Article
Mechanics
Sibel Tas-Koehler, Martin Neumann-Kipping, Yixiang Liao, Eckhard Krepper, Uwe Hampel
Summary: In this study, the capabilities of Eulerian-Eulerian CFD two-phase flow simulation with the homogeneous Multiple Size Group Model (MUSIG) were assessed under three-dimensional flow conditions. The simulation results generally agreed well upstream of the obstacle, but had deviations downstream, especially in the region of strong vortex in the shadow of the obstacle. Further model improvement is needed to balance the gas fraction in this area.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Engineering, Chemical
Ryo Kurimoto, Shin Takaya, Kosuke Hayashi, Akio Tomiyama
Summary: This study investigates the relationship between bubbly flow characteristics and fouling control through experiments. The results show that the presence of membranes and bubble coalescence enhance the rate of large bubbles in XG-W liquid phase. The gas holdup is found to be a potential indicator for estimating fouling probability.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Mechanics
Majid Rodgar, Helene Scolan, Jean-Louis Marie, Delphine Doppler, Jean-Philippe Matas
Summary: The study experimentally examined the behavior of a bubble injected into a horizontal liquid solid-body rotating flow, showing how factors such as bubble size, rotation speed, and buoyancy impact the bubble's aspect ratio and movement. The study also found that at certain extreme conditions, such as when the Reynolds number exceeds 3000, the bubble can experience abrupt transitions and potentially break up due to resonance between the periodic forcing of the rotating cell and the eigenmodes of the stretched bubble.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Declan B. Gaylo, Kelli Hendrickson, Dick K. P. Yue
Summary: This study focuses on the evolution of the bulk bubble-size distribution under the influence of turbulence-induced fragmentation and free-surface entrainment, finding two regimes based on the entrainment distribution dependence. The weak injection regime is independent of the entrainment distribution, while the strong injection regime's power-law slope is determined by gamma.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
C. M. P. Rosero, G. E. O. Celis, J. B. R. Loureiro, A. P. Silva Freire
Summary: The study discusses the phenomenology of bubble breakup and coalescence in a vertical pipe with an expansion and contraction, using optical techniques to characterize the interactions and processes. It is found that breakup events are largely determined by dynamic pressure forces of turbulent motion, but shear induced breakup is also observed. The formation of gas pockets in the contraction is identified as a significant promoter of bubble breakup.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Mechanics
G. E. O. Celis, C. M. P. Rosero, J. B. R. Loureiro, A. P. Silva Freire
Summary: This study investigates the dynamics of large and small bubbles in sudden expansions and contractions in vertical pipes, using particle image velocimetry and the shadow sizer technique to obtain data on bubble size and velocity distributions. The results show that bubble breakup and coalescence are primarily governed by dynamic pressure forces, while shear-induced breakup is also observed. The formation of a gas pocket in the contraction is identified as an important factor in bubble breakup.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Thermodynamics
Guang Hu, Yue Ma, Huang Zhang, Qianfeng Liu
Summary: This paper provides a comprehensive evaluation of sub-models for solving the population balance model (PBM) under subcooled boiling conditions in a vertical gas-liquid flow. The detailed analysis of bubble mechanisms and various sub-models including bubble nucleation, condensation, coalescence, and breakup in high temperature and pressure applications is crucial for practical engineering. The results suggest that evaluating PBMs and selecting appropriate models is essential for successful application in engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Ashik Ullah Mohammad Masuk, Ashwanth K. R. Salibindla, Rui Ni
Summary: The experimental study focuses on investigating the breakup mechanisms and probability of Hinze-scale bubbles in turbulence. By tracking both bubbles and surrounding tracer particles, the researchers quantified the breakup probability of bubbles close to the Hinze scale and analyzed different breakup mechanisms. The study also provides models linking turbulence characteristics, bubble deformation, and Weber numbers, ultimately offering a unique way to extract the breakup probability of bubbles near the critical Hinze scale.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Yanju Wei, Zhiqiang Mu, Yajie Zhang, Yajing Yang, Shenghua Liu, Chung K. Law, Abhishek Saha
Summary: This study reports the dynamics and morphology of a droplet passing through a soap film, providing experimental observation and theoretical explanation. The study identifies four sequential responses of the film during the process, and develops physical models and analytical expressions to reveal the underlying physics.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Daniel B. Shaw, Luc Deike
Summary: An experimental study was conducted on bubble coalescence at an air-water interface, examining the evolution of underwater neck and surface bridge. The research explored a wide range of Bond numbers to compare gravity and capillary forces, finding different behaviors for nearly spherical bubbles with Bo << 1 and non-spherical bubbles with Bo > 1. By observing inertial-capillary growth and using a simple oscillatory model, the study characterized the dynamics of both the bubble neck and upper surface in various Bond number scenarios.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Ocean
Arman Ghanavati, Sajad Khodadadi, Mohammad Hassan Taleghani, Mofid Gorji-Bandpy, Davood Domiri Ganji
Summary: In this study, the motion and interaction of a bubble pair rising in a stationary liquid were simulated using the volume of fluid method (VOF). Results showed that four different types of interactions, including coalescence, bouncing, zigzagging, and breakup, can occur between the bubble pair based on the Bond (Bo) and Morton (Mo) numbers. The velocity and drag force of the trailing bubble were found to depend on the separation distance between the bubbles and the wake effect of the leading bubble. A general criterion based on dimensionless numbers was proposed to determine the type of interaction between the bubble pair.
APPLIED OCEAN RESEARCH
(2023)
Article
Chemistry, Analytical
Xiaopeng Shang, Xiaoyang Huang
Summary: This work presents experimental and numerical studies on the dynamics of cavitation bubbles in a nozzle-shaped microfluidic channel with PZT actuations. It is found that a cloud of bubbles can be generated near the center of the microfluidic channel when the actuation voltage is larger than a threshold at 1 kHz. The bubbles oscillate radially with expansion and compression, and translate upstream towards the opening of the nozzle. The bubbles undergo frequent coalescence and breakup, leading to vigorous churning of surrounding liquids. Numerical simulation shows a low-pressure zone inside the microfluidic channel within each cycle of the actuation period, which is responsible for bubble generation observed in the experiments. The method of bubble generation in this study is novel and can be applied for the enhancement of heat and mass transfer in microfluidic operations.
Article
Mechanics
J. Ruiz-Rus, P. Ern, V Roig, C. Martinez-Bazan
Summary: This study experimentally investigates the coalescence cascade process of a swarm of deformable bubbles. The stages of the coalescence cascade are characterized by the diameter of the largest bubbles. The collision frequency and coalescence efficiency of different sized bubbles are obtained from the experiments. Models describing the collision frequency for different coalescence regimes are provided.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Chemical
Yingdong Wu, Zhongqiu Liu, Baokuan Li, Yong Gan
Summary: A population balance model based on the multiple-size-group (MUSIG) approach was developed for investigating multi-size bubbly flow in a slab continuous casting mold. The study found that both water and gas flow rates have significant impacts on bubble size distribution, gas volume fraction, and turbulence intensity in the liquid phase.
Review
Engineering, Chemical
Sheng-lin Yan, Xu-qing Wang, Li-tao Zhu, Xi-bao Zhang, Zheng-hong Luo
Summary: This review comprehensively analyzes the kinetics of bubble behaviors and the mechanisms of gas-liquid mass transfer. It discusses the correlations between bubble behavior and mass transfer, as well as modeling approaches. The impact of global and local turbulence on bubble behavior and mass transfer is also discussed.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Ronald Lehnigk, William Bainbridge, Yixiang Liao, Dirk Lucas, Timo Niemi, Juho Peltola, Fabian Schlegel
Summary: Polydispersity is a challenging feature in many industrial and environmental multiphase flows, affecting all related transfer and transport processes. Using a population balance model based on the method of classes allows tracking the evolution of particles with different secondary properties, improving the prediction of size distribution.
Article
Mechanics
Tian Ma, Hendrik Hessenkemper, Dirk Lucas, Andrew D. Bragg
Summary: This study experimentally investigates the properties of bubble-laden turbulent flows at different scales, with a focus on flow kinetic energy, energy transfer, and extreme events. The results show that the flow exhibits anisotropy and the degree of anisotropy increases with the order of the structure functions. The energy transfer associated with the horizontal velocity component is downscaled, while the energy transfer associated with the vertical component is upscaled. The probability density functions of velocity increments indicate that extreme values become more likely with decreasing Reynolds number, contrary to single-phase turbulence. Visualization of extreme events reveals intense small-scale velocity increments near the turbulent/non-turbulent interface at the boundary of the bubble wake.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Hamed Setoodeh, Amirhosein Moonesi Shabestary, Wei Ding, Dirk Lucas, Uwe Hampel
Summary: In this study, the GENTOP concept and a mechanistic bubble dynamics model were implemented to simulate the upward subcooled flow boiling inside a vertical heating pipe, and the wall heat transfer was investigated.
APPLIED THERMAL ENGINEERING
(2022)
Article
Nuclear Science & Technology
Yixiang Liao, Jiadong Li, Dirk Lucas
Summary: This study reveals the influence of gas jet structure on aerosol particle removal mechanisms, including the significance of droplet breakup in the injection zone, the promotion effect of bubble size and velocity on particle deposition, and the impact of gas flow rate on the coalescence probability of rising bubbles.
NUCLEAR ENGINEERING AND DESIGN
(2022)
Article
Mechanics
Junlian Yin, Tingting Zhang, Benjamin Krull, Richard Meller, Fabian Schlegel, Dirk Lucas, Dezhong Wang, Yixiang Liao
Summary: This paper presents the application of a morphology adaptive multifield two-fluid model to predict complex flow in a vane-type gas-liquid separator. The model successfully captures different flow regimes and transitions, and has been validated using OpenFOAM-Hybrid.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Mechanics
Jiadong Li, Yixiang Liao, Igor A. Bolotnov, Ping Zhou, Dirk Lucas, Qing Li, Liang Gong
Summary: This study investigates the heat transfer of a rising vapor bubble in superheated liquid using direct numerical simulation. The vapor-liquid system is described using the one-fluid formulation with the level set method. The effects of bubble deformation and oscillation on interfacial heat transfer are analyzed, showing that the front part of the bubble contributes to the majority of heat transfer.
Article
Nuclear Science & Technology
Ronald Lehnigk, Martin Bruschewski, Tobias Huste, Dirk Lucas, Markus Rehm, Fabian Schlegel
Summary: OpenFOAM_RCS is an information technology environment that assists in the centralized maintenance and upgrade of OpenFOAM. It promotes collaborative development and review processes and upgrades based on snapshots of the latest OpenFOAM development line. It ensures compatibility of downstream code and simulation setups through various checks and establishes a validation database for continuous quality assurance.
Article
Nuclear Science & Technology
Achilleus Hermawan Astyanto, Akhlisa Nadiantya Aji Nugroho, Indarto, I. Gusti Ngurah Bagus Catrawedarma, Dirk Lucas, Deendarlianto
Summary: This study focuses on characterizing the interfacial behaviors in gas/liquid counter-current flow in a large scale of pressurized water reactor's hot leg using time and frequency domain analyses. The visualizations captured by high-speed cameras were processed using a pixel identification algorithm to track the dynamics of liquid holdup fluctuations. Advanced statistical tools including probability density function, power spectral density function, and discrete wavelet transform were applied to analyze the data. The results indicate that flooding starts with the appearance of a wavy interface which later develops into a roll or large wave, blocking the cross-sectional area of the conduit. The pressure of the system affects the frequency occurrence of slugging, while the injected gas flow rate behaves differently. Moreover, the Kolmogorov entropy correlates the stabilizing effect due to fluid resistance with the system pressure or fluid properties. Additionally, there were no significant differences in the flooding mechanisms between air/water and steam/water flows.
NUCLEAR ENGINEERING AND DESIGN
(2023)
Article
Thermodynamics
Jiadong Li, Yixiang Liao, Ping Zhou, Dirk Lucas, Qing Li
Summary: In this study, the two-fluid model (TFM) is combined with the population balance model (PBM) to track the spatial and temporal change of bubble size and interfacial area concentration (IAC) in flashing flows. The model is validated for bubble growing in stagnant superheated liquid and applied to flashing pipe flows, where coalescence, breakup, and interfacial heat transfer coefficient (HTC) play important roles in determining the bubble size distribution and IAC. The neglect of these phenomena and inappropriate choice of HTC closure can lead to significant errors in predicting the bubble size and IAC.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Mechanics
Li-Song Wang, Benjamin Krull, Dirk Lucas, Richard Meller, Fabian Schlegel, Matej Tekavcic, Jing-Yu Xu
Summary: This paper presents a multifield two-fluid model for simulating annular flow and proposes a new droplet entrainment model. Through experimental validation and comparison with literature models, the accuracy of the new model in simulating liquid film and droplet fraction is demonstrated.
Article
Engineering, Chemical
Yixiang Liao, Dirk Lucas
Summary: This study establishes a computational fluid dynamics (CFD) model to analyze the phase change during flashing-induced instability (FII). Experimental data is incorporated to validate the model and investigate the transient flow field and thermodynamic behavior. The results reveal the challenges and limitations of the current model and suggest improvements for future numerical studies.
Article
Engineering, Chemical
Jiadong Li, Yixiang Liao, Ping Zhou, Dirk Lucas, Liang Gong
Summary: In this study, the flashing flow of sub-cooled water in a converging-diverging nozzle was investigated using the two-fluid model. The thermal non-equilibrium effect of phase change was considered with an interfacial heat transfer model, while the pressure jump across the interface was ignored. The results were compared with experimental data, and satisfactory agreement was obtained for the axial pressure distribution and flashing inception. However, some discrepancies were observed in the vapor production and radial gas volume fraction distribution.
Article
Energy & Fuels
Hong-Jie Yan, He-Yang Zhang, Hui-Min Zhang, Yi-Xiang Liao, Liu Liu
Summary: In order to investigate the migration mechanism and wake behavior of a single bubble rising near a vertical wall, three-dimensional direct numerical simulations were conducted using the open-source software Basilisk. Different types of migration paths, including linear, zigzag, and spiral, were examined. The results revealed that the vertical wall hindered the diffusion of the vortex boundary layer on the surface of the bubble moving in a straight line, resulting in a reaction force that pushed the bubbles away from the wall surface. The stability of the bubble's motion depended on the plane in which it moved.
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)
