Article
Thermodynamics
Sanaa Kouzbour, Bouchaib Gourich, Youssef Stiriba, Christophe Vial, Fabrice Gros, Rahmat Sotudeh-Gharebagh
Summary: The study found that different surfactants have varying effects on gas-liquid interfaces, with ester increasing gas hold-up, while amine is similar to tap water unless at a certain gas velocity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Chemical
Jiaqi Chen, Caleb S. Brooks
Summary: Flow visualization, Particle Image Velocimetry (PIV) and dissolved oxygen charging experiments were conducted in a small-scale cylindrical air-water bubble column at different superficial gas velocities. Results included void fraction profile, total gas holdup, liquid phase velocity field, and volumetric mass transfer coefficient. By analyzing experimental results and comparing with simulations, a validated CFD model for multiphase mass transfer was established for future reactor design.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Mechanics
Sanaa Kouzbour, Francesco Maniscalco, Antonio Buffo, Marco Vanni, Francesc Xavier Grau, Bouchaib Gourich, Youssef Stiriba
Summary: This study investigated the effects of sodium dodecyl sulfate (SDS) surfactant on mass transfer coefficients in a square bubble column reactor. Experimental results showed that the presence of SDS increased the overall gas holdup and enhanced the gas-liquid mass transfer. Numerical simulations confirmed the accuracy of the model and agreed well with experimental data.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Engineering, Chemical
Vincent Ngu, David F. Fletcher, John M. Kavanagh, Yan Rafrafi, Claire Dumas, Jerome Morchaina, Arnaud Cockx
Summary: Biological methanation is a promising technology for storing renewable energy, but the scaling-up process faces challenges in H2 gas-liquid mass transfer. This study demonstrates the significant impact of H2 mass transfer on CH4 purity and productivity through analytical, experimental, and numerical approaches. The findings highlight the importance of sparger design in enhancing mass transfer efficiency and improving bioreactor performance.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Yanling Tang, Gang Luo, Zhenmin Cheng
Summary: The study looks at the impact of packing size on fluid dynamics in an external-loop packed bubble column with Raschig rings of different effective diameters. Gas holdup increases with smaller packing size, while liquid circulating velocity decreases. The maximum gas-liquid mass transfer coefficient occurs with a packing diameter of 14.1 mm.
Article
Engineering, Chemical
Sikandar Almani, Walid Blel, Emilie Gadoin, Caroline Gentric
Summary: This study investigates the hydrodynamics and gas-liquid mass transfer characteristics of non-Newtonian fluids in a thin-gap bubble column. The results show that compared to Newtonian fluids, non-Newtonian fluids result in higher gas holdup and mixing times, but a lower gas-liquid mass transfer coefficient. Additionally, smaller bubbles improve mass transfer while larger bubbles improve mixing.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Zhijie Chen, Xinru Zhang, Bosheng Su
Summary: The study examined the impact of arc baffles on gas-liquid mass transfer in a flat-plate bubble column. It was found that increasing the projection length and bottom clearance of the baffles could enhance mass transfer efficiency, while the shape of the baffles had different effects on mass transfer.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Engineering, Chemical
Tingting Dong, Yongli Ma, Mingyan Liu
Summary: This paper investigates the gas-liquid mass transfer characteristics in a gas-liquid-solid mini fluidized bed (GLSMFB). The study finds that the liquid volumetric mass transfer coefficient and gas-liquid interfacial area increase with the increase of the superficial gas velocity within the experimental parameter range. Additionally, the liquid volumetric mass transfer coefficient increases with the increase of the superficial liquid velocity at the same ratio of superficial gas to liquid velocity.
Article
Engineering, Environmental
Aritra Kar, Vaibhav Bahadur
Summary: This study develops a simulation framework based on fundamental principles to analyze the heat transfer, mass transfer, and interfacial phenomena associated with gas hydrate formation. By simulating CO2 hydrate formation and validating against experimental data, several important conclusions regarding hydrate formation are drawn, such as the adverse impact of inadequate heat dissipation, the importance of small bubble size for growth rates, and the enhancement of CO2 separation efficiency by increasing reactor pressure.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Ahmed Khalil, Diego Rosso, Christopher T. DeGroot
Summary: The study used CFD-PBM model to simulate a bubble column reactor and validate the model against experimental data. The sensitivity analysis showed that the coalescence model of Prince and Blanch provided the best results, and the model was shown to be insensitive to the breakup model. The importance of considering bubble size distribution (BSD) for accurately modeling mass transfer was demonstrated.
WATER ENVIRONMENT RESEARCH
(2021)
Article
Thermodynamics
Elias Eder, Sandro Hiller, Dieter Brueggemann, Markus Preissinger
Summary: Bubble columns are widely used for air humidification in water treatment systems and fuel cells due to their excellent heat and mass transfer properties and low technical complexity. Understanding the humidification process and the impact of operating parameters is crucial for designing and operating these devices efficiently. In this study, a refined method is used to determine the volumetric air-liquid heat and mass transfer coefficients and the humidifier efficiency for different parametric settings. The results show that the transfer coefficients increase with air velocity and liquid temperature, and the outlet humidity decreases with increasing salinity. The study also reveals significant changes in humidifier efficiency for liquid heights smaller than 0.1 m. An efficiency chart is presented to help determine optimal operating conditions and provide recommendations for industrial applications.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Chemical
Vincent Ngu, Jerome Morchain, Arnaud Cockx
Summary: Numerical simulation of biological methanation in bubble column reactors is challenging due to the strong coupling between hydrodynamics, mass transfer, and bioreaction. In this study, a comprehensive model is developed to accurately predict the mass transfer coefficient and gas solubility, which are crucial for simulating the biological methanation process.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Vincent Ngu, Jerome Morchain, Arnaud Cockx
Summary: This study investigates reactive bubbly flow using a comprehensive spatio-temporal 1D model. The gas-liquid hydrodynamics and bubble diameter shrinkage are well captured by the model. Sensitivity analyses reveal the impact of parameters such as liquid axial dispersion coefficient, enhancement factor, and mass transfer coefficient on reactive mass transfer.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Physics, Multidisciplinary
Ali F. Abu-Bakr, Ahmed K. Abu-Nab
Summary: In this study, we propose theoretical and mathematical approaches for lipid-coated multi-microbubbles in viscoelastic tissues during the growth process of microscopic bubbles. Our results demonstrate that the appearance of lipid-coated multi-microbubbles can significantly decrease the radii of microbubbles.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Chemistry, Applied
Phillip Roche, Roderick C. Jones, Brian Glennon, Philip Donnellan
Summary: A lab-scale bubble column was studied as an alternative method for low-temperature binary solvent swap, and both theoretical modeling and experimental results confirmed its effectiveness and accuracy in achieving desired evaporation rates and solvent concentration changes.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Mechanics
Roland Rzehak, Manuel Krauss, Peter Kovats, Katharina Zaehringer
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2017)
Article
Engineering, Environmental
Michael Jokiel, Nicolas Maximilian Kaiser, Peter Kovats, Michael Mansour, Katharina Zaehringer, Krishna Deo Prasad Nigam, Kai Sundmacher
CHEMICAL ENGINEERING JOURNAL
(2019)
Article
Thermodynamics
D. Sarker, W. Ding, R. Franz, O. Varlamova, P. Kovats, K. Zaehringer, U. Hampel
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2019)
Article
Engineering, Environmental
Michael Mansour, Prafull Khot, Peter Kovats, Dominique Thevenin, Katharina Zahringer, Gabor Janiga
CHEMICAL ENGINEERING JOURNAL
(2020)
Article
Engineering, Mechanical
Peter Kovats, Fabio J. W. A. Martins, Michael Mansour, Dominique Thevenin, Katharina Zaehringer
EXPERIMENTS IN FLUIDS
(2020)
Article
Engineering, Mechanical
P. Kovats, C. Velten, M. Mansour, D. Thevenin, K. Zaehringer
EXPERIMENTS IN FLUIDS
(2020)
Article
Engineering, Mechanical
Conrad Mueller, Peter Kovats, Katharina Zaehringer
Summary: The study characterized the mixing of two miscible liquids with the addition of air bubbles in a horizontal helically coiled reactor, showing an increase in mixing coefficient caused by the bubbles. Different mixing patterns were observed at different locations inside the liquid plug depending on the flow structure.
EXPERIMENTS IN FLUIDS
(2021)
Article
Engineering, Chemical
Manuel A. Taborda, Peter Kovats, Katharina Zaehringer, Martin Sommerfeld
Summary: Based on experiments and numerical calculations, this study investigated the influence of liquid viscosity on bubble behavior in a bubble column. The results showed that considering bubble dynamics can significantly alter the numerical simulation results and this model can be adapted for different liquid properties. Good agreement between experimental and numerical results was observed for non-reactive and reactive cases.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2022)
Article
Thermodynamics
Mark W. Hlawitschka, P. Kovats, B. Doenmez, K. Zaehringer, H-J Bart
Summary: This study focuses on the numerical and experimental investigation of the influence of viscosity on bubble motion and reaction in reactive bubble columns. A Euler-Lagrange framework is used to improve the simulation of the complex hydrodynamics/reaction interaction. Experimental data in a cylindrical bubble column was obtained to validate the simulations, and it was found that viscosity and surface tension changed due to the presence of glycerol and surfactants.
EXPERIMENTAL AND COMPUTATIONAL MULTIPHASE FLOW
(2022)
Article
Engineering, Chemical
M. W. Hlawitschka, P. Kovats, K. Zaehringer, H. -J. Bart
CHEMICAL ENGINEERING SCIENCE
(2017)
Article
Engineering, Chemical
Peter Kovats, Dominique Thevenin, Katharina Zaehringer
CHEMICAL ENGINEERING & TECHNOLOGY
(2017)
Article
Mechanics
Nicolas Bouvet, Savannah S. Wessies, Eric D. Link, Stephen A. Fink
Summary: This study presents a framework to characterize firebrand flows and compare exposure through the use of a measurement device and data processing methods. The ability to perform exposure comparisons and recognize combustion states is demonstrated.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
P. Botticini, G. Lavalle, D. Picchi, P. Poesio
Summary: This study investigates the gravity-driven liquid layer problem on an inclined plate, taking into account the variable density of the fluid. The study examines the influence of density variation on the formulation of a depth-averaged model and the role of compressibility in long-wave interfacial instability.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Jean-Paul Caltagirone
Summary: This article introduces a method for modeling capillary flows on a surface or at the interface of two fluids. The method involves handling the two components of capillary acceleration using the divergence and curl of surface normal. The proposed formulation is characterized by directional curvature based on dihedral angle, intrinsic anisotropic surface tension per unit mass, and introduction of capillary potential.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Qi-Teng Zheng, Chun-Bai-Xue Yang, Shi-Jin Feng, Yu-Chen Song, Yong Zhao, Yu-Lin Wu
Summary: This paper proposes a new two-phase partitioning boundary model to accurately predict the drying process of a porous medium from saturated to unsaturated conditions. The model is validated through laboratory soil drying tests and the study also investigates the effects of air-water interfacial area and water retention parameters on the drying process.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Alexandra Metallinou Log, Morten Hammer, Svend Tollak Munkejord
Summary: Flashing flow is commonly found in industrial systems and accurate flashing models are essential for the design of safe and efficient CO2 transportation systems. We propose a homogeneous flashing model that takes into account the physical phenomena of phase change. The model is fitted using CO2 pipe depressurization data and we find that the same model parameters can be applied for different cases.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Q. Tan, S. A. Hosseini, A. Seidel-Morgenstern, D. Thevenin, H. Lorenz
Summary: The possible impact of temperature differences during crystal growth is investigated in this study. A numerical model is developed to simulate the crystallization dynamics of (S)-mandelic acid, taking into account temperature effects. The study shows that the heat generation at the crystal interface has only a small effect on the surrounding temperature field.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Hideki Murakawa, Sana Maeda, Sven Eckert
Summary: This study investigates the behavior of bubbles in a liquid metal under the influence of a magnetic field, particularly bubble chains. The results show that increasing the magnetic field strength suppresses the oscillations of the bubbles and concentrates their crossing positions in a specific area. Applying these findings to numerical models can further optimize continuous casting processes.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Johanna Potyka, Kathrin Schulte
Summary: This paper presents an advanced Volume of Fluid (VOF) method for performing three-dimensional Direct Numerical Simulations (DNS) of the interaction of two immiscible fluids in a gaseous environment with large topology changes. The method includes efficient reconstruction of phase boundaries near the triple line using a Piecewise Linear Interface Calculation (PLIC) method and enhanced surface force modeling with the Continuous Surface Stress (CSS) model. Implementation of these methods in the multi-phase flow solver Free Surface 3D (FS3D) yielded successful validation. The simulations provide valuable insights into the collision process and can support future modeling of immiscible liquid interaction.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Martin Rohde, Sebastian Burgmann, Uwe Janoske
Summary: This study investigates the effect of superimposing an incident flow and two-dimensional vibration on the critical air flow velocity required for the detachment of a droplet. The results show that oscillatory excitation at specific frequencies can significantly reduce the critical velocity for droplet detachment.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Tea-Woo Kim, Baehyun Min
Summary: Liquid-gas two-phase slug flow is a complex flow pattern in energy systems, and accurately predicting slug liquid holdup is crucial for system design and operation. Existing HLLS models have limited applicability due to a lack of physical basis. This study proposes a new dimensionless number SP and correlates it with HLLS data, resulting in a unified HLLS correlation that agrees closely with experimental data.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Christian Lieber, Stephan Autenrieth, Kai-Yannic Schoenewolf, Amy Lebanoff, Rainer Koch, Sterling Smith, Paul Schlinger, Hans-Joerg Bauer
Summary: The observation of acoustically levitated droplets offers great potential for studying their evaporation characteristics. The main objective of this study is to present an experimental setup that minimizes the disturbing effects of the levitation technique in order to investigate convective heat and mass transfer during droplet evaporation.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Facundo Cabrera-Booman, Nicolas Plihon, Mickael Bourgoin
Summary: The settling behavior of individual spheres in a quiescent fluid was experimentally studied. The mean trajectory angle with the vertical showed complex behavior as the parameters Gamma and Ga varied. The transition from planar to non-planar trajectories and the emergence of semi-helical trajectories were observed, especially for denser spheres.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Hongbin Wang, Hanwen Luo, Jinbiao Xiong
Summary: This article introduces an iterative screening method for closure models in nucleate boiling flow simulation, and demonstrates its accuracy through experiments.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Alexandra Metallinou Log, Morten Hammer, Han Deng, Anders Austegard, Armin Hafner, Svend Tollak Munkejord
Summary: This study investigates the rapid depressurization of liquid CO2 and compares the predictions of different models. It is found that higher temperatures result in shorter relaxation times.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Rizwan Zahoor, Sasa Bajt, Bozidar Sarler
Summary: This numerical study evaluates the jet characteristics of non-Newtonian power-law fluids in a gas dynamic virtual nozzle. The results show that shear-thinning fluids result in thicker, longer, and slower jets compared to shear-thickening fluids. Additionally, a dripping-jetting phase diagram of the nozzle is obtained by varying the power law index, gas, and liquid flow rates.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)