Article
Mechanics
Yorgos Stergiou, Paszkal Papp, Dezso Horvath, Agota Toth, Kerstin Eckert, Karin Schwarzenberger
Summary: We investigated a convective buoyancy-driven instability that occurs when a denser miscible fluid is injected into a less dense one in a rectilinear geometry. The instability was visualized using shadowgraph technique and quantitative information was obtained using micro-Particle Image Velocimetry. Numerical simulations provided insights into the three-dimensional velocity field. We found that the instability occurs only above a certain Peclet number, depending on the Rayleigh and Schmidt numbers. Scaling laws for the critical time and dimensionless wavelength of the instability were proposed, showing their dependence on Pe and Ra. The interaction of the instability vortices with each other and the geometry boundaries was also investigated.
Article
Oceanography
Qiming Sun, Maosheng Gao, Zhang Wen, Guohua Hou, Xianzhang Dang, Guangming Zhao
Summary: This study simulated the impact of saltwater lakes formed after a storm surge on coastal aquifers. The results show that the total dissolved solids and water level of saltwater lake are subject to constant changes due to evaporation. Smaller vertical hydraulic conductivity leads to less saline infiltration into the aquifer but a greater amount of salt precipitates.
CONTINENTAL SHELF RESEARCH
(2023)
Article
Geochemistry & Geophysics
Jiannan Wang, Sebastian Uhlemann, Shawn Otto, Brian Dozier, Kristopher L. Kuhlman, Yuxin Wu
Summary: By conducting in situ geophysical monitoring and numerical simulations, this study investigated the brine migration during salt heating, providing a deeper understanding of the coupled thermal-hydrological-mechanical processes in salt and its significance for the safe disposal of radioactive waste.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Engineering, Civil
K. R. Moore, H. M. Hollander, A. D. Woodbury
Summary: Subsurface mineral dissolution problems are complex and difficult to model accurately. Controlled experimental problems combined with numerical models can enhance understanding of mineral dissolution and improve predictive capabilities.
JOURNAL OF HYDROLOGY
(2021)
Article
Mechanics
Marie-Pierre C. Delisle, Yeulwoo Kim, Ryan S. Mieras, Timu W. Gallien
Summary: This study numerically investigates sheet flow driven by a near-breaking transient wave using the SedFoam model, and reveals that intense sediment suspension trailing the wave crest generates stable density stratification, reducing bed shear stress. The buoyant flux dominates turbulent kinetic energy dissipation after the passing of the wave crest. The study also identifies different log-law regimes for the instantaneous upper bound of the sheet flow layer under the transient wave, which significantly impacts the near-bed velocity profile.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2022)
Article
Geochemistry & Geophysics
Weiwei Zhu, Zhiqiang Chen, Xupeng He, Zhiguo Tian, Moran Wang
Summary: Hydraulic fracturing is widely used in stimulating unconventional reservoirs. This study investigates the impact of different factors on the initiation and propagation of hydraulic fractures using a numerical simulation method. The results show that factors such as injection rate, fluid viscosity, in situ stress, formation permeability, and bond strength heterogeneity all have significant effects on fracture initiation and complexity.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Weiwei Zhu, Zhiqiang Chen, Xupeng He, Zhiguo Tian, Moran Wang
Summary: In this study, a discrete element-lattice Boltzmann method was used to simulate the hydro-mechanical behavior in hydraulic fracturing. Different influential factors were considered, and their impacts on the initiation and propagation of hydraulic fractures were evaluated. It was found that factors such as injection rates, heterogeneity of rock strengths, and the presence of natural fractures significantly influenced the complexity of generated fractures.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Mechanics
Julian Brosda, Michael Manhart
Summary: This study presents a high-resolution dataset of turbulent flow in a semifilled pipe using direct numerical simulation, revealing some flow phenomena that have not been reported previously, such as the presence of an inner secondary cell in the mixed corner. Additionally, the study demonstrates distributions of the complete Reynolds stress tensor and the mechanism for generating mean streamwise vorticity.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Chemical
Matthieu Constant, Nathan Coppin, Frederic Dubois, Riccardo Artoni, Jonathan Lambrechts, Vincent Legat
Summary: This paper investigates the density sorting of grains using water jigging by conducting experiments and comparing numerical results for two initial bed configurations. The vertical composition of the deposit is estimated after different numbers of water pulses to show the sorting evolution over time. Key parameters are varied numerically to determine the sensitivity of the process.
Article
Engineering, Chemical
Monica Tirapelle, Andrea C. Santomaso, Patrick Richard, Riccardo Artoni
Summary: This paper experimentally investigates density-difference-driven segregation in a range of density ratios and heavy particle concentrations, proposing a continuum approach to model the process. The model is validated by comparison with experimental findings, successfully predicting density-driven segregation at different density ratios and volumetric fractions.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Thermodynamics
Kazuto Kuzuu, Shinya Hasegawa
Summary: Thermoacoustic engines have gained increasing interest for their potential use in renewable energy systems. This study examined the heat transfer characteristics of such engines through numerical simulations, determining a model to predict temperature gap at the edge of a regenerator within specific ranges of Reynolds number and nondimensional relaxation time.
APPLIED THERMAL ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Yuntao Liang, Rui Zhou
Summary: The fully coupled THMC model developed in this study analyzes the spontaneous combustion process of underground coal seams, showing that oxygen propagating into the coal seams causes coal to heat and self-ignite. The pressure difference and coal-oxygen reaction heat have significant effects on promoting coal temperature, while the activation energy has a slight effect on oxygen consumption rate and concentration.
Article
Mechanics
Ruijie Zhao, You Zhou, Desheng Zhang, Xiongfa Gao
Summary: The hydraulic transport of coarse particles in a vertical pipe is simulated and the influences of different fluid-particle interaction mechanisms on the liquid-solid flow are estimated. The role of lift force is found to be significant, while pressure gradient force and virtual mass force have marginal effects. The interaction between particles and turbulence is complex and should be considered in the simulation.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Engineering, Mechanical
Yiyu Lu, Shan Huang, Zhaolong Ge, Zhe Zhou, Zhengyang Song
Summary: In this study, a fully coupled fluid flow-DEM method is used to investigate the propagation characteristics of hydraulic fracture in coal with natural planes. Numerical simulations are conducted to analyze the impact of the approaching angle of natural planes, in-situ geo-stress, and fluid flow injection rate on fracture propagation behavior and breakdown pressure. The results show that the presence of weak natural planes with large approaching angles can facilitate the development of complex fracture networks in coal. The intersection mode of hydraulic fracture and natural planes in coal is more sensitive to different approaching angles compared to other rock masses. Moreover, distinct injection rates and in-situ stress difference of natural planes also play a crucial role in determining hydraulic fracture morphology and its interaction mode with natural planes. The findings of this study may provide a numerical reference for optimizing the design of hydraulic fracturing in coal.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Mechanics
Peilu Hu, Pengfei Wang, Li Liu, Xiaodong Ruan, Lingjie Zhang, Zhongbin Xu
Summary: A Tesla valve is a passive check valve that has no-moving parts and can be used for fluid control in various engineering fields. This study investigates the diode characteristics of Tesla valves by changing their geometric parameters and finds that the optimal angle for Tesla valves is 70-80 degrees.
Article
Environmental Sciences
Oliver S. Schilling, Peter G. Cook, Pauline F. Grierson, Shawan Dogramaci, Craig T. Simmons
Summary: This study investigated the controls for SW-GW-vegetation interactions along intermittent rivers and ephemeral streams through numerical experiments. Results showed that infiltration is controlled by ephemerality and hydraulic conductivity (K), while transpiration is influenced by a complex interplay between ephemerality, hydraulic properties, and vegetation.
WATER RESOURCES RESEARCH
(2021)
Article
Environmental Sciences
Martyna Glodowska, Magnus Schneider, Elisabeth Eiche, Agnes Kontny, Thomas Neumann, Daniel Straub, Michael Berg, Henning Prommer, Benjamin C. Bostick, Athena A. Nghiem, Sara Kleindienst, Andreas Kappler
Summary: High concentrations of arsenic in groundwater pose a worldwide health threat, with microbial processes playing a key role in regulating dissolved arsenic levels. Research suggests that organic carbon turnover has a significant impact on the formation and dissolution of iron minerals, indirectly affecting arsenic mobility.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Emiliano Stopelli, Vu T. Duyen, Henning Prommer, Martyna Glodowska, Andreas Kappler, Magnus Schneider, Elisabeth Eiche, Alexandra K. Lightfoot, Carsten J. Schubert, Pham K. T. Trang, Pham H. Viet, Rolf Kipfer, Lenny H. E. Winkel, Michael Berg
Summary: In a high-arsenic aquifer near Hanoi, stable isotope analysis and hydrogeochemical parameters revealed the role of methane cycling and DOC infiltration in arsenic heterogeneity. Methanogenesis and methane oxidation were found to actively contribute to the distribution of arsenic in groundwater, highlighting the importance of these processes in high-arsenic aquifers.
Article
Geochemistry & Geophysics
Alyssa Barron, Jing Sun, Stefania Passaretti, Chiara Sbarbati, Maurizio Barbieri, Nicolo Colombani, James Jamieson, Benjamin C. Bostick, Yan Zheng, Micol Mastrocicco, Marco Petitta, Henning Prommer
Summary: Arsenic is a harmful and widespread groundwater contaminant. Laboratory-scale studies have found that the joint addition of nitrate and Fe(II) can form magnetite and reduce dissolved arsenic concentrations in polluted coastal aquifers. Phosphate concentrations and salinity do not affect the remediation efficiency of this method.
APPLIED GEOCHEMISTRY
(2022)
Article
Environmental Sciences
Wenhao Wei, Athena Nghiem, Rui Ma, Ziyong Sun, Xulong Gong, Aiguo Zhou, Henning Prommer
Summary: The study found significant variation in iodine concentrations in groundwater in Northern Jiangsu, with high levels mainly found in marine plains and flood sediments of the Old Yellow River. Marine or lagoonsfacies sediments were identified as the most likely source of iodine, while the flood sediments of the Old Yellow River were deemed unlikely as a source.
JOURNAL OF CONTAMINANT HYDROLOGY
(2021)
Article
Engineering, Environmental
Rui Tang, Haiping Luo, Henning Prommer, Zhengbo Yue, Wei Wang, Kuizu Su, Zhen-Hu Hu
Summary: The extensive use of organoarsenic feed additives has led to the occurrence of organoarsenicals in livestock wastewater and anaerobic wastewater treatment systems. The long-term impact of roxarsone on Anaerobic Granular Sludge (AGS) activity has been investigated in this study, revealing a significant reduction in methane production initially, with eventual restoration. The study also found that roxarsone exposure stimulated the excretion of extracellular polymeric substances and surface spalling of AGS, while altering microbial pathways and inhibiting specific methanogen species before full restoration of methane production.
Article
Engineering, Environmental
Alexandra K. Lightfoot, Matthias S. Brennwald, Henning Prommer, Emiliano Stopelli, Michael Berg, Martyna Glodowska, Magnus Schneider, Rolf Kipfer
Summary: Groundwater contamination of geogenic arsenic remains a global health threat, particularly in southeast Asia, where a prominent correlation between high arsenic concentrations and methane has been observed. This study analyzed the gas dynamics in an arsenic-contaminated aquifer and found a progressive depletion of atmospheric gases alongside an increase in methane. It was hypothesized that the formation of a free gas phase mainly composed of methane significantly reduces water renewal and impacts groundwater flow. Another hypothesis suggests the potential transport of helium from an adjacent aquitard into the methane producing zone. These findings provide a plausible explanation for the correlation between high arsenic and methane concentrations and the patchy distribution of dissolved arsenic in contaminated aquifers.
Article
Environmental Sciences
Ying Liang, Rui Ma, Athena Nghiem, Jie Xu, Liansong Tang, Wenhao Wei, Henning Prommer, Yiqun Gan
Summary: The occurrence of excessive ammonium in groundwater is a global threat to human and aquatic ecosystem health. Identifying the sources of groundwater ammonium is crucial for effective mitigation strategies. In this study, a novel approach combining machine learning and fluorescence analysis was used to distinguish the sources of ammonium in a multi layer aquifer.
ENVIRONMENTAL POLLUTION
(2022)
Article
Engineering, Environmental
Sarah Koopmann, Henning Prommer, Thomas Pichler
Summary: This study investigates the release of molybdenum (Mo) in dolomitic aquifers during managed aquifer recharge (MAR). The findings suggest that Mo is associated with easily soluble sulfurized organic matter present in intercrystalline spaces of dolomites or directly incorporated within dolomite crystals. The injection of oxygenated water causes the oxidation of pyrite and dissolution of dolomite, leading to the release of Mo.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Ilka Wallis, John Hutson, Greg Davis, Rai Kookana, John Rayner, Henning Prommer
Summary: This study developed and evaluated conceptual and numerical models to determine the migration ability of PFAS in the vadose zone under real field conditions. The results show that climate-driven physical flow processes have a dominant control on PFAS retention, with physico-chemical retention mechanisms adding further to PFAS retention.
Article
Metallurgy & Metallurgical Engineering
Pablo Ortega-Tong, James Jamieson, Benjamin C. Bostick, Andy Fourie, Henning Prommer
Summary: Electrokinetic in situ leaching (EK-ISL) is a novel mining technology that aims to recover copper from orebodies without physical excavation, thereby reducing the environmental impact of mining. The formation of secondary layers is a critical issue affecting the efficiency of copper sulphide leaching. This study characterized the formation of secondary leaching products under EK-ISL conditions and found that the sustained dissolution of polysulphides during leaching exposes new mineral surfaces, leading to enhanced copper recovery.
Editorial Material
Green & Sustainable Science & Technology
Henning Prommer
Summary: The mining of rare earth elements is crucial for decarbonizing our economies, but it has a negative environmental impact. The use of electrokinetics offers a more efficient extraction method with reduced environmental consequences.
NATURE SUSTAINABILITY
(2023)
Article
Engineering, Environmental
Sarah Koopmann, Henning Prommer, Adam Siade, Thomas Pichler
Summary: The mobility of molybdenum in groundwater systems has been studied using a comprehensive hydrochemical dataset collected during a multi-cycle aquifer storage and recovery test. It was found that the initial mobilization of molybdenum occurs through a series of reactions, involving pyrite oxidation, dolomite dissolution, and the release of molybdenum bound to soluble sulfurized organic matter. Once released, molybdenum mobility is primarily controlled by pH-dependent surface complexation reactions and the capture by iron sulfides.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Pablo Ortega-Tong, James Jamieson, Laura Kuhar, Leon Faulkner, Henning Prommer
Summary: In situ recovery (ISR) is an alternative mining method that can reduce landscape damage, eliminate tailings, dams, and waste rock, and minimize energy consumption and carbon emissions. However, the application of ISR to metals other than uranium is limited due to low hydraulic conductivity and heterogeneity of orebodies. Laboratory experiments and a reactive transport model were used to investigate the main controls for copper recovery in a specific setup. The results showed a mineralogical control exerted by the copper mineral composition and a dependence on the supplied lixiviant.
ACS ES&T ENGINEERING
(2023)
Article
Chemistry, Analytical
Adam J. Siade, Benjamin C. Bostick, Olaf A. Cirpka, Henning Prommer
Summary: The evolution of groundwater quality is influenced by complex interactions between physical transport and biogeochemical reactions. Identifying and quantifying processes that control the overall system behavior is crucial for experimentation and monitoring. Process-based computer models are underutilized in understanding subsurface biogeochemistry but provide a valuable tool for quantitatively testing hypothetical combinations of complex processes.
ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
(2021)