Article
Thermodynamics
Xiaofei Zhu, Sen Wang, Qihong Feng, Lei Zhang, Li Chen, Wenquan Tao
Summary: This study employed a lattice Boltzmann model to validate the flow of three immiscible fluids in three-dimensional porous media, and analyzed the effects of wettability, viscosity ratio, and capillary number on relative permeability curves in detail.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Jiajia Liu, Chenggong Li, Yunxin Zhang, Mao Ye, Zhongmin Liu
Summary: The study focused on the rotation behavior of elliptical porous particles in fluid flow, finding that confinement ratio affects the rotation period and critical Reynolds number. The transition from rotating to stationary can be explained by the net torque exerted on the particles.
Article
Environmental Sciences
Mingzhi Wang, Yushi Liu, Beimeng Qi, Abir Al-Tabbaa, Wei Wang
Summary: The study compared the performance of cylindrical media and spherical media in heavy metal immobilization, finding that despite having the same surface area and porosity, spherical media still exhibited a higher immobilization rate. Additionally, the floatation arrangement of spherical media resulted in a higher immobilization rate compared to cylindrical media.
Article
Computer Science, Interdisciplinary Applications
Andre F. V. Matias, Rodrigo C. V. Coelho, Jose S. Andrade Jr, Nuno A. M. Araujo
Summary: The flow through a porous medium is significantly affected by boundary conditions, which are often assumed to be static. Changes in the medium due to swelling and erosion have been considered in extending existing lattice-Boltzmann models. The competition between swelling and erosion determines the steady state, with a transition between regimes where either swelling or erosion dominates.
JOURNAL OF COMPUTATIONAL SCIENCE
(2021)
Article
Engineering, Geological
Mohamad Chaaban, Yousef Heider, Bernd Markert
Summary: In this paper, a reliable micro-to-macroscale framework is presented to model multiphase fluid flow through fractured porous media. The lattice Boltzmann method (LBM) is utilized within the phase-field modeling (PFM) of fractures to achieve this. New phase-field-dependent relationships for various parameters are proposed and a multiscale concept for coupling is achieved. Numerical simulations on real microgeometries of fractured porous media validate the reliability of the model.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Thermodynamics
Sheng Chen, Wenhao Li, Hayder Mohammed
Summary: This study investigates the heat transfer characteristics of natural convection of large Prandtl number fluids in porous media using a novel lattice Boltzmann approach. It reveals significant differences between large and small Prandtl number fluids, with the former more easily transitioning from a convection-dominated process to a conduction-dominated one in porous media.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Computer Science, Interdisciplinary Applications
Mohammad Kazemi, Ali Takbiri-Borujeni, Sam Takbiri, Arefeh Kazemi
Summary: A physics-informed machine learning model is developed to replace numerical simulations of porous media. The model accurately predicts flow fields by learning the communications among grid cells. Generalization of permeability with high accuracy is challenging due to the random arrangements of particles, and building a comprehensive database for different grain/pore arrangements is expensive. The developed model uses deep learning to represent porous media and combines neural network architectures to avoid gradient issues, with the continuity and momentum conservation equations embedded in the loss function.
COMPUTERS & FLUIDS
(2023)
Article
Physics, Fluids & Plasmas
Dario Maggiolo, Francesco Picano, Federico Toschi
Summary: Through pore-scale numerical simulations, it has been shown that directional-dependent two-phase flow behavior can be achieved in anisotropic porous media with controlled design. The results demonstrate distinct invasion dynamics based on the direction of fluid injection relative to the medium orientation.
Article
Thermodynamics
Ping Wang, Ganggang Sun, Bo Dong, Lele Chen, Xuan Zhang, Boyuan Gong
Summary: In this study, the phase-change lattice Boltzmann method was used to simulate evaporation on a porous medium surface. A new wetting boundary scheme was proposed to consider surface wettability. The effect of surface wettability on evaporation in the porous medium was investigated, and it was found that reducing the contact angle of the porous media skeleton can increase the surface evaporation rate when the porous medium is hydrophilic. However, the benefit of decreasing the contact angle to improve the evaporation rate decreases as the contact angle of the skeleton decreases.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Physical
Xiongsheng Wang, Cuicui Yin, Juan Wang, Kaihong Zheng, Zhengrong Zhang, Zhuo Tian, Yongnan Xiong
Summary: The influence of wetting gradient on the viscous fingering phenomenon was studied using the lattice Boltzmann method. It was found that the gradual increase in wettability of the porous media improves the flow front stability and can suppress viscous fingering. The wetting gradient has a more significant effect on flow front stability under conditions of high viscosity ratio and large porosity.
Article
Geosciences, Multidisciplinary
Yihuai Zhang, Branko Bijeljic, Ying Gao, Qingyang Lin, Martin J. Blunt
Summary: The study focuses on the pressure difference during two-phase flow across a sandstone sample with varying injection rates and fractional flows of water. It was observed that there is a transition from linear to non-linear flow with the power-law exponent depending on the fractional flow. By using energy balance, the onset of intermittency for a range of fractional flows, fluid viscosities, and rock types was accurately predicted.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Energy & Fuels
Abdulmajeed Almutairi, Faisal Othman, Jiachao Ge, Furqan Le-Hussain
Summary: This work develops a data-driven surrogate model to replace numerical simulations of porous media and accurately predict flow fields for new simulation runs. The surrogate model, developed using deep learning techniques, improves the prediction of permeability for porous media regardless of grain density and shape, with a significant reduction in computational time compared to previous work limited to a unique grain shape/size.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Chemical
T. O. M. Forslund, I. A. S. Larsson, J. G. Hellstrom, T. S. Lundstrom
Summary: The study evaluates the effects of periodicity assumptions on the macroscopic properties of packed porous beds using a cascaded Lattice-Boltzmann method model. It is found that one unit cell is not enough to represent all structures of fluid flow in unsteady flows, impacting the permeability and dispersive properties of the porous bed. However, a single unit cell accurately represents fluid flow across all cases studied in the steady region.
TRANSPORT IN POROUS MEDIA
(2021)
Article
Mathematics, Applied
Yousef Kazemian, Saman Rashidi, Javad Abolfazli Esfahani, Omid Samimi-Abianeh
Summary: The Lattice Boltzmann method was used to simulate propane-air mixture combustion in porous media with different grain shapes. The effects of these shapes on flow fields, temperature fields, and flame characteristics were investigated. It was found that grains with sharp corners in the porous media provided the highest reverse flow, while rectangular and triangular grains provided the highest and least pressure drop, respectively.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Engineering, Geological
Tomohiro Kitao, Yutaka Fukumoto, Kazunori Fujisawa, Arif Jewel, Akira Murakami
Summary: The study investigates the accuracy of pore-scale intergranular flow analysis using the lattice Boltzmann method with the discrete element method, comparing it with experimental results of saturated seepage flows. The results show that the numerical method successfully predicts macroscopic properties obtained in permeability tests, demonstrating the applicability of the LBM-DEM analysis to pore-scale intergranular fluid flows.
Article
Energy & Fuels
Mohamed Mahrous, Enzo Curti, Sergey Churakov, Nikolaos Prasianakis
Summary: This paper aims to obtain the petrophysical parameters of Indiana limestones in order to reduce uncertainties in core-scale reactive transport simulations of carbonate rocks. By combining high resolution tomography with pore scale calculations, the rock minimum representative volume, frequency distributions of petrophysical parameters, relationships between the parameters, and the spatial correlation model and lengths of the rock have been determined.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Electrochemistry
A. Schuller, T. J. Schmidt, J. Eller
Summary: A new non-invasive method based on electrical impedance tomography is proposed to determine the conductivity distribution in-plane of the PEFC membrane. The method shows potential in accurately reconstructing different conductivity profiles with surface current injection and voltage measurement. However, the accuracy of electrode positioning, cell characterization, and measurement system still need to be addressed.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Energy & Fuels
Kevin M. Tenny, Katharine Greco, Maxime van der Heijden, Tommaso Pini, Adrian Mularczyk, Alexandru-Petru Vasile, Jens Eller, Antoni Forner-Cuenca, Yet-Ming Chiang, Fikile R. Brushett
Summary: This study investigates the impact of compression on porous carbon electrodes using microtomographic imaging, load cell testing, and flow cell diagnostics. It is found that different compressions have distinct effects on electrode structures, fluid dynamics, and cell performance for AvCarb 1071 cloth and Freudenberg H23 paper, with each material having its own optimal compression conditions.
Article
Chemistry, Physical
Christoph Csoklich, Mayank Sabharwal, Thomas J. Schmidt, Felix N. Buchi
Summary: The study suggests that thermal conductivity should not be a decisive criterion for improving fuel cell performance at high current densities, but rather the structure of the gas diffusion layer (GDL).
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Yen-Chun Chen, Chrysoula Karageorgiou, Jens Eller, Thomas J. Schmidt, Felix N. Buchi
Summary: This study characterizes the structural parameters of microporous layer (MPL) coatings on gas diffusion layers (GDLs), including porosity and thickness heterogeneity. The results show that MPLs from different manufacturers exhibit different properties. Additionally, many commercial MPLs display a porosity gradient in the thickness direction.
JOURNAL OF POWER SOURCES
(2022)
Article
Electrochemistry
A. Schuller, T. J. Schmidt, J. Eller
Summary: A non-invasive method is proposed to determine the local humidity and resistance distribution in polymer electrolyte fuel cells. The method uses multiple electrodes to inject alternating currents and interprets the results through interpolation, showing good matching and reproducibility.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Jerry P. Owusu, Konstantinos Karalis, Nikolaos I. Prasianakis, Sergey V. Churakov
Summary: In a nuclear waste repository, gases generated from the corrosion of metals and organic degradation should be able to migrate through the multibarrier system to prevent pressure build-up. Diffusion is identified as the key mechanism for gas transport in water-saturated medium, and the diffusion coefficient is influenced by nanopore size and temperature.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Michael Striednig, Thomas J. Schmidt, Felix N. Buchi
Summary: This paper investigates the interactions between the fuel cell stack and the balance of plant in an evaporatively cooled polymer electrolyte fuel cell system (PEFCS). The study shows that evaporative cooling works effectively over a wide range of operating conditions, with the exhaust gas condenser identified as a critical component for efficient operation and closed water loop.
JOURNAL OF POWER SOURCES
(2022)
Article
Electrochemistry
Hong Xu, Minna Buehrer, Federica Marone, Thomas J. Schmidt, Felix N. Buechi, Jens Eller
Summary: In this study, the processes of removing transient liquid water in the FF channels and GDLs were visualized and quantified using subsecond in situ X-ray tomographic microscopy (XTM). Time-resolved desaturation profiles were analyzed for three commercially available GDLs with different substrate dimensions, and saturation-dependent effective diffusivities were determined through numerical simulations and cluster connectivity analysis. Characteristic drying phases were identified through HFR curves and confirmed with XTM imaging results. This research provides fundamental understanding of the desaturation dynamics in polymer electrolyte fuel cells (PEFCs) and enables the optimization of GDL substrates and gas purge protocols accordingly.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Editorial Material
Environmental Sciences
Olaf Kolditz, Diederik Jacques, Francis Claret, Johan Bertrand, Sergey V. Churakov, Christophe Debayle, Daniela Diaconu, Kateryna Fuzik, David Garcia, Nico Graebling, Bernd Grambow, Erika Holt, Andres Idiart, Petter Leira, Vanessa Montoya, Ernst Niederleithinger, Markus Olin, Wilfried Pfingsten, Nikolaos I. Prasianakis, Karsten Rink, Javier Samper, Istvan Szoeke, Reka Szoeke, Louise Theodon, Jacques Wendling
Summary: Data science has become an important tool in various scientific and industrial fields, disrupting research methods. Machine learning methods have been developed to accelerate numerical simulations and applied to nuclear waste management. The challenge now is integrating multi-chemical-physical, coupled processes, multi-scale and probabilistic simulations in Digital Twins (DTw) to predict the performance of physical systems. The development of DTw concepts for geological systems in radioactive waste management is particularly challenging due to complexities and uncertainties at varying time and spatial scales.
ENVIRONMENTAL EARTH SCIENCES
(2023)
Article
Chemistry, Physical
Michael Striednig, Adrian Mularczyk, Wenmei Liu, Dirk Scheuble, Magali Cochet, Pierre Boillat, Thomas J. Schmidt, Felix N. Buechi
Summary: Evaporative cooling has the potential to reduce the volume and cost of polymer electrolyte fuel cells, and simplify the structure of bipolar plates. This study provides experimental evidence of its feasibility by analyzing its evaporation behavior, cooling power, internal humidification, electrochemical performance and operational stability.
JOURNAL OF POWER SOURCES
(2023)
Article
Biochemistry & Molecular Biology
Tobias Jaeger, Athanasios Mokos, Nikolaos I. Prasianakis, Stephan Leyer
Summary: Membrane distillation (MD) is a thermal separation process operated below boiling point. Current research focuses on improving the performance of MD modules by studying the membrane structure and underlying mechanisms. Using realistic 3D membrane geometries obtained from X-ray computed tomography, the interaction between liquid and gas phase with the porous membrane material was investigated. The influence of different microstructures on water droplets and the air-water interface within the membrane were also studied.
Article
Nanoscience & Nanotechnology
Kinanti Aliyah, Christian Prehal, Justus S. Diercks, Natasa Diklic, Linfeng Xu, Secil Uensal, Christian Appel, Brian R. Pauw, Glen J. Smales, Manuel Guizar-Sicairos, Juan Herranz, Lorenz Gubler, Felix N. Buchi, Jens Eller
Summary: A method using small-angle X-ray scattering (SAXS) is proposed to quantify the presence of liquid water in polymer electrolyte fuel cell (PEFC) catalyst layers (CLs). The method is validated through wetting experiments and allows for interpretation of the measured SAXS data to derive the most probable wetting mechanism in a flow cell electrode.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Tobias Jager, Jemp Keup, Nikolaos I. Prasianakis, Stephan Leyer
Summary: In this paper, we study the liquid entry pressure and liquid-gas interface shape of a hydrophobic pillar-pore structure. We theoretically analyze the constant mean curvature problem and derive an analytical expression for the liquid entry pressure. We also compare our theoretical findings to multiphase lattice Boltzmann simulations and find agreement, validating our model.
Article
Nanoscience & Nanotechnology
Carl Cesar Weber, Jacob A. Wrubel, Lorenz Gubler, Guido Bender, Salvatore De Angelis, Felix N. Buchi
Summary: To decarbonize crucial industries, it is essential to reduce the cost and scale up the electrolyzer technologies. A key factor is to decrease the price and scarcity of the iridium-based catalyst used in polymer electrolyte water electrolysis. The study focuses on understanding the relationship between the interface of the porous transport layer and the catalyst layer to optimize catalyst utilization.
ACS APPLIED MATERIALS & INTERFACES
(2023)
