Article
Mechanics
Thomas Le Reun, Duncan R. Hewitt
Summary: This study investigates convection in a horizontal layer consisting of a fluid-saturated porous bed overlain by an unconfined fluid layer. Under specific conditions, strong convection occurs in the system, and the heat flux and average thermal structure can be predicted based on previous results of convection in individual fluid or porous layers.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Shuang Liu, Linfeng Jiang, Cheng Wang, Chao Sun
Summary: The numerical study investigated Rayleigh-Benard convection through random porous media, focusing on Lagrangian dynamics of fluid particles and heat transfer with varying porosities. The interaction between the porous medium and flow structures led to heterogeneous flow patterns, affecting the dynamics of fluid particles. This study also revealed enhanced heat transfer mechanisms in porous-media convection as porosity decreased.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Duncan R. Hewitt
Summary: This study investigates the effect of a series of thin, horizontal, low-permeability layers on convective motion in a two-dimensional porous medium. High-resolution numerical simulations and simple analytical models are used to explore the role of the Omega parameter and reveal a transition from predominantly diffusive to predominantly advective transfer for intermediate Omega values.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Victoria Hamtiaux, Miltiadis V. Papalexandris
Summary: In this study, turbulent thermal convection in mixed porous-pure fluid domains is investigated using direct numerical simulation. The effects of different sizes of the porous medium and heat loading variations on the convective structures and flow patterns are analyzed. Results for flow statistics, Nusselt number, and temperature variations are presented, showing that the large-scale circulation above the porous medium can exhibit single-roll, dual-roll, or intermediate states depending on the area coverage.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Matthew McCurdy, Nicholas J. Moore, Xiaoming Wang
Summary: This study combines three complementary approaches - linear stability analysis, fully nonlinear numerical simulations, and a coarse-grained model - to determine the circumstances that lead to deep and shallow convection. The research discovers the mechanism of the dynamic shift from shallow to deep convection and constructs a phase diagram that depicts the regions in parameter space giving rise to each convective state.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Fluids & Plasmas
Peter Mora, Gabriele Morra, David A. Yuen
Summary: By studying the accuracy of color-gradient calculations, optimal weights have been found to reduce anisotropic errors and improve the reliability of the method; the improved color-gradient calculation method can be more effectively applied to studies characterizing phenomenology and capillary processes.
Article
Mechanics
Ofer Manor
Summary: The study focuses on calculating steady acoustic flow in porous media and explaining its contribution to mass transport. Various cases of steady acoustic flow are analyzed for different scales, and different methods of handling acoustic flow under different conditions are discussed.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Gerardo Severino
Summary: The study investigates the dispersion mechanism in a porous formation with steady doublet-type flow, using spatial moments to quantify the process. A simple solution is obtained by adopting simplifying assumptions, showing that dispersion in doublet-type flow is significantly larger than in single line flow.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
M. Vynnycky, S. L. Mitchell
Summary: In this paper, the steady-state base flow for natural convection in a vertical porous slab with permeable boundaries is investigated. It is argued that the flow should be two-dimensional instead of one-dimensional, which was proposed in recent work, due to an oversight in the use of the Oberbeck-Boussinesq approximation. Two-dimensional numerical solutions for this flow are obtained using a pressure-temperature formulation, and the results are validated by asymptotic analysis. The paper also briefly discusses the relevance of these findings to other recent work on the stability of convection in porous slabs with permeable boundaries.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Antonio Barletta, Michele Celli, Stefano Lazzari, Pedro V. Brandao
Summary: This study reconsiders the classical Gill's stability problem in a vertical porous slab with impermeable and isothermal boundaries. Instead of studying a homogeneous slab, a three-layer slab with different thermal conductivities is examined. The results show that a flow instability may arise in the sandwiched porous slab when the Rayleigh number is sufficiently large. It is also demonstrated that this instability coincides with that predicted in a previous analysis for a homogeneous porous layer with permeable boundaries in the limiting case of highly permeable external layers compared to the core layer.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
K. S. Bharath, M. R. Flynn
Summary: The experiment investigates the outflow that occurs when a dense fluid plume hits a sloping permeability jump in a two-layered porous medium, with a focus on the dynamics in the intermediate thickness case. Primary gravity currents are arrested when the volume supplied by the plume matches that lost by basal draining, leading to the formation of secondary gravity currents. As the secondary gravity currents propagate left and right, they remobilize the primary gravity currents before being impeded by the sidewall boundaries and leading to layer filling.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
S. S. Gopalakrishnan, B. Knaepen, A. De Wit
Summary: The study investigates the convective finger structures formed by two solutions of different solutes in the gravity field, and analyses the nonlinear dynamics of these buoyancy-driven instabilities. Numerical simulations reveal the evolution of mixing length and the linear relationship between mixing velocity and dynamic density difference.
JOURNAL OF FLUID MECHANICS
(2021)
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
Mechanics
Hamid Emami-Meybodi, Fengyuan Zhang
Summary: This study focuses on the buoyancy-driven stability analysis in a three-dimensional inclined porous medium with a capillary transition zone. The results of linear stability analysis and numerical solutions show that the inclination angle plays a crucial role in the stability of the problem.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Marco De Paoli, Sergio Pirozzoli, Francesco Zonta, Alfredo Soldati
Summary: We conducted large-scale numerical simulations to study Rayleigh-Darcy convection in three-dimensional fluid-saturated porous media. The study revealed that at high Rayleigh-Darcy numbers, the flow is dominated by large columnar structures called megaplumes, which span the entire height of the domain. Near the boundaries, the flow is hierarchically organized with fine-scale structures forming larger-scale supercells. The results also showed a strong correlation between the flow structure in the core of the domain and at the boundaries. The study's findings are important for developing accurate models to predict the large- and fine-scale structure of Rayleigh-Darcy convection in geophysical processes.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Fluids & Plasmas
Irina Stolbova, Scott Backhaus, Michael Chertkov
Article
Mathematics, Applied
Michael K. Rivera, Robert E. Ecke
Article
Engineering, Electrical & Electronic
Yury Dvorkin, Miles Lubin, Scott Backhaus, Michael Chertkov
IEEE TRANSACTIONS ON POWER SYSTEMS
(2016)
Article
Engineering, Electrical & Electronic
Miles Lubin, Yury Dvorkin, Scott Backhaus
IEEE TRANSACTIONS ON POWER SYSTEMS
(2016)
Article
Engineering, Electrical & Electronic
Ian Beil, Ian Hiskens, Scott Backhaus
PROCEEDINGS OF THE IEEE
(2016)
Article
Geochemistry & Geophysics
Charles K. C. Lieou, Eric G. Daub, Robert E. Ecke, Paul A. Johnson
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2017)
Article
Geochemistry & Geophysics
Charles K. C. Lieou, Eric G. Daub, Robert A. Guyer, Robert E. Ecke, Chris Marone, Paul A. Johnson
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2017)
Article
Mechanics
Xuan Zhang, Robert E. Ecke, Olga Shishkina
Summary: In rapidly rotating turbulent Rayleigh-Benard convection with a small Prandtl number fluid in slender cylindrical containers, a boundary zonal flow (BZF) is found to develop near the sidewall, carrying a disproportionate amount of heat transport for Pr < 1 but decreasing abruptly for larger Pr. The BZF is robust and appears in containers of different aspect ratios and over a broad range of Pr and Ra values.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Physics, Fluids & Plasmas
Robert E. Ecke, Xuan Zhang, Olga Shishkina
Summary: Using direct numerical simulations, this study investigates rotating Rayleigh-Benard convection and connects linear wall-mode states with the boundary zonal flow in the geostrophic regime. The data from various sources are quantitatively collapsed, providing insights into the heat transport contributions of the wall modes and boundary zonal flow.
PHYSICAL REVIEW FLUIDS
(2022)
Proceedings Paper
Computer Science, Information Systems
Changhong Zhao, Michael Chertkov, Scott Backhaus
2015 48TH HAWAII INTERNATIONAL CONFERENCE ON SYSTEM SCIENCES (HICSS)
(2015)
Proceedings Paper
Computer Science, Information Systems
Misha Chertkov, Michael Fisher, Scott Backhaus, Russell Bent, Sidhant Misra
2015 48TH HAWAII INTERNATIONAL CONFERENCE ON SYSTEM SCIENCES (HICSS)
(2015)
Article
Automation & Control Systems
Sidhant Misra, Michael W. Fisher, Scott Backhaus, Russell Bent, Michael Chertkov, Feng Pan
IEEE TRANSACTIONS ON CONTROL OF NETWORK SYSTEMS
(2015)
Proceedings Paper
Computer Science, Artificial Intelligence
Boon Ping Lim, Menkes van den Briel, Sylvie Thiebaux, Russell Bent, Scott Backhaus
INTEGRATION OF AI AND OR TECHNIQUES IN CONSTRAINT PROGRAMMING
(2015)
