Article
Thermodynamics
Riadh Ouzani, Sofiane Khelladi
Summary: Numerical simulations were used in this study to investigate the influence of density inversion on the dynamics and mixing process of finger structures. A numerical methodology based on the finite volume method and high accuracy schemes was utilized to solve the two-dimensional Navier-Stokes equations for high buoyancy ratio and moderate thermal Rayleigh number. The density was assumed to depend quadratically on temperature and linearly on salinity. The results showed that density inversion significantly affected the flow pattern and asymmetric motions were observed as the nonlinear parameter increased. In the nonlinear cases, the sinking fingers rapidly evolved and increased due to enhanced buoyancy force. The density inversion played a significant role in the mixing process, with an increase in the nonlinear parameter enhancing mixing dynamics in the lower layer.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Physics, Fluids & Plasmas
Junyi Li, Yantao Yang
Summary: This study investigates the influence of background shear on fingering double diffusive convection. Numerical simulations reveal that a weak shear enhances the salinity flux, but this enhancement effect decreases with higher Rayleigh numbers. Stronger shear leads to a shift from salt fingers to salt sheets as dominant structures, with an increase in coherence length scale and decrease in salinity and heat fluxes.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Mechanics
Jonathan S. Cheng, Ibrahim Mohammad, Bitong Wang, Declan F. Keogh, Jarod M. Forer, Douglas H. Kelley
Summary: The study reveals robust scaling properties of primary flow modes in a liquid gallium convection system, with sensitivity to both Reynolds number and aspect ratio. Temperature and velocity spectra consistently exhibit peaks at specific frequencies, with the presence of a secondary peak highly dependent on aspect ratio.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Geochemistry & Geophysics
David Fukuyama, Hugh C. Daigle, Michael A. Nole, Wen Song
Summary: Short-range diffusion and long-range advection are the main mechanisms for transporting methane. This study introduces a new mechanism, density-driven convection, which is driven by hydrate formation and salt exclusion in the pore water. The study demonstrates the rapid transport of aqueous methane throughout the sand layer with convection compared with diffusion.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Thermodynamics
Deepak Kumar Singh, O. P. Singh
Summary: In this study, we investigate the dynamics of the evolution of the thermohaline layer in a double-diffusive salt finger system. We use a high-resolution numerical model to simulate a two-layer finger system and explore the critical power-law time scales for various parameters. Our findings reveal a relationship between the power-law time scale of the density inversion ratio and the ratio Phi, approximately equal to 1.618.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Mechanics
Kevin Zhong, Nicholas Hutchins, Daniel Chung
Summary: In the fully rough regime, proposed models predict a scaling for roughness heat-transfer coefficient. Direct numerical simulations of forced convection over a three-dimensional sinusoidal surface were conducted to clarify this ambiguity. The overall picture of fully rough heat transfer is not encapsulated by one singular mechanism or phenomenology, but rather an ensemble of different behaviors locally.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Fluids & Plasmas
Yuchen Ma, W. R. Peltier
Summary: The study extends the gamma instability theory to salt-fingering systems with varying vertical gradients, explaining the faster formation and merging of salt-fingering staircases in low-gradient regions. It demonstrates that the most quickly growing mode of instability is unaltered by the inhomogeneity of the background stratification in most cases.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Thermodynamics
Yuhui Cao, Jia-Wei Tong
Summary: Three-dimensional simulations are conducted to investigate the flow regimes and heat transfer behaviors in the rotating thermal flow of cold water near its density inversion point. The study identifies eleven flow regimes and reveals the mechanisms of heat transfer enhancement and non-monotonic variation. The results provide insights into the spatio-temporal features and relative strength of flow between the inner and outer layers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Construction & Building Technology
Waleed Sulaiman Mustafa, Janos Szendefy, Balazs Nagy
Summary: The use of glass waste in construction industry has high potential for increased recycling. Foam glass aggregate (FGA) is a recycled glass waste with good insulation properties. Investigating the impact of different compaction ratios, temperature, and relative humidity on the thermal performance of FGA is crucial. The study found that compaction ratios influenced the material's properties, including density, strain, and thermal conductivity.
Article
Chemistry, Physical
Huichao Liu, Hua Song, Liping Feng, Wenjing Hou, Yunzhen Chang, Ying Zhang, Yun Zhao, Sheng Zhu, Gaoyi Han
Summary: This study develops a simple molten salt-assisted method for constructing nitrogen-doped mesoporous carbon (NMPC) with high specific surface area and mesopore-dominant porous structure, improving the capacitive performance of the electrode. The optimized NMPC electrode exhibits high specific capacitance and superior rate capability in an aqueous alkaline electrolyte. Furthermore, the symmetric supercapacitor assembled by NMPC achieves a high energy density in a TEABF(4)/acetonitrile electrolyte.
APPLIED SURFACE SCIENCE
(2022)
Article
Mathematics, Applied
M. Najafian, M. S. Mortazavi
Summary: This paper investigates the evaporation of droplets and proposes a two-step algorithm to solve problems with high-density ratios. The results demonstrate the accuracy and feasibility of this modified method.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Yu-Long Hai, Hui-Li Tian, Meng-Jing Jiang, Han-Bin Ding, Yu-Jie Feng, Guo-Hua Zhong, Chun-Lei Yang, Xiao-Jia Chen, Hai-Qing Lin
Summary: This article investigates the superconducting properties of metal-free hydrides H6SX (X = Cl and Br) from a theoretical perspective. The results show that H6SCl and H6SBr are potential superconductors with high transition temperatures.
Article
Chemistry, Physical
Francesca Fasulo, GiovanniMaria Piccini, Ana B. Munoz-Garcia, Michele Pavone, Michele Parrinello
Summary: Anatase TiO2 is a functional material widely used in various technological devices. This study investigates the interaction between water and the (101) anatase surface using first-principles simulations. The presence of hydroxyl groups on the surface at low water coverage is observed. The results show that water can adsorb barrierlessly and dissociate to form partially hydroxylated surface at room temperature, highlighting the importance of dynamic modeling for surface-water interactions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Energy & Fuels
John Severino, Rhys Jacob, Martin Belusko, Ming Liu, Frank Bruno
Summary: The pycnometric method was used to determine the liquid density of carbonate and/or chloride salts at high temperatures, with quick and repeatable measurements. Validation was done using sodium chloride as a reference material, showing a small error of +/- 0.6%. The study found a linear decrease in liquid density from the melting point in all cases.
JOURNAL OF ENERGY STORAGE
(2021)
Article
Mathematics
Cole Hugelmeyer
Summary: The passage explores mathematical problems related to Lebesgue measure and projective planes, ultimately arriving at a conclusion about a lower bound on probabilities.
ANNALS OF MATHEMATICS
(2021)