Article
Environmental Sciences
Matthias Jakob, Sarah Davidson, Gemma Bullard, Matthias Busslinger, Beatrice Collier-Pandya, Patrick Grover, Carie-Ann Lau
Summary: This paper discusses the occurrence and categorization of debris floods in steep mountain channels and small gravel bed rivers. Debris floods are classified into three categories based on their triggers, and their hazards involve inundation, scour, sediment transport, and bank erosion. The study introduces an approach for hazard quantification and mapping, aiming to homogenize debris-flood hazard assessments and mapping methodologies.
WATER RESOURCES RESEARCH
(2022)
Article
Water Resources
Costanza Di Stefano, Alessio Nicosia, Vincenzo Palmeri, Vincenzo Pampalone, Vito Ferro
Summary: The research indicates that soil texture type affects the velocity profile parameter and flow resistance in rill flow, and an 18% slope can distinguish different flow situations. The detachability and transportability of soil particles affect the estimation of the Darcy-Weisbach friction factor.
HYDROLOGICAL PROCESSES
(2021)
Article
Thermodynamics
C-H Kim, N-H Kim
Summary: This study investigated two-phase flow distribution in a parallel flow condenser using R-134a flow distribution tests. The results showed relatively uniform flow distribution within the channels, with variations at the top and bottom channels. Thermal degradation due to flow mal-distribution was found to be insignificant.
APPLIED THERMAL ENGINEERING
(2021)
Article
Water Resources
Songyan Yu, Ryan M. Burrows, Margaret Shanafield, Mark J. Kennard
Summary: This study found that the water level in non-perennial streams recedes at a constant rate after streamflow ceases, which is often higher than that during low-flow periods. However, water-level recession rates vary significantly between different cease-to-flow periods and streams. Further research is needed to understand the factors influencing water-level recession rates for ungauged streams and identifying persistent aquatic refuges across river networks.
ADVANCES IN WATER RESOURCES
(2022)
Article
Acoustics
Shail A. Shah, Hans Boden, Susann Boij
Summary: Perforated plates are widely used in passive noise-control systems and this study continues to provide experimental results using different test setups. The passive acoustic response of a perforated plate is studied under excitation from three directions in the presence of grazing flow and high-amplitude acoustic excitation. The three-port technique used in this study allows for direct impedance determination without traditional boundary conditions.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Geosciences, Multidisciplinary
Francesco Giuseppe Carollo, Vito Ferro
Summary: This study explores the relationship between the gamma coefficient of power velocity distribution, channel slope, and Froude number in open channel flows. Experimental measurements in laboratory flumes were used to calibrate this relationship and study the impact of roughness element concentration on flow resistance. The findings were also verified through measurements in gravel bed rivers, demonstrating accurate estimation of friction factor using the proposed flow resistance equation and gamma function estimation.
Article
Mechanics
O. O. Ivanov, D. A. Ashurov, L. R. Gareev, V. V. Vedeneev
Summary: This study identifies the non-modal "lift-up" growth mechanism through experiments and confirms that the development of disturbances qualitatively corresponds to the theoretically calculated optimal perturbations. The features of the transition to turbulence caused by non-modal growth are discussed.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Geochemistry & Geophysics
L. Spina, A. Cannata, D. Morgavi, E. Privitera, D. Perugini
Summary: This study investigates the gliding phenomenon of acoustic and seismic tremors observed in analogue degassing experiments. It finds that the gliding episodes are mostly related to the volume variation of shallow interconnected gas pockets. The findings have implications for the churn dynamics in volcanic environments and call for further research.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Mechanics
Ould El Moctar, Udo Lantermann, Vladimir Shigunov, Thomas E. Schellin
Summary: The effects of deck container arrangement on wind-induced loads were investigated using physical model tests and numerical computations. Various turbulence models were used to predict aerodynamic loads, and the agreement between predictions and measurements was evaluated. The results showed that the container arrangement on deck significantly influenced the aerodynamic forces and moments, especially in oblique winds.
Article
Mechanics
Wangqiao Chen
Summary: This study is devoted to experimentally investigate the acoustic receptivity in the airfoil boundary layer using time-resolved particle image velocimetry method. The symmetric vortex shedding process is observed, and a hysteresis phenomenon is discovered with the increasing and decreasing wind speed. The author applies the Hilbert transform to show a space-wavenumber spectrum of wall-normal velocity fluctuations to locate resonance points, where acoustic pressure resonates with fluctuations in the boundary layer. The results demonstrate that acoustic reception can influence local velocity to increase and decrease the wavenumber before and after reaching resonance points. The trailing edge noise impacts on the airfoil boundary layer to control the system states and follows the same acoustic feedback loop as Arbey and Bataille's study.
Article
Thermodynamics
Zhen Xu, Xuanyu Zhang, Shuo Kong
Summary: The heat transfer and flow resistance characteristics of in-tube vapor condensation with high content noncondensable gas are experimentally investigated. The results show that the corrugated tube and spiral tube have higher heat transfer coefficients and pressure drops compared to the bare tube. The maximum comprehensive performance coefficients are 1.71 and 1.44 for corrugated tube and spiral tube respectively.
APPLIED THERMAL ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Peng Lin, Yan Jin, Feifang Gan, Guojun Ma, Changgui Cheng, Yang Li, Ziyu Liu, Jun Li, Jingyu Huang
Summary: In this study, the performance of turbulence inhibitors was investigated by simulating the fluid fields and stress distribution during the opening stage of the tundish. It was found that the maximum stress in the turbulence inhibitor is influenced by factors such as the depth of molten steel, eave width, and material strength.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2022)
Article
Polymer Science
Anna Dmochowska, Jorge Peixinho, Cyrille Sollogoub, Guillaume Miquelard-Garnier
Summary: This study investigates the effect of shear on the bursting of molten ultrathin polymer films embedded in an immiscible matrix. The experiment reveals that shear modifies the circularity of the formed holes and increases their growth speed. A proposed model balances capillary forces and viscous dissipation, while considering shear thinning, and captures the main features of the experimental data. This research provides insights into the instabilities occurring during processing of layered polymeric structures.
Article
Chemistry, Physical
Alexander I. Guryanov, Oleg A. Evdokimov, Vladimir A. Burtsev, Valeriy I. Koshkin, Sergey V. Veretennikov, Olga V. Komova
Summary: The bidirectional swirling flow structure in the combustion of methane and syngas provides a significant decrease in lean blow-off equivalence ratio and emissions of main pollutants. Co-combustion of syngas and methane is the most suitable fuel utilization mode, achieving similar blow-off and emission properties as pure syngas combustion with lower energy consumption.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Mechanics
G. Rousseau, C. Ancey
Summary: The study found that steep streams have different flow dynamics compared to low-gradient streams. The flow dynamics of steep streams are largely affected by turbulence damping, drag forces, and dispersion within the roughness layer. An algebraic closure equation was proposed to model the influence of dispersive shear stress in steep streams.
JOURNAL OF FLUID MECHANICS
(2022)