Review
Engineering, Chemical
Alberto Di Renzo, Erasmo S. Napolitano, Francesco P. Di Maio
Summary: In the past decade, the application of CFD-DEM for fluidized beds has expanded from small, lab-scale units to larger scale systems, benefiting greatly from coarse graining methods. By introducing coarse graining procedures based on different physical backgrounds, the number of particles that can be simulated has increased, covering pilot-scale and industrially relevant systems. The review discusses scaling for contact forces, hydrodynamic forces, and cohesive forces, quantifying computational savings in terms of coarse graining degree and presenting recent applications and future directions in the field.
Article
Engineering, Environmental
Motoaki Saruwatari, Hideya Nakamura
Summary: The modified coarse-grained method for granular shear flow (M-CGSF) proposed a new coarse-graining method to simulate particle behavior and heat transfer in a rotary kiln reactor. Verification tests confirmed the effectiveness of M-CGSF in coarse-grained DEM simulations with conductive heat transfer in a rotary kiln, showcasing its potential for manufacturing scale simulations.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Chemical
Junwu Wang, Peng Zhao, Bidan Zhao
Summary: The study has shown that the current drag correlations underestimate the effective interphase drag force, and the force exerted on a single particle varies significantly even in statistically homogeneous systems. Although the stochastic CFD-DEM method can provide minor improvements, it is still insufficient to bridge the gap between PR-DNS and CFD-DEM simulations, indicating the need for further research and development of a more accurate drag model.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Construction & Building Technology
Manman Liu, Fangtong Wang
Summary: Aggregate crushing significantly affects the stress-strain curve, compressive strength, and failure mode of concrete. Crushing of coarse aggregates reduces the peak stress and strain of concrete, with a larger impact on normal concrete compared to high-strength concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Pharmacology & Pharmacy
Xiaoyu Liu, Mostafa Sulaiman, Jari Kolehmainen, Ali Ozel, Sankaran Sundaresan
Summary: This study evaluated the effectiveness of two coarse-grained CFD-DEM approaches in drug delivery via dry powder inhalers, finding that the representative particle approach can approximate CFD-DEM results with reasonable accuracies.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2021)
Article
Engineering, Multidisciplinary
Bin Zhang, Yiming Huang, Tingting Zhao
Summary: This paper analyzed existing coarse graining techniques, proposed correct scaling rules, and tested the accuracy of the coarse graining system through multiple simulations. The results show that scaling rules based on exact scaling laws are effective.
CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES
(2021)
Article
Mathematics, Interdisciplinary Applications
Moris Kalderon, Edward Smith, Catherine O'Sullivan
Summary: The discrete element method (DEM) is a well-established approach for studying granular materials in various fields of application, where each granular particle is modeled individually. Different coarse-graining methods have been proposed and reviewed in this work, with two novel porosity coarse-graining strategies being introduced and compared with existing methods. These methods are validated for accuracy and computational cost, providing users with options to adjust between accuracy and computational time.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Article
Engineering, Chemical
Hanqiao Che, Catherine O'Sullivan, Adnan Sufian, Edward R. Smith
Summary: This study introduces a new method using a two-grid coarse-graining approach to determine local porosity for particles, which can more accurately predict fluid-particle interactive force for polydisperse particle systems compared to alternative methods in unresolved CFD-DEM codes.
Article
Engineering, Chemical
Erasmo S. Napolitano, Alberto Di Renzo, Francesco P. Di Maio
Summary: The design, scale-up and operation of cyclone gas-solid separators are mostly based on simplified models and experience, but previous simulations are not applicable for high-load operations with large particles. The use of DEM-CFD simulations allows for four-way coupled dense flow but is computationally expensive. Coarse-graining methods have been proposed to reduce the computational cost, but more research is needed to understand the trade-off between accuracy and speed-up. This study investigates a coarse-grain DEM-CFD approach for simulating two-phase flow in a cyclone and finds that while macroscopic quantities are maintained, detailed features of the gas and solids flow are affected by the level of coarse graining.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Engineering, Chemical
V. Brandt, J. Grabowski, N. Jurtz, M. Kraume, H. Kruggel-Emden
Summary: DEM-CFD is computationally demanding and limited to lab-scale systems, so coarse-graining approaches are used to summarize particles. This study compares force scaling models in different beds to eliminate influences and identifies optimal scaling rules based on physical parameters. It also analyzes fluidized beds to determine the suitability of scaling models for systems governed by both contact and hydrodynamic forces, providing recommendations for future simulations of industrial-scale particle systems.
Article
Engineering, Chemical
Suranita Kanjilal, Simon Schneiderbauer
Summary: The study focuses on numerical modeling of mixing and transport of lumpy materials using the discrete element method (DEM). By introducing a variable coarse grain ratio, faster computation can be achieved compared to traditional coarse graining, providing more flexibility in reducing the number of particles. Implementation of a correction parameter to address the violation of geometrical similarity resulted from this method leads to fairly good agreement between the revision model, reference DEM simulations, and experimental data.
Article
Engineering, Chemical
Hanqiao Che, Dominik Werner, Jonathan Seville, Tzany Kokalova Wheldon, Kit Windows-Yule
Summary: Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) is a commonly used numerical method for gas-solid flow modeling. Coarse-graining (CG) approaches can reduce the number of particles while maintaining system dynamics. This paper evaluates three typical CG methods for simulating a bubbling fluidized bed and finds that the CG simulation fails when the size ratio between the chamber and particles decreases to approximately 20. It also shows that the specific CG approach for interparticle contact parameters does not substantially affect the simulation results across a wide range of CG factors.
Article
Engineering, Chemical
Xiaomeng Xu, Cheng Li, Xi Gao
Summary: This study adopted the coarse-grained discrete element model (CG-DEM)-computational fluid dynamics (CFD) technology and simplified the mathematical modeling to accurately simulate the fluidization behavior of irregular shape sand particles. The application of a rolling friction model improved the simulation accuracy of the fluidization behavior of sand particles.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Juan Chen, Tien-Fu Lu, Dylan Peukert, Peter Dowd
Summary: This paper presents a numerical study of copper ore tracking through a coarse ore stockpile. The results show that the stockpile model is not sensitive to variables such as the ore size distribution, ore size range, and RFID tag size, while wall friction, stockpile feed belt speed, segregation in the ore flow region, and contact model have a significant effect on ore blending within the stockpile. It was found that the overall performance of RFID-based ore tracking through the stockpile is poor.
Article
Polymer Science
Kevin R. Hinkle
Summary: Molecular dynamics simulations were used to verify the accuracy of using coarse-grained models to describe diblock-arm star polymers. The results showed agreement with atomistic models, reproduced general trends, and investigated structure-property relationships by varying arm number and length. This work is an important first step towards improved design of polymeric nanoparticles for drug delivery applications.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Engineering, Chemical
Tony Rosemann, Simon R. Reinecke, Harald Kruggel-Emden
Summary: Particle-resolved direct numerical simulations were conducted to investigate the impact of particle mobility on fluid flow. The study found that existing correlations for static particle systems are limited in predicting drag and lift forces accurately in dynamic particle-gas flows, with drift forces perpendicular to drag playing a significant role.
CHEMIE INGENIEUR TECHNIK
(2021)
Article
Engineering, Chemical
Darius Markauskas, Stefan Platzk, Harald Kruggel-Emden
Summary: This study numerically analyzes the pneumatic conveying of flexible biomass particles and investigates the relevant factors in gas flow. The results demonstrate that the particle stiffness, bond damping, mass flow rate, length, and gas inflow velocity significantly affect the particle trajectories and pressure drop.
Article
Chemistry, Physical
Shoya Mohseni-Mofidi, Eric Drescher, Harald Kruggel-Emden, Matthias Teschner, Claas Bierwisch
Summary: This paper proposes a methodology to numerically investigate erosion behavior of ductile materials and develops a new contact model. The numerical predictions of erosion are compared with experiments, showing accurate prediction of erosion behavior as a function of impact angle. Using this methodology, the effect of solid particle shapes is studied and conclusions are drawn.
Article
Automation & Control Systems
Jakob Thumm, Marcel Reith-Braun, Florian Pfaff, Uwe D. Hanebeck, Merle Flitter, Georg Maier, Robin Gruna, Thomas Laengle, Albert Bauer, Harald Kruggel-Emden
Summary: This article proposes two neural network experts to improve the prediction accuracy in complex fast-changing sorting scenarios through data-driven approaches. A mixture of experts' method that combines neural networks with hand-crafted motion models is introduced to handle various particle types. The new method not only improves the prediction accuracy for bulk material, but also demonstrates adaptability and robustness to new particle types.
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
(2022)
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
Chemistry, Physical
Bastien Dietemann, Larissa Wahl, Nahum Travitzky, Harald Kruggel-Emden, Torsten Kraft, Claas Bierwisch
Summary: This study focuses on the fabrication of ceramic parts using an additive manufacturing process called robocasting. The research finds that the reorientation of suspended particles during the drying process in robocasting is relatively small and can be neglected in analytical orientation prediction models.
Article
Geochemistry & Geophysics
Martin Weers, Leonard Hansen, Daniel Schulz, Bernd Benker, Annett Wollmann, Carsten Kykal, Harald Kruggel-Emden, Alfred P. Weber
Summary: The separation characteristics of deflector wheel classifiers are not fully understood and existing models fail to accurately predict them. This study developed a model that critically examined common assumptions, such as ideal airflow, neglecting particle interactions, and particle sphericity. By studying airflow, particle shape, particle-particle interactions, and interactions between particles and the deflector wheel, the separation behavior was successfully estimated.
Article
Engineering, Chemical
Albert Bauer, Georg Maier, Marcel Reith-Braun, Harald Kruggel-Emden, Florian Pfaff, Robin Gruna, Uwe Hanebeck, Thomas Laengle
Summary: A DEM-CFD model of an optical belt sorter was compared extensively with experiments, and the model's accuracy was evaluated. The results showed that the numerical model could reproduce the experimental results with high accuracy.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Engineering, Chemical
Albert Bauer, Georg Maier, Marcel Reith-Braun, Harald Kruggel-Emden, Florian Pfaff, Robin Gruna, Uwe Hanebeck, Thomas Laengle
Summary: By modifying the DEM-CFD model of an optical belt sorter to adapt to varying belt speeds, the study shows that optimized sorting setups can achieve promising sorting results at different conveyor belt velocities.
Article
Engineering, Chemical
Daniel Schulz, Simon R. Reinecke, Nadja Woschny, Eberhard Schmidt, Harald Kruggel-Emden
Summary: Dust detachment from bulk solids due to particle-fluid interaction is simulated using a combination of the unresolved DEM coupled with CFD. The detachment of individual dust particles adhered to a single bulk particle is numerically investigated, and force related detachment functions applicable in the unresolved DEM/CFD are derived based on empirical expressions for the fluid force. The newly derived approach is benchmarked at the bulk level and allows for a more detailed prediction of dust detachment.
Article
Instruments & Instrumentation
Georg Maier, Marcel Reith-Braun, Albert Bauer, Robin Gruna, Florian Pfaff, Harald Kruggel-Emden, Thomas Laengle, Uwe D. Hanebeck, Juergen Beyerer
Summary: Sensor-based sorting provides cutting-edge solutions for separating granular materials. Current line-scanning sensors used in these systems can only produce a single observation of each object without providing data on its movement. Recent studies suggest that using an area-scan camera can reduce characterization and separation error. A predictive tracking approach based on Kalman filters allows for estimating object paths and parameterizing motion models using a multiobject tracking system.
TM-TECHNISCHES MESSEN
(2023)
Article
Engineering, Chemical
Timo Dobler, Simon Buchheiser, Thomas Gaschler, Stefan Platzk, Harald Kruggel-Emden, Hermann Nirschl, Marco Gleiss
Summary: Solar cells, LCDs, and LEDs have become increasingly important, but they rely on rare metals that are only available in limited quantities. Recycling processes, particularly those that enable selective recovery of individual components, are gaining importance to meet rising demand. A possible method is particle-loaded solvent extraction followed by mechanical processing. Through laboratory tests, it was shown that the recovery and purification of rare metals like indium oxide can be achieved, making continuous and selective recovery feasible.
Article
Engineering, Chemical
S. R. Reinecke, S. Blahout, Z. Zhang, T. Rosemann, J. Hussong, H. Kruggel-Emden
Summary: Classical fractionation principles do not work well for microparticles, so specific methods are being developed for fractionating particles in that size range. One such approach is the use of serpentine microchannels, which have been mainly used for size fractionation but also seem to be effective for density fractionation. To optimize the design of these systems for size and density fractionation, detailed information on the combined influence of these factors on equilibrium streaks is needed. Using a coupled DEM-LBM simulation approach, we studied these effects and found that serpentine channels can effectively fractionate particles by density, with the greatest density dependency occurring at higher Reynolds numbers and in channel sections orthogonal to the main channel orientation.
Article
Engineering, Chemical
V. Brandt, J. Grabowski, N. Jurtz, M. Kraume, H. Kruggel-Emden
Summary: DEM-CFD is computationally demanding and limited to lab-scale systems, so coarse-graining approaches are used to summarize particles. This study compares force scaling models in different beds to eliminate influences and identifies optimal scaling rules based on physical parameters. It also analyzes fluidized beds to determine the suitability of scaling models for systems governed by both contact and hydrodynamic forces, providing recommendations for future simulations of industrial-scale particle systems.
Review
Horticulture
Christian Dittrich, Ralf Pecenka, Benjamin Selge, Christian Ammon, Harald Kruggel-Emden
Summary: This study investigates the influence of processing parameters, such as aperture setting, moisture content, and specific energy demand, during twin-screw extrusion on the fiber properties of poplar wood chips. The results show that the processed wood chip fibers have acceptable water-holding capacity when the appropriate aperture setting and specific energy demand are used.
