021)
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
S. Volpato, M. Tirapelle, A. C. Santomaso
Article
Engineering, Chemical
Qing Han, Mengqing Shi, Linkai Han, Di Liu, Mingwei Tong, Yuxin Xie, Zhonghua Xiang
Summary: Developing highly efficient bifunctional oxygen electrocatalysts is crucial for zinc-air flow batteries. Metal-organic frameworks (MOFs) and covalent organic polymers (COPs) have emerged as promising alternatives due to their designable and controllable atomic-level structures. However, their catalytic performances are limited by conductivity and catalytic activity. In this study, nanosheet FeNi-MOF and iron phthalocyanine rich COP hybrid materials are assembled through the pi-pi stacking effect to create highly efficient bifunctional electrocatalysts. The resulting catalyst exhibits superior catalytic performance and stability, making it a promising candidate for zinc-air flow batteries.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Daria Grigorash, Dmytro Mihrin, Rene Wugt Larsen, Erling H. Stenby, Wei Yan
Summary: The article introduces a new approach to describe the cross-association between molecules, allowing for the simulation of weakly bound molecular complexes with different conformations in mixtures. By incorporating this approach into the equation of state, accurate predictions of vapor-liquid equilibrium and liquid-liquid equilibrium can be made. The new method is validated through experiments on alcohol and acid mixtures, with the results compared to experimental data, demonstrating its accuracy and reliability.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Mohammed Al-Sharabi, Daniel Markl, Vincenzino Vivacqua, Prince Bawuah, Natalie Maclean, Andrew P. E. York, Axel Zeitler
Summary: This study used terahertz pulsed imaging to investigate the transport process of different solvents into ceramic catalytic materials. The results showed that the heating rate of the samples influenced the water transport rate, while the viscosity of 1-octanol slowed down its transport.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chukwunonso Anyaoku, Sati Bhattacharya, Rajarathinam Parthasarathy
Summary: This study aimed to enhance understanding of settling dynamics in viscoelastic fluids by developing a semi-empirical correlation and a dimensionless ratio, which accurately described the characteristics of settling suspensions.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Antti I. Koponen, Janika Viitala, Atsushi Tanaka, Baranivignesh Prakash, Olli-Ville Laukkanen, Ari Jasberg
Summary: This study focuses on the development of foam application chemicals for the paper and board industry. The research explores the rheology of the polyvinyl alcohol foam used in the process. Measurements were conducted to determine the foam viscosity and slip flow. The results suggest that slip flow contributes significantly to the total flow rate, and the obtained viscosity and slip models provide a solid foundation for industrial processes.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Dalei Sun, Jinghui Cai, Yating Yang, Zhiwu Liang
Summary: In this study, Fe-doped alpha-Bi2O3 catalysts with different Fe/Bi molar ratios were synthesized and utilized in the carbonylation of isobutyl amine with CO2. The results showed that Fe doping significantly enhanced the catalytic abilities of alpha-Bi2O3.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Yuan Tian, Xinxin Wang, Yanrong Liu, Wenping Hu
Summary: This paper predicts the solubility of nitrogen gas in ionic liquids (ILs) using two quantitative structure-property relationship (QSPR) models. By combining machine learning methods and ionic fragments contribution method, the accuracy and reliability of the prediction models are improved.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Liwang Wang, Wei Liu, Pan Yang, Yulong Chang, Xiaoxu Duan, Lingyu Xiao, Yaoming Hu, Jiwei Wu, Liang Ma, Hualin Wang
Summary: This study investigates the effective phase interfacial area (ae) of hydro-jet cyclones at different injection angles. The results show that a 45 degrees upward incidence angle yields the most favorable flow field characteristics for efficient mass transfer. The significant enhancement in ae of the hydro-jet cyclones offers the advantage of reducing equipment volume and cost savings.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chuanjun Wu, Jiangzhi Chen, Jiyue Sun, I-Ming Chou, Shenghua Mei, Juezhi Lin, Lei Jiang
Summary: In this study, the solubility of H2S hydrate in water was measured using Raman spectroscopy. The results showed that the solubility increases with temperature under certain equilibrium conditions, and the solubility also depends on pressure and temperature under different equilibrium conditions. A thermodynamic model based on the van der Waals-Platteeuw theory was developed to predict the solubility, demonstrating its accuracy.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Lorenzo Brivio, Serena Meini, Mattia Sponchioni, Davide Moscatelli
Summary: This study investigates the influence of three main parameters and proposes a kinetic model to predict the optimal operating conditions for high yield of dimethyl terephthalate (DMT) in the chemical recycling process of polyethylene terephthalate (PET).
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Hongju Lin, Fanhui Liao, Yanchang Chu, Mingyu Xie, Lun Pan, Yuanyuan Wang, Lijian Leng, Donghai Xu, Le Yang, Gangfeng Ouyang
Summary: A honeycomb NiCo/C-Na catalyst with a micro-meso-macroporous structure has been fabricated and shown to have significantly higher catalytic activity for the decarboxylation of fatty acids. It also proves to be efficient in upgrading sludge HTL bio-crude, resulting in a biofuel with decreased viscosity and increased density.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Xiaoxian Li, Rui Li, Min Lin, Mingde Yang, Yulong Wu
Summary: A series of coated non-noble metal porous carbon catalysts were synthesized and applied to the aqueous-phase deoxygenation of algal bio-oil. One of the catalysts showed excellent deoxygenation selectivity and catalytic activity at 250 degrees C. The catalyst exhibited good hydrothermal stability and the reaction mechanism was proposed based on product analysis and active site analysis.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
M. V. Chudakova, M. V. Popov, P. A. Korovchenko, E. O. Pentsak, A. R. Latypova, P. B. Kurmashov, A. A. Pimenov, E. A. Tsilimbaeva, I. S. Levin, A. G. Bannov, A. V. Kleymenov
Summary: A series of catalysts with different potassium contents were prepared using solution combustion synthesis and characterized using various techniques. The results showed that the potassium content affected the phase composition and texture of the catalysts. The addition of a small amount of potassium resulted in a change in particle size distribution, leading to higher hydrogen yield. The Ni-1%K2O/Al2O3 catalyst exhibited the highest hydrogen yield at temperatures of 675 and 750 degrees Celsius.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Aliakbar Roosta, Nima Rezaei
Summary: In this study, we modified the electrolyte cubic plus association equation of state (e-CPA EoS) and integrated it with two electrical conductivity models to estimate the electrical conductivity of 11 monovalent electrolyte solutions in water. The modified e-CPA model demonstrated better performance and the hybridization with electrical conductivity models resulted in two predictive models for estimating the electrical conduction of dilute and concentrated electrolyte solutions. These predictive models showed relative average percentage deviations (AARD) of 11.15% and 13.87% over wide ranges of temperature and electrolyte concentration.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Haoren Niu, Jianzheng Wang, Qingzhu Jia, Qiang Wang, Jin Zhao, Fangyou Yan
Summary: A study developed two quantitative structure-property relationship models for the complexation performance of alpha- and beta-cyclodextrins and validated their stability and predictive ability through internal and external validation. The models showed robustness and satisfactory performance, as demonstrated by the experimental results and model validations. These models can effectively predict the binding constants between cyclodextrins and various types of molecules, providing valuable tools for cyclodextrin design.
CHEMICAL ENGINEERING SCIENCE
(2024)
