Article
Engineering, Mechanical
Jelena Stanojkovic, Miroslav Radovanovic
Summary: This paper measures and analyzes the performances, including cutting force, moment, and surface roughness, of end milling aluminum 6082-T6 with a solid carbide end mill. The study examines different values of cutting parameters, such as number of revolutions, feed rate, and depth of cut, to determine their influence on the performances and modeling of the milling process. The cutting force and moment are measured using a Kistler piezoelectric dynamometer, and the surface roughness is measured using a Mahr profilometer. The results are analyzed using the Minitab 17 software package.
FACTA UNIVERSITATIS-SERIES MECHANICAL ENGINEERING
(2022)
Article
Engineering, Chemical
A. Tiwari, B. N. J. Persson
Summary: This study examines the contact pressure of a cylinder in contact with an elastic half space with random surface roughness, finding that the pressure behavior varies with the dimensionless parameter alpha. The contact pressure is Hertzian-like for low alpha values and Gaussian-like for high alpha values, providing insight into the interaction between the cylinder and the rough surface.
Article
Engineering, Mechanical
Cagin Bolat, Berkay Ergene, Ucan Karakilinc, Ali Goksenli
Summary: In this study, machining properties of pumice reinforced AA7075 syntactic foams were investigated through facing turning. The results indicated that machining forces were influenced by operation parameters differently, with the lowest surface roughness observed at specific cutting speed and feed rate. Additionally, the shape of metal chips changed with increasing cutting speed levels, while pumice particles exhibited breakaway tendency with increased feed rates.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Birute Serapiniene, Laima Gudaviciute, Skirmante Tutliene, Asta Griguceviciene, Algirdas Selskis, Jurga Juodkazyte, Rimantas Ramanauskas
Summary: Porous 3D Cu layers were electrodeposited and different electrochemically active surface area determination methods were evaluated. The results showed that double-layer capacitance measurements yield higher values compared to underpotential deposition technique for Cu 3D nanostructures.
Article
Computer Science, Interdisciplinary Applications
Sadegh Nadimi, Vasileios Angelidakis, Masahide Otsubo, Ali Ghanbarzadeh
Summary: This paper presents a systematic study on the influence of fractal rough surfaces on contact area, aiming to advance the contact constitutive laws used in the Discrete Element Method. The mechanical behavior of computer-generated surface roughness is investigated using an in-house Boundary Element code. Various parameters are controlled to generate surfaces with specific roughness properties, and their effects on contact area are analyzed. Analytical solutions proposed in tribology are applied to predict the real contact area, and a parameter based on certain roughness properties is suggested for improved prediction. Simulation results of natural sand surfaces show similar trends with the computer-generated surfaces, but with more complexity.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Engineering, Mechanical
Pawel Maciolka, Jerzy Jedrzejewski, Wojciech Kwasny
Summary: The reliability of contact coupling simulation results was evaluated by simulating deformations using FEM and non-contact rough surface scanning. Using the experimental computational method, the difference between the contact characteristic simulation results and experimental results was determined.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Aditya Prakash, Tawqeer Nasir Tak, Namit N. Pai, Harita Seekala, S. V. S. Narayana Murty, P. S. Phani, Sivasambu Mahesh, P. J. Guruprasad, Indradev Samajdar
Summary: Macroscopic shear bands (MSB) may form during hot working of metallic materials. The microstructural transitions between the onset of flow instability and MSB inception are not fully understood. In this study, aluminum alloy specimens were tested at different temperatures and it was found that MSB only appeared at a certain level of deformation. The formation of MSB was explained by the development of clusters of severely deforming grains and the differential dynamic recovery between hard- and soft-oriented grains.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Mechanical
Xin Zhang, Lei Zhang, Zhi Yang, Xiu-chong Zhu, Yong He, Xiao Kang
Summary: The aim of this study is to investigate the evolution of the running-in process and analyze the running-in period. By establishing the relationship between contact area, plastic index, and surface roughness, and using the dimensionless real contact area as a parameter, the evolution of the running-in period of the AgCu-MoS2/AgCu10 friction pair is comprehensively analyzed.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
R. L. Jackson, T. D. B. Jacobs
Summary: The true contact area between two surfaces is only a small fraction of the apparent macroscopic contact area. This study investigates the influence of roughness at different size scales on the true contact area using a multiscale framework and a statistical roughness model. The results show that even the smallest scales can have a significant influence on the contact area, and scale-dependent strength can improve the accuracy of rough-surface contact modeling.
MECHANICS OF MATERIALS
(2023)
Article
Chemistry, Physical
Charchit Kumar, Jack Perris, Satyaranjan Bairagi, Guanbo Min, Yang Xu, Nikolaj Gadegaard, Daniel M. Mulvihill
Summary: The effect of random multiscale surface roughness on the performance of Triboelectric Nanogenerators (TENGs) was studied using a novel in-situ optical technique. It was found that the output of TENGs is highly sensitive to surface roughness, and increasing roughness leads to decreased electrical output and contact area. This study provides valuable insights for the future design of TENGs.
Article
Mathematics, Interdisciplinary Applications
Robert L. Jackson, Yang Xu, Swarna Saha, Kyle D. Schulze
Summary: This study uses the boundary element method to predict the real contact area of perfectly elastic rough surfaces, aiming to confirm the linear relationship between contact area, root-mean-square slope, and applied load predicted by fractal diffusion-based rough surface contact theory. However, experimental results reveal a complex response that deviates from the expected behavior. Further evaluation of the variation in root-mean-square slope and system spectrum related to contact features is needed to understand why this discrepancy occurs in some types of surfaces and not others.
FRACTAL AND FRACTIONAL
(2021)
Article
Automation & Control Systems
Zengfeng Duan, Ling Chen, Binbin Li
Summary: This study confirms the improvement of the cutting performance of tools with micro-textures and identifies that sinusoidal micro-textured tools exhibit the best cutting performance.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Mechanics
Qingchen Liang, Peng Liang, Feng Guo, Xiaohan Zhang, Lei Jin, Fulin Jiang, Shuyi Li
Summary: This research incorporates a mixed lubrication model and a volume-of-fluid model to study the diffusion behavior of a small amount of lubricating oil in water-lubricated bearings. The results show the existence of a backflow effect in the bearings, and increasing the shaft speed has a positive effect on oil diffusion and fluid load capacity.
Article
Optics
Sattar Ullah, Xiaoqiang Li, Guiqiang Guo, Antonio Riveiro Rodriguez, Dongsheng Li, Jianning Du, Li Cui, Lina Wei, Xiaochun Liu
Summary: Aluminum alloys pose challenges to laser cutting due to their high thermal conductivity and reflectivity. The effect of processing parameters on the mechanical performance of AA2B06-T4 alloy sheets was investigated and the impact on mechanical properties was explained in terms of the microfeatures produced in the cutting edge. The results demonstrate the capabilities of fiber laser cutting for aluminum alloys as a processing technique suitable for aeronautic applications.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Thermodynamics
Tian Xiao, Junfei Guo, Gang Liu, Xiaohu Yang, Tian Jian Lu
Summary: The paper develops a fractal model for estimating flow permeability of open-cell foam with rough surfaces, using fractal theory to characterize the randomness of pore distribution and micro roughness on metallic ligaments. The model is verified through comparison to experimental data and further explains the influence of micro-rods on permeability.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
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)