Article
Physics, Fluids & Plasmas
Rebecca A. McKinlay, Alexander W. Wray, Stephen K. Wilson
Summary: A combination of analytical and numerical techniques is used to provide a detailed description of the late-time draining behavior of a thin liquid film on a stationary horizontal circular cylinder. The film can be divided into draining and pendant-drop regions, connected by a narrow inner region. The draining region is characterized by thinning of the film due to gravity, while the pendant-drop region exhibits a quasistatic balance between gravity and capillarity. These two regions are connected through an inner region with a capillary-ripple structure. The dimples and ridges in the inner region have different thickness profiles and become observable as the draining progresses.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Andrew J. Mitchell, Brian R. Duffy, Stephen K. Wilson
Summary: This paper revisits the problem proposed by Newell and Viljoen, who considered the effect of airflow on the coating flow of a thin film. In contrast to their claim of conditional instability, the study shows that the film remains unconditionally stable in the presence of airflow.
Article
Engineering, Civil
Naveed Ul Hassan Bhat, Gourabananda Pahar
Summary: The present study aims to develop a robust two-dimensional framework for simulating the submarine deformation of non-cohesive granular media and its impact on water bodies. The proposed framework has been validated against various test cases and shows potential for real-time extension to field-scale problems.
JOURNAL OF HYDROLOGY
(2022)
Article
Mathematics, Applied
Jean Carlos Nakasato, Igor Pazanin
Summary: This paper investigates the flow of a non-Newtonian fluid through a thin three-dimensional domain with an oscillating boundary. By rigorously deriving three different effective models based on the period of the boundary roughness, the study reveals the roughness-induced effects on the fluid flow.
ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK
(2023)
Article
Computer Science, Interdisciplinary Applications
Mohammad Nikooei, Clarence Edward Choi
Summary: This study proposes a new approach to model the effects of deposition in flow-type landslides. By simulating the flow-normal accelerations during the deposition process, a deposition model that considers the initial aspect ratio and slope angle of the debris is developed and implemented into engineering simulations. The new model improves predictions of flow distance and duration, and overcomes limitations of traditional models. This research is important for improving the delineation of flow-type landslides in mountainous regions.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Xiaoli Su, Qiuhua Liang, Xilin Xia
Summary: A new coupled model combining discrete element method and depth-averaged model was developed to simulate flow-like landslides. Experimental and simulation results confirm the model's ability to accurately reproduce the dynamic process of real-world flow-like landslides.
ENVIRONMENTAL MODELLING & SOFTWARE
(2022)
Article
Chemistry, Physical
Surajit Dutta, Vivas Bagwe, Gorakhnath Chaurasiya, A. Thamizhavel, Rudheer Bapat, Pratap Raychaudhuri, Sangita Bose
Summary: This study presents the growth, characterization, and superconducting properties of a new amorphous superconductor, RexZr (x approaching 6), in thin films. It was found that films with thickness greater than 40 nm exhibited a superconducting transition temperature of 5.9 K, with marginal changes in superconducting properties as the film thickness decreased to 8 nm. Scanning tunneling spectroscopy and penetration depth measurements supported the evidence for a single-gap strong coupling s-wave superconductor.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Thermodynamics
S. Y. Misyura, R. I. Egorov, V. S. Morozov, A. S. Zaitsev
Summary: This study investigates the evaporative behavior of a water layer and the heat transfer under local heating. Non-stationary and non-isothermal heat exchange conditions were created using laser heating, and the thermal field on the free surface of the layer was recorded using thermal imaging technology. Changes in liquid mass due to evaporation were determined using the gravimetric method. The study estimates the key factors affecting water evaporation and compares the characteristic heat fluxes associated with evaporation, radiation, and convection.
APPLIED THERMAL ENGINEERING
(2023)
Article
Nuclear Science & Technology
Chidambaram Narayanan, Emeline Beltjens, Rita Szijarto, Dionysios Chionis, Christian Hellwig
Summary: The study presents the application of a fluid film model to analyze the interaction between vapour flow and liquid film dynamics, clarifying the basic relationship between vapour velocity, liquid film thickness, and velocity distribution along a rod. The model is applied to both simplified and real assembly geometries, showing the impact of part length rods on flow pattern and the potential for variation in wall shear to affect local heat and mass-transfer characteristics. The modelling palette for the depth-averaged film model contains features that extend the validity of the study, but future work could explore additional factors like droplets in the vapour core and the influence of spacers.
NUCLEAR ENGINEERING AND DESIGN
(2022)
Article
Thermodynamics
Meng Zhu, Lei Chen, Sheng Su, Song Hu, Kai Xu, Peiwen Yan, Haoran Qing, Lingang Zhou, Aishu Li, Jing Zhou, Yi Wang, Jun Xiang
Summary: This study experimentally and numerically investigated the turbulent flow of supercritical CO2 in a vertical upward tube. The results showed that the effects of mass flux and pressure on friction pressure drop under non-isothermal conditions are similar to those under isothermal conditions. Moreover, under high heat flux condition, both the viscous shear stress and Reynolds shear stress decrease, with the Reynolds shear stress being the key factor affecting the friction pressure drop.
APPLIED THERMAL ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Qiling Wang, Peng Xiao, Wei Zhou, Yun Liang, Guangqiang Yin, Qiu Yang, Shiao-Wei Kuo, Tao Chen
Summary: This article describes an ultrathin, elastic, and adaptive underwater sensor based on graphene film, which can sense water depth and environmental stimuli, and has the potential to play an important role in underwater monitoring, communication, and risk avoidance.
NANO-MICRO LETTERS
(2022)
Article
Engineering, Geological
Wen-Jie Shiu, Ching-Fang Lee, Chia-Chi Chiu, Meng-Chia Weng, Che-Ming Yang, Wei-An Chao, Chun-Yuan Liu, Cheng-Han Lin, Wei-Kai Huang
Summary: This study proposed a hybrid model to simulate the development of debris flow and bridge collapse event in the Yusui Stream. The simulation results indicated reasonable simulations of the formation of natural dam, erosion at the flow region, failure process of the Minbaklu Bridge, and deposition of alluvial fan.
Article
Engineering, Electrical & Electronic
Dawei Chen, Can Wan, Yonghua Song, Chuangxin Guo, Mohammad Shahidehpour
Summary: This paper proposes a novel non-isothermal optimal power and gas flow (OPGF) model that avoids the isothermal assumptions in traditional natural gas network models and significantly improves accuracy. The model introduces the gas temperature change into the coordinated operation of integrated electricity and natural gas systems by incorporating the finite difference method and laws of thermodynamics. Numerical experiments validate the effectiveness of the proposed OPGF model and solution methodology.
IEEE TRANSACTIONS ON POWER SYSTEMS
(2021)
Article
Computer Science, Interdisciplinary Applications
Xiaoli Su, Xilin Xia, Qiuhua Liang, Jingming Hou
Summary: This paper develops a novel landslide model by coupling a DEM model with a DAM for landslide simulation. The new coupled model is able to reproduce the dynamic process of flow-like landslides.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Thermodynamics
Manish K. Khandelwal, Nidhi Singh
Summary: This paper reports the linear stability analysis of a viscous flow of water with temperature-dependent viscosity between two differentially heated concentric cylinders. The results show that the velocity profiles possess a point of inflection when the temperature difference between the cylinders exceeds 80.0 K. The disturbance growth rate increases with the curvature parameter and temperature differences, while the critical Reynolds number decreases.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)