Article
Materials Science, Multidisciplinary
Antonio Baldi, Michele Brun, Giorgio Carta
Summary: The proposed design of a novel three-dimensional porous continuous solid with negative Poisson's ratio exhibits cubic symmetry and moderate degree of anisotropy. The directional dependence of Poisson's ratio and Young's modulus shows multidirectional auxeticity. Numerical results are validated by experimental results from Digital Image Correlation data, with potential for large-scale industrial production.
MECHANICS OF MATERIALS
(2022)
Article
Mechanics
Mohammad Azis Mahardika, Yun She, Tomotaka Koe, Anindityo Patmonoaji, Muhammad Nasir, Shintaro Matsushita, Tetsuya Suekane
Summary: This study visualized the interface stability of vertical displacement in porous media and derived two stability criteria. The results showed that Dumore's stability criterion is more appropriate for predicting interface stability. The transition between stable and unstable displacements was observed, and similar phenomena in two-dimensional experiments were observed in three dimensions.
Article
Mechanics
Eslam Ezzatneshan, Reza Sadraei
Summary: This study investigates the effects of vibration on droplet dynamics inside a three-dimensional porous medium. The results show that contact angle significantly affects the volume and duration of droplet drainage. Hydrophilic pores hinder droplet drainage and resist vibration, while a hydrophobic surface leads to quicker drainage. The study also finds that increasing the vibration frequency can enhance droplet separation and improve drainage.
Article
Mathematics, Applied
Julian Fischer, Daniel Matthes
Summary: Various degenerate diffusion equations exhibit a waiting time phenomenon where the solution's support may not expand for a certain amount of time depending on the initial datum's flatness at the boundary. This phenomenon is captured by Lagrangian discretizations and numerical simulations show its clear visibility even in relatively coarse discretizations.
SIAM JOURNAL ON NUMERICAL ANALYSIS
(2021)
Article
Water Resources
Xiangjuan Yang, Qian Shao, Hussein Hoteit, Jesus Carrera, Anis Younes, Marwan Fahs
Summary: This study investigates three-dimensional natural convection processes in heterogeneous porous media using a meshless Fourier series approach. By considering a large-scale Rayleigh number to account for heterogeneity, it is found that the method is highly accurate for 3D natural convection problems.
ADVANCES IN WATER RESOURCES
(2021)
Article
Environmental Sciences
Wei Li, John T. Germaine, Herbert H. Einstein
Summary: Understanding the formation and evolution of wormholes in porous media is crucial for various natural and industrial processes. Through core flood tests, it is found that the lengths of wormholes follow a power-law distribution, with more short ones than long ones. This statistical nature allows for experimental investigation of wormhole competition in three dimensions. Additionally, the existing wormhole-matrix models underestimate the lengths due to neglected radial flow near the wormhole tip, which is improved by approximating with a Rankine ovoid model.
WATER RESOURCES RESEARCH
(2022)
Article
Physics, Fluids & Plasmas
Denis Volkhonskiy, Ekaterina Muravleva, Oleg Sudakov, Denis Orlov, Evgeny Burnaev, Dmitry Koroteev, Boris Belozerov, Vladislav Krutko
Summary: In this paper, a deep learning architecture is proposed for the reconstruction of three-dimensional porous medium structures from two-dimensional slices. By fitting a distribution based on a given dataset, samples with similar properties are generated. Numerical experiments show that this method achieves good reconstruction results.
Article
Physics, Fluids & Plasmas
Christophe Brouzet, Yves Meheust, Patrice Meunier
Summary: This study investigates the storage of carbon dioxide (CO2) in deep saline aquifers and the resulting convective dissolution instability. Experimental results show a significant discrepancy between the measured growth rate of the instability and theoretical predictions, with the measured rate being one to three orders of magnitude larger. The study suggests that accounting for sub-Darcy-scale flow heterogeneities may be necessary to accurately predict convective dissolution during CO2 subsurface sequestration.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Water Resources
Inga Berre, Wietse M. Boon, Bernd Flemisch, Alessio Fumagalli, Dennis Glaeser, Eirik Keilegavlen, Anna Scotti, Ivar Stefansson, Alexandru Tatomir, Konstantin Brenner, Samuel Burbulla, Philippe Devloo, Omar Duran, Marco Favino, Julian Hennicker, I-Hsien Lee, Konstantin Lipnikov, Roland Masson, Klaus Mosthaf, Maria Giuseppina Chiara Nestola, Chuen-Fa Ni, Kirill Nikitin, Philipp Schadle, Daniil Svyatskiy, Ruslan Yanbarisov, Patrick Zulian
Summary: Flow in fractured porous media has significant impacts on the underground, biological tissues, and man-made materials. Recently, there has been a development of models and numerical methods to explicitly consider the influence of fractures on flow processes. Four benchmark cases were presented to test the capabilities of numerical methods in handling the complexities common to the geometrical structures of fracture networks, with results obtained from 17 numerical methods collected and analyzed.
ADVANCES IN WATER RESOURCES
(2021)
Article
Engineering, Marine
P. Prabu, Abhijit Chaudhuri, S. Murty Bhallamudi, S. A. Sannasiraj
Summary: Sea dikes are used to protect onshore infrastructures from tsunami impact. This study investigated the effects of different types of sea dikes on tsunami impact force through numerical simulations. The results showed that sea dikes with gaps can reduce the impact force, and composite dikes as well as staggered rows of intermittent dikes provide protection.
Article
Physics, Fluids & Plasmas
Zhixin Xia, Qizhi Teng, Xiaohong Wu, Juan Li, Pengcheng Yan
Summary: The proposed method in this study improves accuracy and speed in reconstructing porous media by designing a special template for block matching and porosity control, achieving a 4-6 speedup factor compared to traditional SD methods.
Article
Thermodynamics
Muhammad Nasir, Zijing Li, Mohammad Azis Mahardika, Weicen Wang, Yun She, Kailin Wang, Anindityo Patmonoaji, Shintaro Matsushita, Tetsuya Suekane
Summary: This study investigates the effects of wettability on the drying process of 3D porous media using X-ray micro-tomography. Higher wettability leads to increased capillary pressure and the rearrangement of liquid from large to small pores. Liquid clusters, which are associated with branch clusters, maintain the gas-liquid interfacial area, serving as the evaporation surface. Drying is more intensive in water-wet porous media, while in neutral-wet porous media, there is an early drop in drying rate.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Mechanical
Chaoqun Zeng, Wei Wang, Xuhao Cheng, Rui Zhao, Hailong Cui
Summary: In this study, a high-precision and low-cost method using deep learning is proposed to reconstruct a three-dimensional porous model and analyze the flow state inside porous materials. The method can reveal richer flow states that were previously not addressed, such as flow tracks and movements in three directions. This approach is effective for studying the properties of porous materials, micro-flow states, and detailed parameter simulations.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Mechanics
J. Michel, D. Durante, A. Colagrossi, S. Marrone
Summary: The European H2020 project SLOWD aims to investigate the damping effect of fuel sloshing to reduce the design loads on aircraft wings. In this study, a simplified model was used to examine the sloshing problem of fuel inside wings, and a smoothed particle hydrodynamic model was adopted to evaluate the energy dissipation. The research found that simulating such violent flow is challenging, and comparisons between viscosity and different liquids were also discussed.
Article
Chemistry, Physical
R. Narasimman, Manmohansingh Waldiya, K. Jalaja, Suresh K. Vemuri, Indrajit Mukhopadhyay, Abhijit Ray
Summary: A self-standing and hybrid MoS2/Ni3S2 foam electrocatalyst was prepared for the hydrogen evolution reaction in alkaline medium, showing good performance. The unique surface morphology of Ni3S2 foam resulted from the sulfurization of Ni foam and the dip coating of MoS2 contributed to the formation of this electrocatalyst. The electrocatalyst exhibited excellent stability and performance under HER conditions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Engineering, Chemical
Z. Kanavas, F. J. Perez-Reche, F. Arns, V. L. Morales
Summary: This study aims to describe the spatial distribution of flow in heterogeneous porous media by analyzing the characteristics of the underlying pore structure. Through numerical simulations and graph conceptualization, preferential and stagnant flow regions can be distinguished, and the channelization of flow can be quantified. By analyzing weighted paths and structural similarity, accurate flow paths can be predicted and the flow structure within the pore network can be explained.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Engineering, Chemical
Marco Dentz, Juan J. Hidalgo, Daniel Lester
Summary: This review provides an overview of concepts and approaches for quantifying passive, non-reactive solute mixing in porous media flows. It discusses the interrelated processes of stirring, dispersion, and mixing, and reviews different methods to quantify them. The review also emphasizes the multiscale nature of mixing and its dependence on medium structure and flow conditions.
TRANSPORT IN POROUS MEDIA
(2023)
Editorial Material
Engineering, Chemical
Marco Dentz, Daniel R. Lester, Michel F. M. Speetjens
TRANSPORT IN POROUS MEDIA
(2023)
Article
Environmental Sciences
Ilan Ben-Noah, J. J. Hidalgo, Joaquin Jimenez-Martinez, Marco Dentz
Summary: In this study, the upscaling of pore-scale solute transport in partially saturated porous media at different saturation degrees was investigated. It was found that the interaction between structural heterogeneity, phases distribution, and small-scale flow dynamics leads to complex flow patterns and broad probability distributions of flow. A continuous-time random walk (CTRW) framework was used to upscale and evaluate the transport of diluted solutes, and the results were compared to direct numerical simulations. The analysis showed that the fluid phase saturation, as well as the Peclet number, influenced the advective tortuosity, characteristic length, fraction of immobile region, mean trapping time, trapping length, and trapping frequency.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Marie-Madeleine Stettler, Marco Dentz, Olaf A. A. Cirpka
Summary: Macrodispersion in heterogeneous formations is caused by spatial variability of the velocity field. Differential advection interacts with diffusion to determine effective dispersion, while pure advection is reversible and diffusion is irreversible. We found that the reversibility of macrodispersion is bigger for ensemble dispersion than for effective dispersion, challenging the use of the latter as a metric of mixing.
WATER RESOURCES RESEARCH
(2023)
Article
Water Resources
Laurent Talon, Emma Ollivier-Triquet, Marco Dentz, Daniela Bauer
Summary: Transport processes in the subsurface are strongly influenced by the heterogeneity of the porous structure. The heterogeneity of the permeability field and exchange times have significant impacts on the transient and asymptotic transport regimes. A parametric study is conducted to investigate these impacts and a continuous time random walk (CTRW) model is developed to upscale the transport behaviors.
ADVANCES IN WATER RESOURCES
(2023)
Article
Engineering, Environmental
Ishaan Markale, Maxence Carrel, Dorothee L. Kurz, VeronicaL. Morales, Markus Holzner, Joaquin Jimenez-Martinez
Summary: Internal heterogeneity of biofilms plays a crucial role in enhancing fluid mixing and reactions within porous media, which has significant implications for industrial and environmental applications. This study utilizes advanced imaging techniques to investigate the impact of internal heterogeneity on fluid flow and solute transport in bacterial biofilms. The results show that internal heterogeneity mainly affects intermediate velocities and significantly influences biologically driven reactions. Understanding and considering the internal heterogeneity of biofilms is important for predicting reactivity in bioclogged porous systems.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Daniel R. Lester, Marco Dentz, Prajwal Singh, Aditya Bandopadhyay
Summary: This study compares the transverse macrodispersion in porous media with different conductivity structures under purely advective transport. It is found that porous media with smooth, locally isotropic hydraulic conductivity exhibit zero transverse macrodispersion, while non-smooth or locally anisotropic conductivity fields can generate transverse macrodispersion. These findings provide insights into the mechanisms that govern transverse macrodispersion in groundwater flow.
WATER RESOURCES RESEARCH
(2023)
Article
Physics, Fluids & Plasmas
A. Ganesh, C. Douarche, M. Dentz, H. Auradou
Summary: This paper presents a numerical study on the dispersion of bacteria in a plane Poiseuille flow, modeling the bacteria as active Brownian ellipsoids. The longitudinal and transverse macroscopic dispersion coefficients are determined and their scaling with the Peclet number is studied. Three different regimes are observed: a Taylor dispersion regime at low shear rate, an intermediate active regime with increased longitudinal dispersion and decreased transverse dispersion, and a new Taylor regime with diffusivity determined by molecular diffusion coefficient. The active regime is shown to originate from the increased time taken by particles to diffuse across the channel gap, and the transition to the active regime is delayed by decreasing the channel height.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Stefano Brizzolara, Jean-Paul Mollicone, Maarten van Reeuwijk, Markus Holzner
Summary: In this study, an equation is derived to quantify the local entrainment velocity at multi-scales, providing insights into the turbulent mixing process at different scales.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2023)
Article
Geosciences, Multidisciplinary
Marco Dentz, James W. Kirchner, Erwin Zehe, Brian Berkowitz
Summary: In this study, we investigate anomalous transport in a hydrological catchment system over a 36-year period at kilometer scales. Using spectral analysis, we examine the fluctuation scaling of long-term time series measurements of chloride, a natural passive tracer, for rainfall and runoff. The findings suggest that the scaling behavior can be described by a continuous time random walk (CTRW) based on a power-law distribution of transition times, indicating the presence of two distinct power-law regimes in the overall travel time distribution in the catchment. The CTRW framework provides a means to assess anomalous transport in catchments and its implications for water quality fluctuations.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Ran Holtzman, Marco Dentz, Ramon Planet, Jordi Ortin
Summary: We develop a thermodynamic framework for quasistatic dissipative systems with multiple metastable states by utilizing the return-point memory of cyclic macroscopic trajectories. Using this framework, we analyze and quantify the energy dissipation during quasistatic fluid-fluid displacements in disordered media. Numerical computations reveal that energy dissipation in quasistatic displacements is primarily caused by abrupt changes in the fluid-fluid configuration between consecutive metastable states (Haines jumps), which depend on microstructure and gravity. Comparison with quasistatic experiments helps determine the relative importance of viscous dissipation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Chemistry, Physical
Janis E. Patino, William P. Johnson, Veronica L. Morales
Summary: Experiments and models show that the transport behavior of colloids in subsurface porous media is influenced by surface chemical and physical heterogeneities. Understanding these mechanisms and distribution outcomes is crucial for assessing and controlling groundwater contamination.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Environmental Sciences
Aronne Dell'Oca, Marco Dentz
Summary: In this study, we focus on the upscaling and prediction of ensemble dispersion in two-dimensional heterogeneous porous media, specifically transverse dispersion. We investigate the stochastic dynamics of advective particles in the heterogeneous flow field and find that transverse dispersion exhibits ultraslow diffusion due to the solenoidal character of the flow field. By analyzing particle velocities and orientations through equidistant sampling along particle trajectories obtained from direct numerical simulations, we derive a stochastic model that combines correlated Gaussian noise for transverse motion and a spatial Markov model for particle speeds. We compare the model results with detailed numerical simulations in different heterogeneous porous media.
WATER RESOURCES RESEARCH
(2023)
Article
Multidisciplinary Sciences
Ron Shnapp, Stefano Brizzolara, Marius M. Neamtu-Halic, Alessandro Gambino, Markus Holzner
Summary: This article discusses the significance and universality of turbulent pair dispersion at different scales. By studying the alignment between relative velocity and position vectors, a universal constant of turbulence is revealed. This has important implications for understanding and modeling transport and mixing processes.
NATURE COMMUNICATIONS
(2023)
