Article
Engineering, Chemical
Chengxiang Li, Yizhou Cui, Xiaogang Shi, Jinsen Gao, Xingying Lan
Summary: This study evaluates the applicability and accuracy of three widely-used mass transfer models in the simulations of mass transfer in bubble columns. By comparing simulation results with experimental data, suggestions on choosing a proper mass transfer model are provided. The influence of bubble-induced turbulence and its different modeling approaches on different mass transfer models are also investigated.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Y. Jin, R. F. Cavero, C. Weiland, M. Hoffmann, M. Schlueter
Summary: This study investigates the effects of bubble-induced turbulence on the interfacial species transport through direct numerical simulation (DNS). A volume-of-fluid (VOF) method is used to simulate the multiphase flow with one or two deformable bubbles in a box. The results show that bubble-induced turbulence enhances the oscillation of the transient Sherwood number, but has marginal effects on the time-averaged value. On the other hand, the time-averaged Sherwood number increases with an increase in gas volume fraction, indicating that convection plays a more important role in species transport when the bubbles are more densely populated.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Computer Science, Interdisciplinary Applications
Chao Yan, James G. McDonald
Summary: The ten-moment equations are a first-order alternative to the Navier-Stokes equations in the absence of heat transfer. They are advantageous due to their first-order hyperbolic conservation laws. However, the lack of suitable turbulence models limits their applicability.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Engineering, Chemical
Sercan Erdogan, Thomas Schulenberg, Olaf Deutschmann, Martin Woerner
Summary: This study conducted numerical simulations to model bubble induced turbulence at different scales, identifying suitable closure relations for the liquid phase turbulence kinetic energy equation. Simulations of an industrial bubble column considered liquid phases, gas phases, and turbulence, with results showing reasonable agreement with experimental measurements.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Engineering, Chemical
Francesco Maniscalco, Antonio Buffo, Daniele Marchisio, Marco Vanni
Summary: The study utilized large eddy simulation (LES) turbulence approach to simulate bubble columns under various gas velocities and operating conditions, aiming to develop a general model for industrial cases with satisfactory accuracy and moderate computational resources. The study found that the LES methods, particularly the Smagorinsky model, produced more accurate results compared to the standard k-epsilon RANS model, especially for systems with non symmetrical gas feed, despite slightly higher computational time.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Engineering, Chemical
Shuli Shu, Ning Yang, Francois Bertrand, Jamal Chaouki
Summary: This study uses GPU-accelerated fine-grid simulation with an unsteady k-epsilon model to predict bubble plumes in 3D bubble column reactors without considering the influence of lift force. The research highlights the effectiveness of this approach in capturing the bubble plumes in 3D systems.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Mechanics
Bernardo P. Brener, Matheus A. Cruz, Roney L. Thompson, Rodrigo P. Anjos
Summary: This study explores the ill conditioning of the Reynolds average Navier-Stokes (RANS) equations when employing an explicit data-driven Reynolds stress tensor closure, showing that ill conditioning occurs across various cases even when the linear term of the Reynolds stress tensor is treated implicitly. The study proposes a new strategy for solving the RANS equations that outperforms previous procedures in mitigating error propagation to the mean velocity field, emphasizing the importance of incorporating information from the DNS mean velocity field.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Chemical
Ai Wang, Geoffrey Evans, Subhasish Mitra
Summary: In mineral flotation, understanding the dynamics of bubble surface loading (BSL) due to particle attachment and detachment is crucial for the separation kinetics of valuable minerals. This review provides an overview of current techniques for measuring BSL in both quiescent liquid and typical flotation environments. The acoustic emission method shows promise for online measurement in industrial systems, although its implementation has not been satisfactory yet. Challenges remain in estimating the BSL parameter and understanding its impact on the flow field around particle-laden bubbles and the drag coefficient. Coalescence behavior is delayed in the presence of surface loading, leading to the loss of surface energy. Future research should focus on addressing these challenges and finding solutions.
MINERALS ENGINEERING
(2023)
Article
Engineering, Chemical
Y. Mezui, A. Cartellier, M. Obligado
Summary: This study investigates the liquid phase properties in a bubble column through experimental methods. The reactor, with a diameter of 40 cm, can operate in both homogeneous and heterogeneous regimes, with maximum superficial gas velocities and void fractions of 23.2 cm/s and 30%, respectively. Measurements were taken using a Pavlov tube with a temporal resolution of 20 Hz, covering various superficial gas velocities and axial and radial positions. The findings suggest that bubble-induced turbulence models developed for the homogeneous regime can be applied, to some extent, in the heterogeneous regime, with a-3 power law observed in the liquid velocity spectra and integral scales related to the column's diameter. (c) 2022 Elsevier Ltd. All rights reserved.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Xin Tang, Songlin Xu
Summary: Computational fluid dynamic simulations of bubble column flows were conducted using the software Fluent, with a focus on two-phase turbulent modalities. The study investigated six different TPTMs, concluding that the single-phase-and-BIT modality is suitable for simulating bubble column flows, while the single-phase and per-phase modalities are also recommended with BIT modification. Additionally, the mixture modality was found to be unique and can be used as a simplified approach.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Engineering, Chemical
Maathangi Ganesh, Sadegh Dabiri
Summary: Direct numerical simulations were conducted to analyze the dynamics and destratification effects of a large number of bubbles rising in unbounded stratified fluids. The influence of bubble deformability and Reynolds numbers on background mixing was investigated, revealing that highly deformable, high Reynolds number bubbles enhance mixing. The study also examined the influence of bubble motion on liquid and bubble velocity fluctuations, as well as turbulent kinetic energy levels. The results demonstrated an increase in buoyancy flux and vertical mass flux as void fraction and stratification strength varied.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Multidisciplinary Sciences
Rachel L. Bauer, Cody J. Thomas, Everett V. P. Baker, Emily M. Johnson, Kelly R. Williams, Martin J. Langenderfer, Catherine E. Johnson
Summary: Vortex ring collisions have attracted significant interest, and this study presents the formation of a shock wave resulting from the collision of explosively formed subsonic vortex rings, indicating the potential for further research in this area.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Chemical
Jiachen Liu, Xiaoping Guan, Ning Yang
Summary: One of the challenges in CFD simulation of gas-liquid flow is the modeling of shear-induced turbulence (SIT) and bubble-induced turbulence (BIT). This paper aims to investigate this issue and the coupling mechanisms of SIT and BIT. The results show that the effect of BIT models varies, with the Sato or TH model having a significant effect and the Simonin model having a marginal effect. The coupling mechanisms of BIT and SIT also differ depending on the SIT models used.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Tian Ma, Yixiang Liao, Hendrik Hessenkemper, Dirk Lucas, Andrew D. Bragg
Summary: Recent experiments have shown that increasing the concentration of surfactants leads to an increase in bubble-induced turbulence (BIT), despite the slower rise of the bubbles. This phenomenon has not been considered in the standard Reynolds-averaged Navier-Stokes (RANS) modeling for BIT, which uses the Ansatz with source terms added to the transport equation for turbulent kinetic energy and dissipation. The problematic issues related to the closure of the liquid-phase turbulence kinetic energy equation are also discussed. Furthermore, this issue is demonstrated through simulations using a two-fluid approach.
CHEMICAL ENGINEERING & TECHNOLOGY
(2023)
Article
Mechanics
Jianghui Zhu, Guohong Wu, Xiangyu Duan, Xiaoqin Li, Xuelin Tang
Summary: This study numerically investigates hydraulic transients caused by a fast-closing needle valve and water hammer-induced cavitation-vortex flow. The predicted pressure evolutions show reasonable agreement with experimental data. The interfacial surface tension-based model is found to be the most accurate in predicting transient pressure evolutions, followed by the kinematic viscosity-based model and the Singhal cavitation model.
Article
Agronomy
Namrata Pathak, Oluwafemi J. Caleb, Cornelia Rauh, Pramod V. Mahajan
POSTHARVEST BIOLOGY AND TECHNOLOGY
(2019)
Article
Biotechnology & Applied Microbiology
Giovanni Luz, Christopher McHardy, Christoph Lindenberger, Cornelia Rauh, Antonio Delgado
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2019)
Article
Engineering, Manufacturing
Graziele G. Bovi, Oluwafemi J. Caleb, Cornelia Rauh, Pramod V. Mahajan
PACKAGING TECHNOLOGY AND SCIENCE
(2019)
Article
Food Science & Technology
Anna-Sophie Stuebler, Uri Lesmes, Volker Heinz, Cornelia Rauh, Avi Shpigelman, Kemal Aganovic
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
(2019)
Review
Food Science & Technology
Timo Classen, Pia Seidl, Soebiakto Loekman, Bernhard Gatternig, Cornelia Rauh, Antonio Delgado
CURRENT OPINION IN FOOD SCIENCE
(2019)
Article
Optics
Albert Mink, Christopher McHardy, Lena Bressel, Cornelia Rauh, Mathias J. Krause
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2020)
Article
Biotechnology & Applied Microbiology
Sun-Hwa Jung, Christopher McHardy, Cornelia Rauh, Alexander Jahn, Giovanni Luzi, Antonio Delgado, Rainer Buchholz, Christoph Lindenberger
Summary: This paper presents a new approach to predict the growth of algae inside photobioreactors using a simple enzymatic kinetics model to describe the interaction between photons and the photosynthetic unit. The proposed model results in a mixed-inhibition scheme with multiple inhibition sites.
BIOPROCESS AND BIOSYSTEMS ENGINEERING
(2021)
Article
Food Science & Technology
Alexander Rudolph, Amna El-Mohamad, Christopher McHardy, Cornelia Rauh
Summary: This study investigated the concentration of fruit juices and model solutions using CO2 hydrate technology, finding that the bubble column reactor operates best at 37.5 bar and 3 degrees C. Analysis via HPLC and UV/VIS spectrophotometry showed that the hydrate technology separates substances gently during the concentration process.
Correction
Biotechnology & Applied Microbiology
Sun-Hwa Jung, Christopher McHardy, Cornelia Rauh, Alexander Jahn, Giovanni Luzi, Antonio Delgado, Rainer Buchholz, Christoph Lindenberger
BIOPROCESS AND BIOSYSTEMS ENGINEERING
(2021)
Article
Biotechnology & Applied Microbiology
Eric Morelle, Alexander Rudolph, Christopher McHardy, Cornelia Rauh
Summary: Foams play a significant role in food production, especially during beverage bottling. Through experiments and neural network technology, researchers have improved understanding of the influence of flow and material properties on foam behavior. This can help enhance efficiency in the bottling process and reduce issues caused by foam.
FOOD AND BIOPRODUCTS PROCESSING
(2021)
Article
Food Science & Technology
Elisabeth Hoegg, Cornelia Rauh
Summary: This study aimed to predict the high-moisture texturization of plant-based proteins at different water contents for the production of high-moisture meat analogs. High-moisture extrusion experiments were conducted and the sensory evaluation of the obtained samples led to the development of a texturization indicator. The use of this indicator could help minimize the resources required for expensive extrusion trials in the industry.
Article
Food Science & Technology
Elisabeth Hoegg, Cornelia Rauh
Summary: It is important to determine the thermophysical properties of high-moisture extruded samples (HMESs) in order to understand the texturization process of high-moisture extrusion (HME) for the production of high-moisture meat analogues (HMMAs). The specific heat capacity and apparent density of high-moisture extruded samples made from soy protein concentrate (SPC ALPHA(& REG;) 8 IP) were experimentally determined and simple prediction models were developed. The thermal conductivity and thermal diffusivity were calculated based on generic equations and literature models, showing a significant mutual influence. The combination of experimental data and prediction models provided a mathematical description of the thermophysical properties of the HME samples.
Article
Food Science & Technology
Ann-Marie Kalla-Bertholdt, Anne Kathrin Baier, Cornelia Rauh
Summary: Pea protein is highly valued in the food industry due to its low allergenicity and high nutritional value. However, it often lacks functionality, such as solubility. This study investigated the effects of high-intensity ultrasound on protein-fiber suspensions and found that ultrasound can improve protein dispersibility and increase the viscosity of fiber solutions. Meanwhile, it does not affect protein digestion and absorption.
Article
Food Science & Technology
Ann-Marie Kalla-Bertholdt, Anne Kathrin Baier, Cornelia Rauh
Summary: Ultrasonication has been found to affect the particle size, solubility, viscosity, and water binding capacity of plant fibers such as citrus, apple, oat, and pea fibers.
Article
Engineering, Chemical
Hannes Leuner, Christoph Gerstenberg, Kai Lechner, Christopher McHardy, Cornelia Rauh, Jens-Uwe Repke
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2020)
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)