Article
Environmental Sciences
Carine G. van der Boog, Henk A. Dijkstra, Julie D. Pietrzak, Caroline A. Katsman
Summary: An analysis of in-situ ocean observations revealed the occurrence of double-diffusive thermohaline staircases in specific regions of the global ocean. The combined contribution of double-diffusive fluxes to the global ocean's mechanical energy budget is small, but its regional impact, for example near Australia, could be important.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)
Article
Engineering, Marine
Zhiguo He, Wenlin Hu, Li Li, Thomas Pahtz, Jianlong Li
Summary: Understanding the hydro-thermohaline environment at the Qiongdongnan continental slope of the northern South China Sea is crucial for meteorology and coastal ecosystems. The study uses a validated numerical model to analyze the spatial-temporal behavior of hydro-thermohaline structures and transport fluxes over a tidal period, revealing a two-layer flow structure with directional changes. Different dynamic factors control heat and salt transport over a tidal period, with gravitational convention and mean flow dominating heat transport and mean flow dominating salt transport.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
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
Oceanography
A. Anutaliya, U. Send, J. L. McClean, J. Sprintall, M. Lankhorst, C. M. Lee, L. Rainville, W. N. C. Priyadarshani, S. U. P. Jinadasa
Summary: Boundary currents along the eastern and southern coasts of Sri Lanka play a crucial role in salt exchange between the Bay of Bengal and the Arabian Sea, influenced by monsoonal wind reversal and large-scale climate modes.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Mechanics
Qiang Du, Yaguang Xie, Zhicheng Wang, Xiaomo Jiang, Lei Xie
Summary: In this paper, an entropy viscosity subgrid model based on the LES method is proposed to solve complex flow with heat transfer in a rotating frame at high Reynolds numbers. By performing 12 simulations, the sensitivity of the simulation results to mesh resolution and the free parameters of entropy viscosity are systematically studied, and the proper range for the parameters is determined. The entropy viscosity-based LES uses a coarser mesh resolution compared to direct numerical simulation, making it feasible to apply LES to flow at practical Reynolds numbers in an aircraft engine.
Article
Thermodynamics
X. -Y Leng, J. -Q Zhong
Summary: This study numerically investigates the effects of geometry factors, such as aspect ratio Gamma and radius ratio eta, on axial heat transport (Nu) and radial angular momentum transport (N-omega) in turbulent Taylor-Couette flows. The results show that both Nu and N-omega display a pronounced aspect-ratio dependence, with different magnitudes depending on the Reynolds number (Re).
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Chemical
Bin Wu, Naixin Wang, Yue Shen, Cheng-Gang Jin, Quan-Fu An
Summary: In this study, inorganic salts were used to regulate interfacial polymerization reactions and break the electrostatic interaction between zwitterions, promoting cross-linking of zwitterionic polyamide networks and forming an intact and ultrathin separation layer. The obtained ZNFMs showed high permeance and rejections for antibiotic/monovalent salt separation, as well as exceptional anti-fouling property.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
Peter M. F. Sheehan, Gillian M. Damerell, Philip J. Leadbitter, Karen J. Heywood, Rob A. Hall
Summary: Ocean gliders enable high-resolution microstructure observations for calculating turbulent kinetic energy dissipation rate, epsilon, on longer timescales than traditional ship-based platforms. In this study, we report the first detailed estimates of epsilon using the Batchelor spectrum and Thorpe scale methods on observations collected by a Seaglider. The two methods show good agreement, with the Thorpe scale method yielding slightly larger values of epsilon.
Article
Mechanics
J. G. Chen, R. A. Antonia, Y. Zhou
Summary: An equation that quantifies the relationship between the principal derivative of the Reynolds shear stress and large-scale vorticity fluxes is developed and validated using experimental data. The study reveals that when large-scale vortices dominate, the Reynolds shear stress associated with coherent motion can be approximated by the conventional Reynolds shear stress. The latter is mainly determined by the imbalance between the dynamic pressure arising from streamwise non-homogeneity induced by large-scale vortical structures and the lateral coherent vorticity flux.
Article
Engineering, Civil
Xudong Zhang, Changjian Shu, Manabu Fujii, Yajun Wu, Dean Sun, Peng Ye, Yiding Bao
Summary: This study compares numerical simulations with indoor evaporation tests to investigate water and salt transport in saline soils. The results show that soil salinity greatly impacts temperature changes and water retention. The modeled results agree with experimental data, indicating the effectiveness of the model in simulating water-heat-salt transport in different saline sites. This model is crucial for improving saline soils and preventing further soil salinization.
JOURNAL OF HYDROLOGY
(2023)
Article
Geochemistry & Geophysics
Runze Tian, Yu Zhang, Anhua Xu, Xuemei Li, Yunlong Hou, Bowen Tai
Summary: Through experiments and mathematical modeling, it was found that highly chlorinated saline soils exhibit a tendency for water and salt to migrate towards the cold end during the cooling process. Different chlorine content soils showed variations in water and salt content, with phase change temperature set in numerical simulations to match experimental results.
Article
Physics, Multidisciplinary
M. H. Hamede, S. Merbold, C. Egbers
Summary: The present study experimentally investigates the transition from the classical to ultimate regime in a wide-gap Taylor-Couette flow. The transition occurs at shear Reynolds numbers of 2.5x10(4) <= Re-s <= 3.7x10(4). Angular momentum transport is measured by torque sensors, and radial and azimuthal velocities are measured using Particle-Image-Velocimetry (PIV). The angular momentum flux shows a scaling behavior similar to Re-s(0.76) for Re-s >= 2.5x10(4), and spectral analysis reveals the presence of highly energetic small-scale and large-scale patterns in the classical regime and only large-scale patterns in the ultimate regime.
Article
Physics, Multidisciplinary
Simon Grall, Shuo Li, Laurent Jalabert, Soo Hyeon Kim, Arnaud Chovin, Christophe Demaille, Nicolas Clement
Summary: This article introduces a formalism to describe the electrochemical shot noise of a redox monolayer, which has been experimentally confirmed at room temperature in a liquid environment. The proposed method, performed at equilibrium, eliminates parasitic capacitance and increases sensitivity, allowing for quantitative information about electron coupling, dispersion, and the number of molecules. Unlike solid-state physics, the homogeneity in energy levels and transfer rates in the monolayer results in a Lorentzian spectrum. This study opens up possibilities for quantum transport research in liquid environments at room temperature and highly sensitive measurements for bioelectrochemical sensors.
PHYSICAL REVIEW LETTERS
(2023)
Article
Agronomy
Lucia Curto, Maria Gassmann, Mauro Covi, Natalia E. Tonti
Summary: In this study, turbulence structures above maize and soybean crops under neutral and unstable conditions were investigated using quadrant analysis. The results revealed strong unstable situations in maize crops, while soybean crops exhibited near-neutral conditions. Sensible heat and momentum fluxes were driven by the same motions, with ejections being more important in soybean crops.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Physics, Fluids & Plasmas
B. Ph van Milligen, I Voldiner, B. A. Carreras, L. Garcia, M. A. Ochando
Summary: In this study, we measured turbulent quantities inside the plasma edge in the TJ-II stellarator using a Langmuir probe during rotational transform scans. We found that the poloidal plasma velocity and radial electric field have a radial structure that relates to the rotational transform profile and lowest order rational surfaces. The particle flux and flow shear suppression term also exhibit a radial pattern, but their relation to the low-order rational surfaces is less clear. The results suggest the presence of an unknown term, the instability growth rate, in the turbulence evolution equation.