Article
Engineering, Chemical
Marv J. Khala, Colin Hare, Chuan-Yu Wu, Navin Venugopal, Martin J. Murtagh, Tim Freeman
Summary: The study investigates mixing and segregation of binary mixtures of glass beads and/or resin particles based on density and size differences using a new FT4 methodology. Results show that the mixing index increases with density and size ratio, with flow energy and torque variation related to mixture components' mixing and segregation. DEM numerical analysis reveals that mixing and segregation occur differently in non-cohesive and cohesive systems under various stress conditions.
Review
Engineering, Chemical
Corne J. Coetzee, Otto C. Scheffler
Summary: This paper discusses the application of the discrete element method (DEM) in simulating the behavior of granular materials, focusing on contact models for cohesive materials. It also critically reviews parameter calibration methods for cohesive materials. This provides engineers and researchers with a reference for selecting suitable models and calibration methods for their specific applications.
Article
Engineering, Chemical
Takeru Yano, Shuji Ohsaki, Hideya Nakamura, Satoru Watano
Summary: The study found that an increase in particle size ratio can reduce void fraction even in the presence of cohesive particles. Cohesive force decreases contact number, especially between coarse particles.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Engineering, Manufacturing
Daniel Schiochet Nasato, Heiko Briesen, Thorsten Poeschel
Summary: The study evaluated the effect of vibrations applied to the recoating mechanism on the quality of the powder bed, finding that small frequency and amplitude can reduce the porosity of the granular bed, while large frequency and amplitude can lead to a vibro-fluidized state.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Chemical
Daniel Schulz, Nadja Woschny, Eberhard Schmidt, Harald Kruggel-Emden
Summary: This study investigates the detachment of fine adhered dust particles during bulk particle contacts using an adhesive Discrete Element Method (DEM). The research introduces dust detachment functions in a non-adhesive DEM, which track only the coarse carrier particles as a composed bulk particle. The implemented detachment functions, including normal and tangential lift-off conditions, as well as a rotational condition, are benchmarked based on dust-resolved adhesive DEM simulations.
Article
Materials Science, Composites
Jagan Selvaraj, Luiz F. Kawashita, Mehdi Yasaee, Gordon Kalwak, Stephen R. Hallett
Summary: A novel cohesive element formulation is proposed for modelling composite delamination, offering increased stability and requiring fewer elements. This new formulation combines nodal rotations and multiple integration points to improve the accuracy of delamination propagation simulation.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Ceramics
Farid Asadi, Damien Andre, Sacha Emam, Pascal Doumalin, Marc Huger
Summary: In the steelmaking industry, the refractory ceramics used in ladles are found to have improved thermal shock resistance when pre-existing microcracks are present. The Discrete Element Method (DEM) is a suitable numerical approach for modeling the quasi-brittle behavior of these ceramics with microcracks. By introducing initial well-distributed damages following a Weibull distribution, the study aims to investigate the effect of microcracks on the quasi-brittle behavior of a numerical sample under uniaxial and cyclic tensile tests. Ultimately, a quantitative DEM model for simulating such a complex behavior is proposed.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Engineering, Chemical
T. Kronlachner, S. Pirker, T. Lichtenegger
Summary: Simulating highly cohesive powders based on discrete element requires significant coarse-graining and calibration experiments. In this study, we determine the material parameters for highly and mildly cohesive metal powders in a low-consolidated state to replicate rotating-drum experiments accurately. By making slight adjustments to rolling friction, the standard discrete element models can successfully capture the dynamics, especially of highly cohesive powders. Additionally, we demonstrate that using less informative characterization methods for optimization may result in multiple combinations of contact parameters, while block analysis provides a well-defined solution.
Article
Agronomy
Guichuan Li, Haiyu Li, Xuan Li, Zhichao Gong, Qinghua Yang, Yuxiang Huang, Zuoli Fu
Summary: This study obtained an accurate buckwheat seed model by calibrating the discrete element simulation parameters and established buckwheat seed particle models based on manual and automatic filling methods. The simulation results were verified through static cylinder-lifting and dynamic seed-metering tests. The automatic filling 36-sphere particle model showed higher accuracy compared to the manual filling 7-sphere particle model. The buckwheat seed particle model developed in this study will support the design of buckwheat special seed-metering devices and improve the quality of buckwheat mechanized sowing operation.
Article
Engineering, Chemical
Behrooz Jadidi, Mohammadreza Ebrahimi, Farhad Ein-Mozaffari, Ali Lohi
Summary: Non-spherical particles have a lower mixing quality compared to spherical particles in a twin paddle blender. Cubical particles show the highest compactness in the solid mixture. Non-spherical particles exhibit a higher resistance to movement. The diffusion mechanism is superior in mixing, with shear and normal stresses peaking near the blade tips.
Article
Engineering, Chemical
Mohammadreza Ebrahimi, Amirsalar Yaraghi, Behrooz Jadidi, Farhad Ein-Mozaffari, Ali Lohi
Summary: This study investigated the mixing of bi-disperse particles in a horizontal paddle mixer using sampling experimental techniques and DEM, showing a significant influence of operating parameters on mixing quality, with r(n) having the most significant effect. The results suggest that diffusion mechanism is dominant over convection mechanism in achieving the best mixing performance.
Article
Engineering, Chemical
Zhen Wan, Youjun Lu
Summary: This paper investigates the local and global mixing and segregation characteristics of binary mixtures in a gas-solid fluidized bed using a computational fluid dynamics-discrete element method (CFD-DEM) coupled approach. A methodology based on solids mixing entropy is developed to quantify the mixing degree and time of the bed. The effects of gas velocity, particle density ratio, and size ratio on mixing/segregation behavior are discussed. The results show that increasing gas velocity promotes the mixing of binary mixtures, while increasing particle density ratio and size ratio lead to greater segregation and reduced mixing degree.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Francisco J. Canamero, Anand R. Doraisingam, Marta Alvarez-Leal
Summary: This article introduces a DIY approach for the production of customized fast moving consumer goods, including powder detergent. A machine connected to a digital platform is used to manufacture a customized detergent according to the clients' needs. The mixing process of the powder detergent is modeled using the discrete element method, and the performance is studied considering the allowable mass fraction range of each component and a mixer speed of 45 rpm. A machine learning algorithm is then employed to predict the mixing index using the dataset generated from this study. The developed model accurately predicts the mixing index in advance.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Chemical
J. M. Tiscar, D. Llorens, G. Mallol, J. Boix, J. A. Perez, F. A. Gilabert
Summary: This paper presents a DEM-based modelling framework for simulating the spray-dried powder rheology in the ceramic tiles industry. Through validation, the framework is proven to be an effective tool for designing and optimizing spray-dried powder handling equipment.
Article
Engineering, Aerospace
Mengxue Li, Dewei Tang, Qiquan Quan, Zhijun Zhao, Fan Guo, Linzhi Meng, Zongquan Deng
Summary: This study establishes a numerical model based on the circular arc failure surface hypothesis to predict the ultimate uplift capacity of the anchor rod of anchoring devices during asteroid exploration. The model accuracy is improved through DEM simulation and calibration tests, with results showing a high level of prediction accuracy.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.