Article
Engineering, Chemical
Gongpeng Wu, Mingjian Zhang, Yan He
Summary: Research on solid mixing in multistage circulating fluidized beds reveals characteristics such as increased solid mean residence time and dispersion with higher solid flux. Diffusion coefficient in enlarged sections decreases with height, contrary to traditional risers. These findings indicate enhanced overall solid mixing in the multistage riser compared to traditional systems.
Article
Thermodynamics
Sirui Tong, Bin Miao, Weike Zhang, Lan Zhang, Siew Hwa Chan
Summary: This study presents a computational fluid dynamics model for simulating the catalytic decomposition of methane in a fluidized bed reactor. The model takes into account catalyst deactivation behavior and investigates the effect of gas flow rate. The simulation results show that reducing flow rates can improve reaction conversion rate and catalyst lifespan.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Guillermo Martinez Castilla, Ruben M. Montanes, David Pallares, Filip Johnsson
Summary: As the share of variable renewable electricity increases, thermal power plants need to adapt their operational protocols for grid-balancing services while remaining economically competitive. This work presents a dynamic model of fluidized bed combustion plants for combined heat and power production, including both gas and water-steam sides. The validated model is used to analyze the plant dynamics and evaluate different control strategies, revealing the importance of modeling both sides and the trade-offs between load changes, operational issues, and thermodynamic losses.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Chemical
Xuelian Xing, Chao Zhang, Bin Jiang, Yongli Sun, Luhong Zhang, Cedric Briens
Summary: In this study, the multi-phase Eulerian-Eulerian two-fluid method coupled with the kinetic theory of granular flow was used to investigate the hydrodynamics of particle flows in a lab-scale bubbling fluidized bed. The study aimed to improve the distribution of an injected liquid by enhancing the flow of bubbles entering the spray jet cavity. Results showed that adding a fluxtube to a baffle can enhance bubble flows, while baffles help smooth out variations in gas distribution.
Article
Mechanics
Ming-zhe Zhou, Zi-yang Wang, Xiao-rui Bai, Huai-yu Cheng, Bin Ji
Summary: A multi-scale Euler-Lagrange method is used to study turbulent cloud cavitating flow around a Clark-Y hydrofoil. Macroscopic cavitating structures are simulated using the volume of fluid (VOF) approach, while micro-scale bubbles are modeled using the Rayleigh-Plesset equation and bubble motion equation. The numerical results agree well with experimental data and show clear transitions between different scales of structures. The statistical analysis investigates the evolution of microscopic bubble behaviors.
JOURNAL OF HYDRODYNAMICS
(2023)
Article
Engineering, Chemical
Jaroslaw Grochowalski, Agata Widuch, Slawomir Sladek, Bartlomiej Melka, Marcin Nowak, Adam Klimanek, Marek Andrzejczyk, Marcin Klajny, Lucyna Czarnowska, Bartlomiej Hernik, Minmin Zhou, Sebastian Pawlak, Wojciech Adamczyk
Summary: This paper presents a methodology to mitigate the risk of heating surfaces exposed to particle erosion in a circulating fluidized bed boiler. A machine learning algorithm is developed to support boiler reliability management. The virtual procedure using digital models provides answers for scenarios that cannot be studied during boiler operation. The predictive model developed in this work provides feedback to the control systems regarding changes in operating conditions and reduces erosion effect.
Article
Engineering, Chemical
Suyang Pan, Jiliang Ma, Daoyin Liu, Xiaoping Chen, Cai Liang
Summary: This paper studies the liquid transport behaviors in a top-sprayed fluidized bed using bed conductance analysis, pressure fluctuation analysis, and bubble image processing. The results show that liquid initially gets trapped in agglomerates before converting to free liquid and spreading from the upper-middle bed to the bottom bed. The disintegrating pattern of agglomerates affects the increase and saturation of free liquid in the bed. The liquid transport process is accelerated by increasing superficial air velocity and particle diameter, while it slows down with increased liquid viscosity and surface tension.
Article
Mechanics
Xiaosong Zhang, Jianhua Wang, Decheng Wan
Summary: The study focused on the effect of nonuniform bubble size distribution on bubble drag reduction (BDR) in experimental processes. A numerical method capable of simulating bubble breakup and coalescence was developed to investigate this phenomenon, demonstrating its advantages through simulating the evolution of bubble diameters.
Article
Engineering, Chemical
Dongfang Li, Runxia Cai, Seokgi Ahn, Xiaofeng Lu, Sungmook Jung, Chung-Hwan Jeon, Xing Zhu
Summary: Five field tests were conducted to measure the pressure drops in the transport zone of a 550-MWe CFB boiler in order to investigate its hydrodynamics. The calculated circulating rates Gs were compared with estimations based on elutriation constant and saturation-carrying capacity theories, showing good agreement for the elutriation constant but discrepancies for the saturation-carrying capacity. The effect of riser diameter on Gs was discussed, indicating an independence of the circulating rate beyond a certain dimension.
Article
Thermodynamics
Zihong Xia, Shuai Yan, Caixia Chen, Xuan Qu, Jicheng Bi
Summary: The study conducted numerical modeling of CCHG in a pressurized bubbling fluidized bed using the MP-PIC algorithm, validating gas-solid flow dynamic properties and CH4 formation behavior. It comprehensively explored the trajectory and physiochemical properties of char particles during the whole residence time.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Energy & Fuels
Dali Kong, Shuai Wang, Kun Luo, Jiahui Yu, Jianren Fan
Summary: The methanation process in a bubbling fluidized bed (BFB) reactor is studied using computational fluid dynamics-discrete element method (CFD-DEM) with thermochemical sub-models. A novel algorithm is developed for bubble identification and statistics. The effects of key operating parameters on bubble behaviors are quantified and the underlying mechanism of mesoscale bubble behaviors is elucidated. The results show that the bubble dynamics can be well captured by the algorithm and the interphase heat and mass transfer can be enhanced by adjusting the operating parameters.
Article
Engineering, Chemical
Keying Ma, Zeneng Sun, Yuanyuan Shao, Jesse Zhu
Summary: The bubble size and rise velocity were investigated in a pilot-scale bubble-induced three-phase inverse fluidized bed. The study found that the bubble size distribution is affected by bubble coalescence and breakup, and proposed a parameter to describe the distribution width. The average bubble size increases with the axial distance and gas velocity until reaching a relatively stable size. The radial distributions of the average bubble size are almost uniform but experience a decreasing trend near the column wall. The bubble rise velocity increases with the bubble size and gas velocity.
Article
Energy & Fuels
Guillermo Martinez Castilla, Ruben M. Montanes, David Pallares, Filip Johnsson
Summary: The aim of this study is to investigate the dynamic performance of large-scale BFBC plants when accounting for both the gas and water-steam sides. A dynamic model of BFB-CHP plants is presented by connecting a model of the gas side to a process model of the water-steam side. The validation shows that the model can satisfactorily describe both multi-load steady-state operation and load transients. The simulation results highlight the fact that the water-steam side achieves stabilization more rapidly after changes in the DH line and steam delivered to customers, as compared to changes in the combustor load.
Article
Engineering, Chemical
Guillermo Martinez Castilla, Ruben M. Montanes, David Pallares, Filip Johnsson
Summary: This study presents a dynamic model of the reactive side of large-scale fluidized bed boilers, validated against operational data from industrial units, and analyzes the performance of the boilers under transient conditions. The results highlight the key role of heat capacity in stabilization time, and show that gas velocity and load condition also affect the stability of the boilers.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Green & Sustainable Science & Technology
Witold Zukowski, Przemyslaw Migas, Marta Zurek, Jan Wrona
Summary: The results of the n-hexane oxidation process in a fluidized bed reactor with a catalytic bed are presented. Baffles were used to modify the flow in the reactor and improve the process efficiency. The best results were achieved with the use of horizontal elements in the form of grids, which significantly improved the conversion of n-hexane to carbon dioxide.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Chemical
Sheng Wang, Olivier Desjardins
CHEMICAL ENGINEERING SCIENCE
(2018)
Article
Mechanics
M. Houssem Kasbaoui, Donald L. Koch, Olivier Desjardins
JOURNAL OF FLUID MECHANICS
(2019)
Article
Mechanics
M. Houssem Kasbaoui, Donald L. Koch, Olivier Desjardins
JOURNAL OF FLUID MECHANICS
(2019)
Article
Computer Science, Interdisciplinary Applications
John Palmore, Olivier Desjardins
JOURNAL OF COMPUTATIONAL PHYSICS
(2019)
Article
Engineering, Chemical
Michael C. Baker, Bo Kong, Jesse Capecelatro, Olivier Desjardins, Rodney O. Fox
Article
Physics, Fluids & Plasmas
M. C. Baker, R. O. Fox, B. Kong, J. Capecelatro, O. Desjardins
PHYSICAL REVIEW FLUIDS
(2020)
Article
Physics, Fluids & Plasmas
Karl Cardin, Sheng Wang, Olivier Desjardins, Mark Weislogel
Summary: The experimental investigation on large liquid jet rebound following oblique jet impacts on superhydrophobic substrates shows the dependence of flow structure on dimensionless groups such as Reynolds number and Weber number. Simple models are developed to predict landing geometry and instability onset, which yield good agreement with experiments and simulations, indicating new transport capabilities.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Computer Science, Interdisciplinary Applications
Michael B. Kuhn, Olivier Desjardins
Summary: High-fidelity simulations of liquid-gas flows with compressibility effects are essential for unlocking insights and developments in engineering contexts. This work introduces a robust and conservative flow solver that can simulate shocks, liquid-gas interfaces, and turbulence, using numerical innovations such as a hybrid advection scheme, unsplit semi-Lagrangian method, and pressure projection scheme. The algorithm is validated through benchmark tests, demonstrating its accuracy and stability in predicting compressible effects, turbulent dissipation, and interface dynamics.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Cyril Bozonnet, Olivier Desjardins, Guillaume Balarac
Summary: This paper presents a novel traction open boundary condition to address issues encountered in simulations, demonstrating its accuracy and stability in various flow scenarios.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Robert Chiodi, Olivier Desjardins
Summary: This study introduces a general, geometrically robust, and efficient polyhedron intersection algorithm based on the half-edge data structure, as well as a novel method for distributing polyhedron volume over a computational mesh. Both methods demonstrate superior performance, with the polyhedron intersection algorithm showing faster speed and the volume distribution method proving to be discretely conservative.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mechanics
Cyril Bozonnet, Jean-Philippe Matas, Guillaume Balarac, Olivier Desjardins
Summary: This study fills the gap in simulating shear instability under experimental conditions and achieves consistent results through convergence research using multiple methods. Additionally, the study explores the effects of confinement on flow stability and instability transition.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Palash Sashittal, Robert Chiodi, Timothy B. Morgan, Olivier Desjardins, Theodore J. Heindel, Daniel J. Bodony
Summary: Non-invasive visualization techniques are essential for understanding primary atomization and sprays in multiphase flows. The researchers in this study used back-lit imaging and Dynamic Mode Decomposition (DMD) to identify the liquid-gas interface and analyze the instabilities of a liquid jet surrounded by an airblast atomizer. However, DMD was not suitable for interface tracking, so they proposed a data-driven two-step approach using optical sensor data. The method successfully reconstructed and predicted the flow while maintaining the sharpness of the fluid interface.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Mechanics
Michael B. Kuhn, Olivier Desjardins
Summary: This study investigates a parametric study of a pure liquid jet in supersonic crossflow using computational schemes. The simulations are validated against experimental results and the effect of numerical resolution on flow behavior is analyzed. The study reveals that increasing the flowrate leads to a further penetration and dispersion of the spray, but has little effect on the droplet size distribution.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Mechanics
Dan Hagan, Meagan Wengrove, Yves Dubief, Olivier Desjardins, Donya Frank-Gilchrist, Joseph Calantoni
Summary: A volume-filtered large eddy simulation (LES) is conducted to investigate the effect of oscillatory flow on a mobile rippled bed. The simulation results show good agreement with experimental data and provide insights into the flow structures and particle transport in the system. This study is important for understanding the dynamic behavior and sediment transport in granular beds.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2023)
Article
Engineering, Multidisciplinary
J. Carmona, N. Odier, O. Desjardins, B. Cuenot, A. Misdariis, A. Cayre
Summary: This research presents a computational study on liquid injection systems to reproduce realistic conditions and validate the proposed methodology for reducing computational costs.
ATOMIZATION AND SPRAYS
(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.