Article
Thermodynamics
Govindarao Nammi, Dhrijit Kumar Deka, Sukumar Pati, Laszlo Baranyi
Summary: This study investigates unsteady natural convection heat transfer within a square-shaped porous confinement with four heated cylinders, showing different heat transfer phenomena under different Darcy numbers and Rayleigh numbers. As the Rayleigh number increases, the temperature and flow fields in the enclosure lose symmetry under certain conditions.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Engineering, Chemical
Rached Nciri, Faris Alqurashi, Chaouki Ali, Faouzi Nasri
Summary: This study numerically investigates the hydrodynamic-elastic problem in a double enclosure solar collector, analyzing the effects of hot temperatures, the Rayleigh number, and air pressure on the temperature distribution, velocity distribution, and Nusselt number evolution of a Fe3O4/water nanofluid.
Article
Environmental Sciences
Avihai Tsinober, Uri Shavit, Ravid Rosenzweig
Summary: We numerically investigate the effect of hydrodynamic dispersion on convective dissolution of carbon dioxide in saline aquifers. The transport equations are solved to describe the dissolution process and analyze the influence of dispersion on the wavenumber and dissolution flux. The results show that dispersion decreases the dissolution rate and reduces the finger wavenumber. New empirical scaling laws are developed based on the simulated results to predict the dissolution rate and wavenumber.
WATER RESOURCES RESEARCH
(2023)
Article
Mechanics
Alessandro De Rosis, Giovanni Giustini
Summary: This paper analyzes the flow and heat transfer regimes in Rayleigh-Benard convection with a melting boundary using numerical simulations. The results provide insight into the complex behavior of thermal convection, melting, and fluid dynamics.
Article
Thermodynamics
I Perez-Reyes, A. S. Ortiz-Perez
Summary: Feedback control was applied to investigate conditions for delay of the onset of convection in a viscoelastic Jeffreys fluid layer heated from below. The study found interesting results for fixed Prandtl numbers of 1 and 10, showing that proportional control may not work as expected under certain conditions. An analytical approach using the Galerkin method discussed limits of feedback control in terms of the system parameters, and a numerical analysis was performed to map the space of physical parameters. Results were compared with previous studies, highlighting the importance of small control adjustments.
JOURNAL OF APPLIED FLUID MECHANICS
(2021)
Article
Mechanics
Sebastian Moller, Theo Kaeufer, Ambrish Pandey, Joerg Schumacher, Christian Cierpka
Summary: Turbulent superstructures in horizontally extended three-dimensional Rayleigh-Benard convection flows are investigated in controlled laboratory experiments in water at Prandtl number Pr = 7. The experimental results confirm that the superstructure patterns are an important backbone of the heat transfer.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Jian-Chao He, Yun Bao, Xi Chen
Summary: Direct numerical simulation (DNS) is conducted for non-slip two dimensional (2D) Rayleigh-Benard convection (RBC) with a wide range of Rayleigh number (Ra up to 10^13), Prandtl number Pr 1/4 0.7, and aspect ratio gamma= 1. The thermal dissipation rate shows an evident scaling transition at Ra asymptotic to 10^9. The mean temperature gradient in the thermal boundary layer is the dominant contribution to the transition. The Nusselt number also exhibits the transition at Ra asymptotic to 10^9. Rating: 7/10.
Article
Thermodynamics
Ahmad Shafee, M. Jafaryar, Elham Abohamzeh, Nguyen Dang Nam, Iskander Tlili
Summary: Simulation of swirl flow intensification with a new device inside a pipe was conducted, showing that dispersing hybrid nanopowders can enhance testing fluid characteristics, increase tangential velocity of nanomaterial with rising Re, and thinning the thermal boundary layer near the wall by reducing pitch ratio leads to higher Nu.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Engineering, Mechanical
Xu Zhu, Quan Zhou
Summary: An experimental study of flow structures in turbulent Rayleigh-Bénard convection in annular cells with different aspect ratios and radius ratios was conducted. Different flow states and characteristics were found under different Gamma values, showing that the flow structures exhibit variations with increasing aspect ratios.
ACTA MECHANICA SINICA
(2021)
Article
Thermodynamics
Alessandro Mauro, Michela Ciccolella
Summary: This work focuses on transient natural convection in vertical annuli partially filled with a low Darcy number porous medium. The study uses a validated and stable fully explicit fractional step algorithm to solve the generalized porous medium model. Sensitivity analyses are performed by varying the geometrical features of the cavity and the porous domain, as well as the properties of the porous medium. The results are compared to those obtained without the porous insert to investigate its influence on the transient evolution of the Nusselt number.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2022)
Article
Multidisciplinary Sciences
Pradeep G. Siddheshwar, Mahesha Narayana, David Laroze, C. Kanchana
Summary: In this paper, the Brinkman-Benard convection problem with general boundary conditions is investigated. By using the Maclaurin series, a relatively exact linear stability analysis and a weakly nonlinear stability analysis are performed. Chaos in such systems is studied with great accuracy. The critical Rayleigh number and wave number are obtained, and a generalized Lorenz model for the general boundary condition is derived. The effects of Biot and slip Darcy numbers on the critical Rayleigh number and wave number are discussed.
Article
Mechanics
Shashwat Bhattacharya, Mahendra K. Verma, Arnab Bhattacharya
Summary: A multivariate regression model and a neural network model were developed in this paper to predict the Reynolds number and Nusselt number in turbulent thermal convection. By comparing with earlier models, it was found that the machine-learning models in this work provided the best match with the experimental and numerical results.
Article
Chemistry, Multidisciplinary
Massimo Corcione, Alessandro Quintino
Summary: This study presents a numerical investigation on Rayleigh-Benard convection in a shallow cavity filled with different metal-oxide water-based nanofluids. The dispersion of nanoparticles into the base fluid enhances the stability of the nanofluid layer and determines the conditions for convection onset.
APPLIED SCIENCES-BASEL
(2022)
Article
Mechanics
Sebastian Dehe, Imke-Sophie Rehm, Steffen Hardt
Summary: A two-dimensional dispersion model for a dissolved species in non-uniform flow fields inside a Hele-Shaw cell is derived, incorporating an effective dispersion tensor field and advection-correction terms. The model is validated by comparing results with three-dimensional Lagrangian particle tracing simulations, showing good agreement for various test cases.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Alexander Blass, Roberto Verzicco, Detlef Lohse, Richard J. A. M. Stevens, Dominik Krug
Summary: In this study, large-scale circulation of turbulent Rayleigh-Benard convection was investigated in a large container with high Rayleigh number conditions. The results showed that the properties of LSC remain consistent even with varying boundaries, and the transition to the ultimate regime is predicted to occur in unconstrained geometries. Additionally, observations were in line with experimental data from Gottingen.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Geosciences, Multidisciplinary
Marc A. Hesse, Jacob S. Jordan, Steven D. Vance, Apurva Oza
Summary: Researchers have found that Jupiter's moon Europa has an ocean beneath its ice shell, and the habitability of this ocean depends on the availability of redox gradients. They propose that oxidants are transported through the ice shell by the drainage of near-surface brines, delivering 85% of the surface oxidants to the ocean.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Mechanics
Baole Wen, David Goluskin, Charles R. Doering
Summary: The central open question in Rayleigh-Benard convection is how vertical heat flux depends on the imposed temperature gradient in the strongly nonlinear regime. Different theories predict different relationships between Nu and Ra, and it remains uncertain which scaling theory accurately describes the relationship between the two in the infinite Ra limit.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Environmental Sciences
G. D. Beskardes, C. J. Weiss, K. L. Kuhlman, K. W. Chang
Summary: In this study, the hierarchical finite element method (Hi-FEM) is used to simulate fluid flow and heat conduction in complex geological environments. The method incorporates hierarchical basis functions and the Yeh's Galerkin model to accurately model fractured porous media, demonstrating its reliability in large-scale simulations with complex fracture networks.
WATER RESOURCES RESEARCH
(2022)
Article
Multidisciplinary Sciences
Kyung Won Chang, Hongkyu Yoon
Summary: Migration of seismic events to deeper depths along basement faults over time has been observed in the wastewater injection sites, which can be correlated spatially and temporally to the propagation or retardation of pressure fronts and corresponding poroelastic response to given operation history.
SCIENTIFIC REPORTS
(2022)
Article
Geosciences, Multidisciplinary
Evan Carnahan, Steven D. Vance, Marc A. Hesse, Baptiste Journaux, Christophe Sotin
Summary: The habitability of oceans in icy worlds depends on the transport of material and heat through their outer ice shells. The dynamics of clathrate-ice shells are essential to the thermal evolution and habitability of ocean worlds. Previous studies have not addressed the dynamics that determine the location of clathrates within the ice shell. This study shows that clathrates accumulating at the base of the ice shell are entrained throughout the shell, which limits avenues for material transport into sub-ice oceans.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Jialong Ren, Marc A. Hesse, Michael P. Lucas, Nicholas Dygert
Summary: Recent observations indicate that there is rapid cooling at high temperatures in ordinary chondrite and primitive achondrite meteorite groups, suggesting fragmentation of their parent bodies near peak temperatures. Analyzing the conductive cooling of collisional fragments, we find that the actively cooling part of a fragment experiences similar cooling rates over a wide range of temperatures. This characteristic cooling rate decreases inversely with time, and larger fragments have longer cooling times. Applying this model to the cooling rates in H chondrites, we estimate cooling times of at least 10 to 10,000 years in fragments with radii of at least 102 to 103 meters.
Article
Multidisciplinary Sciences
Baole Wen, Zijing Ding, Gregory P. Chini, Rich R. Kerswell
Summary: This article discusses the bounds of heat transport in Rayleigh-Benard convection, with upper estimate following a 5/12 scaling and lower estimate capturing a 1/3 scaling successfully.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Computer Science, Software Engineering
Javier E. Santos, Alex Gigliotti, Abhishek Bihani, Christopher Landry, Marc A. Hesse, Michael J. Pyrcz, Masa Prodanovic
Summary: MPLBM-UT is a lattice-Boltzmann library specifically designed for single- and two-phase flow simulations in porous media. It provides a comprehensive set of tools and interfaces that allow users to perform simulations and visualize results with ease.
Article
Environmental Sciences
Mohammad Afzal Shadab, Marc Andre Hesse
Summary: Understanding the controls on precipitation infiltration into soil and accurately representing it in heterogeneous media is a challenging problem in hydrology. This study investigates how the development of a saturated region in soil, caused by a downward decrease in porosity and/or hydraulic conductivity, reduces gravity-driven infiltration. The formation of a saturated region obstructs flow and leads to a rising perched water table, resulting in ponding even when rainfall intensity is lower than the surface infiltration capacity. By developing an extended kinematic wave analysis without considering capillary forces, the researchers provide a general framework to solve gravity-dominated infiltration problems for various types of downward decrease in porosity and/or conductivity. The results show excellent agreement between the developed analytic solutions and numerical solutions, as well as experimental data, supporting the effectiveness of the framework.
WATER RESOURCES RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Evan Carnahan, Steven D. Vance, Ronadh Cox, Marc A. Hesse
Summary: Impacts on icy worlds have significant effects on their ice shells, generating near-surface melt chambers and thermal perturbations that soften the ice. After impact, dense melt founders before refreezing, with over 40% of the melt draining into the underlying ocean if the transient cavity depth exceeds half the ice shell thickness. This process occurs for various ice shell thicknesses and viscosities, impacting cryovolcanism, modifying crater morphology, creating porous columns for surface-to-ocean exchange, and potentially supplying oxidants for habitability in subsurface oceans.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Michael P. Lucas, Nicholas Dygert, Jialong Ren, Marc A. Hesse, Nathaniel R. Miller, Harry Y. McSween
Summary: Primitive achondrites of the acapulcoite-lodranite clan (ALC) are residues of partial melting that resulted from burial depth variation within a primordial parent body. The ALPB experienced partial differentiation disrupted by rapid cooling, and evidence suggests melt infiltration and reaction within its layers. Thermal modeling suggests ALC samples originated from rapidly cooling collisional fragments that later reaccreted to form a slower cooling asteroid.
METEORITICS & PLANETARY SCIENCE
(2022)
Article
Geochemistry & Geophysics
Kyung Won Chang, Hongkyu Yoon
Summary: Induced seismicity is a risk associated with geologic carbon storage, often due to undetected faults. Existing modeling methods simplify or ignore important geological features and multiphysics coupled mechanisms, limiting accurate predictions of seismic hazard caused by CO2 storage. This study presents a rigorous modeling scheme that considers optimal geological and operational parameters for safe GCS, providing insights for seismic monitoring and mitigation strategies.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Nuclear Science & Technology
Bert J. Debusschere, D. Thomas Seidl, Timothy M. Berg, Kyung Won Chang, Rosemary C. Leone, Laura P. Swiler, Paul E. Mariner
Summary: Currently, simulations of spent nuclear fuel repositories do not include detailed fuel matrix degradation (FMD) process models due to their high computational cost. This study uses machine learning to develop surrogate models that approximate the FMD process model while being computationally faster to evaluate. These surrogate models, using certain inputs such as fuel cask temperature and environmental concentrations, show good agreement with the FMD process model predictions. Incorporating these surrogate models captures local and temporal environmental effects on fuel degradation rates while maintaining computational efficiency.
NUCLEAR TECHNOLOGY
(2023)
Article
Geochemistry & Geophysics
Molly S. Zebker, Jingyi Chen, Marc A. Hesse
Summary: This study presents a method to characterize both surface deformation and tropospheric noise from interferogram subsets. By choosing different subsets of interferograms that use a common-reference SAR scene, tropospheric noise and deformation signals can be quantified. The results show that there is no detectable deformation signal in Oman, while the observed interference phase in Hawaii is mostly associated with tropospheric noise.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Astronomy & Astrophysics
Angela G. G. Marusiak, Steven Vance, Mark P. P. Panning, Andrea S. S. Bryant, Marc A. A. Hesse, Evan Carnahan, Baptiste Journaux
Summary: This study investigates the impact of methane clathrates on the thermal and seismic structure of Titan. Through seismic instrumentation, the researchers explore the differences in thermal and seismic profiles between a pure water ice shell and an ice shell with a clathrate lid. The study finds that the clathrate lid reduces the thickness of the conductive lid and alters the thermal profile, resulting in lower seismic velocities and changes in seismic attenuation of the ice shell. The Dragonfly mission or future seismic investigations could provide evidence for the presence or absence of a clathrate lid by constraining the thermal and seismic profile of Titan's ice shell.
PLANETARY SCIENCE JOURNAL
(2022)