Article
Mechanics
H. K. Moffatt, Howard Guest, Herbert E. Huppert
Summary: The behavior of a viscous drop squeezed between two horizontal planes is analyzed through theory and experiment. The theory predicts the growth of the drop radius over time with a power law of t(1/8) when the squeezing force is constant and surface tension is neglected. The experimental results show that the evolution of the drop tends towards a stable circular shape when surface tension is taken into account.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Katarzyna N. Kowal
Summary: The study demonstrates a novel instability in unconfined viscous bands or free-surface flows, known as viscous banding instabilities. Unlike the Saffman-Taylor instabilities in porous media, these instabilities are driven by a viscosity contrast and do not require confinement like in a Hele-Shaw cell. The main difference lies in the driving mechanisms, with Saffman-Taylor instabilities driven by dynamic pressure gradients and viscous banding instabilities driven by hydrostatic pressure gradients related to slope discontinuities.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Geosciences, Multidisciplinary
Xiaolong Geng, Michel C. Boufadel, Hailong Li, Viravid Na Nagara, Kenneth Lee
Summary: Groundwater mixing dynamics are crucial for biogeochemical cycling in shallow wetlands. This study investigated the effects of evaporation and local heterogeneity on mixing dynamics using groundwater simulations. The results show that evaporation causes upwelling of groundwater and solutes to the surface, leading to higher solute concentrations near the surface. Mapping of flow topology reveals spatially varied mixing patterns along preferential flow pathways due to local heterogeneity. These findings have implications for biogeochemical processes in wetlands.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Zhongyuan Xu, Jayaram Hariharan, Paola Passalacqua, Elisabeth Steel, Austin Chadwick, Chris Paola, Anner Paldor, Holly A. Michael
Summary: This study investigates the vulnerability of coastal deltaic aquifers to seawater intrusion, contamination, and groundwater abstraction, as well as the impact of surface deposition changes on the distribution and transport of groundwater solutes. By simulating groundwater flow and solute transport under different contamination scenarios, the research reveals that the vulnerability of deltaic aquifers to seawater intrusion is correlated with sand fraction, and vertical transport of contaminants is influenced by channel stacking patterns.
WATER RESOURCES RESEARCH
(2022)
Article
Engineering, Environmental
Theo S. Sarris, Allanah Kenny, David M. Scott, Murray E. Close
Summary: This study investigates how the detection probability of a groundwater monitoring network is affected by aquifer spatial heterogeneity and dispersion characteristics. The results show that aquifer dispersivity is the dominant parameter for network performance, with more dispersive transport conditions resulting in higher detection rates. Additionally, increasing aquifer heterogeneity and decreasing spatial continuity also lead to higher detection rates, although this effect is diminished for larger networks. Furthermore, statistical anisotropy has no significant impact on the network performance.
Article
Mechanics
Oleg A. Logvinov
Summary: The renowned problem of viscous fluid displacement by a less viscous one in a Hele-Shaw cell is considered in this study. Both fluids exhibit non-Newtonian properties with power-law viscosity dependence. A unified approach is used to derive averaged two-dimensional equations of motion, and linear stability analysis of the radial interface is conducted with a new key idea of characteristic size selection even without stabilizing factors.
Article
Mechanics
Haozhe Su, Chunxi Li, Dan Li, Xuemin Ye
Summary: The study investigates the enhanced spreading and internal diffusion of self-rewetting fluids laden with surfactant and medicine on a hot liquid film. The results show that self-rewetting fluids enhance spreading positively but hinder diffusion on high-viscosity mucus. Medicine absorption is still increased with self-rewetting fluids even in hindered spreading scenarios.
Article
Mechanics
Matheu Broom, Geoff R. Willmott
Summary: Eye-catching shapes are produced when water drops land vertically and spread on horizontal surfaces with micropillars arranged in regular square arrays. The positions of protrusions and fingers are often determined by the microstructure design and may be produced repeatably, which suggests possible manufacturing and analytical applications.
Article
Mechanics
Vandita Sharma, Hamirul Bin Othman, Yuichiro Nagatsu, Manoranjan Mishra
Summary: Through numerical computations and experimental studies, miscible viscous fingering (VF) in an annulus is examined, showing contrast to classical radial VF and instability of a straight displaced slice. The persistence of VF in a miscible annular ring is observed, with variance as a non-monotonic function indicating interaction of two fronts, pressure fingers growing faster than concentration fingers. The variation of finger length with flow rate depends on the amount of more viscous fluid in the annulus, with critical parameters for instability related to viscosity contrast and sample amount.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Water Resources
Ryan G. G. Tigera, Whitney L. L. Benson, David C. C. Mays
Summary: In situ groundwater remediation often involves injecting a chemical or biological amendment as an aqueous solution into a contaminated groundwater aquifer. This study demonstrates that by heating the injected water, the plume spreading of the amendment is enhanced, resulting in elongated plume perimeters and consistent plume areas. Experimental results show that the plume perimeter increased by 47% when determined by binary image analysis or 56% when determined by morphological image analysis. Therefore, heating the injected water can effectively enhance the miscible plume spreading in porous media.
Article
Water Resources
Lucas Mejia, Miguel Mejia, Chiyu Xie, Yujing Du, Abdullah Sultan, Kishore K. Mohanty, Matthew T. Balhoff
Summary: The study found that the presence of low viscosity irreducible water may result in an unstable displacement of medium viscosity oil by high viscosity aqueous solution at small flooding velocities.
ADVANCES IN WATER RESOURCES
(2021)
Article
Polymer Science
Alan Beteta, Ken S. Sorbie, Arne Skauge
Summary: This paper extends the modelling of immiscible viscous fingering to simulate experimental floods and explains the surprising observation of high incremental oil recoveries using polymer injection. The simulations successfully reproduce the observed finger patterns and oil bank formation, indicating the importance of both the viscosity and crossflow mechanisms in increasing oil displacement. The results contribute to a better understanding and prediction of oil recovery in porous media.
Article
Mechanics
Priya Verma, Vandita Sharma, Manoranjan Mishra
Summary: This study provides numerical insights into the radial displacement of two viscously stable reactants undergoing an infinitely fast chemical reaction, expanding the numerical knowledge of the interaction between chemical reaction and hydrodynamic instability. By calculating the onset time of instability and dividing the time domain into stable and unstable zones, the characteristics of reactants in terms of flow stability can be characterized. The dependence of the onset time of instability on the mobility ratio and the Peclet number is obtained, and the length of the fingers in the unstable zone is found to be dependent on the sign of the mobility ratio.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Edward M. Hinton, Apoorv Jyoti
Summary: This study investigates the axisymmetric displacement of an ambient fluid by a second input fluid of lower density and lower viscosity in a horizontal porous layer. The results show that when the fluids have been segregated vertically by buoyancy, the flow becomes self-similar, with the input fluid preferentially flowing near the upper boundary. It is also found that this axisymmetric self-similar flow is stable to angular-dependent perturbations for any viscosity ratio.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Fluids & Plasmas
Jiayu Li, Harishankar Manikantan
Summary: The study demonstrates the stabilizing effect of surface rheology on interfacial instabilities, but the impact of surface rheological stresses on the Saffman-Taylor instability remains unknown. The presence of typical surface viscous surfactants is predicted to result in quantitative changes in the system.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Engineering, Geological
Alessandra Bonazzi, Birendra Jha, Felipe P. J. de Barros
Summary: Geomechanical parameters can affect the flow field and concentration distribution of solutes, while the loading frequency also plays a crucial role in regulating the temporal dynamics of the concentration field.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Xiaoxi Zhao, Birendra Jha
Summary: This study presents a computational framework to understand the impact of plastic deformation on induced fault slip events. Results show that a poroplastic reservoir exhibits larger vertical deformation and delayed slip compared to a poroelastic reservoir, and a reservoir with a smaller modulus than the caprock displays a larger vertical displacement and an earlier onset of both plastic failure and fault slip.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
Deepak K. Tiwari, Birendra Jha, Bhaskar Kundu, Vineet K. Gahalaut, Naresh K. Vissa
Summary: The study suggests that seismicity rate in Delhi region is influenced by factors such as anthropogenic groundwater pumping and seasonally controlled hydrological loading cycle. The stability of basement faults is regulated by both hydro-mechanical factors, which in turn affect anthropogenic seismic activity in the region.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Geological
Saro Meguerdijian, Birendra Jha
Summary: This study quantifies subsurface leakage dynamics of fluids, such as CO2, along faults using a coupled multiphase flow-geomechanics-fault slip simulator. It shows that leakage is non-trivially coupled to induced seismicity and multiphase flow along faults due to the effect of fault dip. The direction of gas and liquid phase leakage is determined by slip propagation and buoyancy vector, both of which depend on fault dip.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2021)
Article
Green & Sustainable Science & Technology
Fangning Zheng, Atefeh Jahandideh, Birendra Jha, Behnam Jafarpour
Summary: This study presents an optimization framework for geologic CO2 storage under geomechanical risks, using coupled flow-geomechanics simulations to quantify risks and make optimal decisions. The results show that optimal decisions may differ when geomechanical risks are considered compared to simulations that only focus on flow dynamics.
INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
(2021)
Article
Public, Environmental & Occupational Health
Seth G. Benzell, Avinash Collis, Christos Nicolaides
Summary: Amid the COVID-19 pandemic, the United States failed to achieve efficiency in implementing social distancing policies, leading to an increase in crowding and visitation at public locations. The rationing of public spaces did not prioritize gatherings with better benefits-to-transmission risk ratios, resulting in a lack of desired outcomes.
Article
Environmental Sciences
Sandro Andres, Marco Dentz, Luis Cueto-Felgueroso
Summary: This study investigates the nonequilibrium effects in coupled flow and deformation in fractured media, revealing the limitations of classical DPP formulations. It provides insights into the drainage and displacement scalings to be expected in highly heterogeneous fractured porous media and identifies expected behaviors regarding flow and deformation in fractured aquifers and reservoirs. The theoretical predictions from the multirate DPP model and high-fidelity models agree, even in highly heterogeneous matrix-fracture systems, accurately reproducing observed nonequilibrium effects.
WATER RESOURCES RESEARCH
(2021)
Article
Mathematics, Interdisciplinary Applications
Marc Santolini, Christos Ellinas, Christos Nicolaides
Summary: Engineering projects often face delays, with perturbations in single activities potentially impacting up to 4 downstream activities, leading to large perturbation cascades. Perturbation clustering significantly affects overall project delays, with high reach nodes in poorly performing projects potentially causing the largest cascades, while low reach nodes in well-performing projects result in localized cascades.
Article
Physics, Fluids & Plasmas
A. Bonazzi, M. Morvillo, J. Im, B. Jha, F. P. J. de Barros
Summary: This study investigates the impact of field heterogeneity and viscosity contrast on the transport behavior of an inert solute in a two-dimensional flow field through high-resolution numerical simulations. The results show that viscosity contrast has a significant impact on mixing at early times, while permeability heterogeneity reduces the peak concentration at a control plane. The study provides insights into the interaction between fingering, channeling, and stagnation, as well as the description of the solute cloud distribution function.
PHYSICAL REVIEW FLUIDS
(2021)
Review
Immunology
Pinelopi Konstantinou, Katerina Georgiou, Navin Kumar, Maria Kyprianidou, Christos Nicolaides, Maria Karekla, Angelos P. Kassianos
Summary: Positive attitudes and frequent discussions within social networks can increase vaccination uptake, while hesitation from family and friends may decrease it. Homophily, especially in terms of race and ethnicity, plays a significant role in shaping vaccination attitudes and behaviors within social networks.
Article
Physics, Applied
Mamta Jotkar, Luis Cueto-Felgueroso
Summary: The article explores a particle separation technique based on diffusiophoresis using numerical simulations, which efficiently drives particle motion through manipulation of solute gradients. By analyzing fluid dynamics and solute gradients, selective separation and characterization of particles based on size and surface charge can be achieved. The efficiency of particle separation can be improved by controlling diffusiophoretic mobility, solute Peclet number, and imposed solute gradient, with diffusioosmosis having either enhancing or inhibiting effects depending on solid surface charge.
PHYSICAL REVIEW APPLIED
(2021)
Article
Environmental Sciences
Sandro Andres, David Santillan, Juan Carlos Mosquera, Luis Cueto-Felgueroso
Summary: Enhanced Geothermal Systems (EGS) can promote sustainable development by providing a green energy supply. However, hydraulic stimulation is often required to improve fluid flow and energy efficiency. This study uses numerical simulations to evaluate the seismic risk associated with hydraulic stimulation and finds that it is not only related to induced seismicity but can also cause a decline in reservoir temperature.
Article
Mechanics
Alessandra Bonazzi, Birendra Jha, Felipe P. J. de Barros
Summary: The impact of viscosity and density contrasts on the transport dynamics of miscible flowing fluids in a porous medium under different initial conditions is investigated. The study shows that the initial shape of the source distribution and the intensity of the background flux have an influence on the temporal evolution of the spreading and mixing processes. It is found that the viscosity of the solute affects the rates of mixing, and the effects of horizontal viscous fingering dominate over gravitational fingering at higher background flux. The computational analysis also reveals a non-trivial relationship between mixing and the length of the plume's interface under fingering instabilities. Finally, the study demonstrates the interaction between a stratified permeability field and these instabilities, and how it affects the transport behavior of the plume.
JOURNAL OF FLUID MECHANICS
(2023)
Correction
Social Sciences, Mathematical Methods
Christos Ellinas, Christos Nicolaides, Naoki Masuda
JOURNAL OF COMPUTATIONAL SOCIAL SCIENCE
(2022)
Article
Social Sciences, Mathematical Methods
Christos Ellinas, Christos Nicolaides, Naoki Masuda
Summary: Successful on-time delivery of projects is crucial in solving major societal challenges, but projects are difficult to deliver successfully due to their complexity and susceptibility to cascading failures. Research has found that the temporal properties of projects are more relevant than structural properties in preventing large-scale cascading failures.
JOURNAL OF COMPUTATIONAL SOCIAL SCIENCE
(2022)
