Article
Thermodynamics
Yadong Chen, Yuxuan Yang, Xiaoxiao Shi, Wenrui Zhang, Liansheng Liu, Xuanchen Liu
Summary: In this paper, the dynamic evolution of a single drop impacting a horizontal hydrophilic wire is explored through experiments and numerical simulation methods. The movement behavior law of the drop impacting the curved surface is analyzed by combining the phenomena of spreading, retracting, and breaking. Moreover, the effects of eccentricity, Weber number, and wall wettability on drop impact spreading dynamics are studied.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Sanyam Sharma, Chimata M. Krishna
Summary: This study analyzed the stability of non-circular offset bearings using the finite element method, with selected input parameters such as eccentricity factor and aspect ratio. Output parameters including load, critical mass, whirl frequency ratio, and threshold speed were computed and plotted, showing that micropolar lubricated circular offset bearings exhibit high stability at higher eccentricity factors and aspect ratios.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Aerospace
Dan Sun, Shuang Wang, Huan Zhao, Min Zhou, Ran Zhang, Shuaifang Wen
Summary: This paper studies the static and dynamic characteristics of a labyrinth seal through fluid-solid-thermal coupling analysis (FSTCA). The deformation and stress distribution of nonmetallic labyrinth seals (such as PEEK and PEEK-CA30) are analyzed to understand their impact on leakage and rotor stability compared to metallic material (AL alloy). The results show that PEEK-CA30 has lower deformations and better seal performance and rotor stability, while AL alloy is more likely to fail at higher inlet temperatures due to its properties.
JOURNAL OF AEROSPACE ENGINEERING
(2023)
Article
Chemistry, Physical
Liansheng Liu, Yuxuan Yang, Wenrui Zhang, Xuanchen Liu
Summary: In this study, the behavior characteristics of droplets impacting hydrophilic wires are investigated using experiments and numerical simulations. The effects of eccentricity, Weber number, and Reynolds number on droplet morphology evolution are analyzed under fixed size ratio conditions, and the flow characteristics of central and eccentric impact are compared. The results show that these factors significantly affect the droplet's dynamic characteristics and the stability of droplet spreading.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Acoustics
Xi Chen, Xiaohua Gan, Guangming Ren
Summary: This study simulated and analyzed the dynamic responses of an oil-lubricated rotor-bearing system under base motions, highlighting the significant influence of oil-film inertia, static eccentricity, and base motions on the transient responses and bifurcation behavior of the system. Results show that oil-film inertia can increase reaction forces under large eccentricity ratios, while medium and large static eccentricities lead to quasi-periodic motions in the journal bearings.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Geological
Chunyong Jiang, Xuanming Ding, Huaqiang Fang, Jing Lian
Summary: Research has found that coral silt, a type of coral soil with over 50% silt content, is formed during land reclamation. The cyclic dynamic shear characteristics of coral silt are important for determining the seismic safety of reef infrastructures due to the frequent action of waves, wind, earthquakes, and other dynamic loads. Symmetrical and asymmetrical cyclic simple shear tests were conducted to investigate the cyclic behavior of coral silt, with emphasis on the static-cyclic shear stress coupling. Empirical formulas were proposed to estimate the undrained peak shear strength and critical state strength in monotonic simple shear tests. The CSR threshold value, ranging from 0.05 to 0.075, controlled the final failure in both symmetrical and asymmetrical-loading cyclic simple shear tests. The cyclic shear stress had a significant influence on the cyclic deformation, cyclic pore water pressure, cyclic strength, and cyclic shear modulus of coral silt.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
S. K. Singh, A. Banerjee, R. K. Varma, S. Adhikari, S. Das
Summary: This paper presents an analytical study on computing natural frequencies and in-plane deflections caused by static forces in panel walls using various theories. The study emphasizes the unique features of the Micropolar-Cosserat theory and its comparison with finite element analysis for simulating panel behavior.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Thermodynamics
Milos Kocic, Zivojin Stamenkovic, Jelena Petrovic, Jasmina Bogdanovic-Jovanovic
Summary: The analysis of mass and heat transfer in magnetohydrodynamic (MHD) flows has various important applications in different fields. Similarly, micropolar fluid flows, which include flows of crude oil, blood, and other polymer fluids or liquid crystals, also have significant implications. This paper focuses on the stationary flow of a micropolar fluid influenced by an external magnetic field, considering the temperature difference between two plates and the non-inductive approximation. Analytical solutions are obtained for velocity, microrotation, temperature, shear stress at plates, Nusselt number, and flow rate. By analyzing the results, this study offers general conclusions about the influence of magnetic fields and physical characteristics of micropolar fluids in porous media, contributing to our understanding of these flows and their significance.
ADVANCES IN MECHANICAL ENGINEERING
(2023)
Article
Thermodynamics
Pramod Kumar Yadav, Ankit Kumar
Summary: This study investigates the entropy production of two-phase non-miscible Newtonian and micropolar fluid in a rectangular conduit, using different flow regime distribution and boundary conditions. It analyzes the impact of various parameters on fluid flow, thermal exchange, entropy production number and Bejan number, and verifies the findings with previously established results through graphical representation. The results of this analysis have applications in the petroleum industry.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Energy & Fuels
Yu-Ling He, Xiang-Ao Liu, Ming-Xing Xu, Wen Zhang, Wen-Jie Zheng, De-Rui Dai, Gui-Ji Tang, Shu-Ting Wan, David Gerada
Summary: This article comprehensively investigates the stator winding circulating current inside parallel branches of a doubly fed induction generator, focusing on different types of air-gap eccentricities. Theoretical analysis is verified through finite element analysis and experimental studies, providing a supplementary criterion for diagnosing eccentric faults in DFIGs.
Article
Mechanics
Zhenggui Li, Zhao Yuan, Xinrui Li, Menggui Wang, Guoqing Zhu
Summary: In this study, the changes in interfacial shape and width of a magnetic fluid seal were numerically simulated and experimentally verified. Results showed that the pressure resistance decreased with an increase in seal clearance, and the magnetic fluid seal interface generated a small leakage channel. Compared to a static seal, the dynamic seal exhibited a larger change in interface width.
Article
Construction & Building Technology
Tengjiao Wang, Jinyu Xu, Erlei Bai, Biao Ren, Song Lu
Summary: Concrete in buildings is susceptible to the coupling effects of high temperature and static-dynamic coupled loads in case of fire. Dynamic mechanical properties and crushing modes of concrete under static-dynamic coupled loads were analyzed through tests with different axial static pressure ratios and temperatures. It was found that axial static pressure can significantly improve dynamic strength characteristics at ASPR of 0.4, but can lead to deterioration at higher ratios, while high temperature above 400 degrees C significantly decreases dynamic strength.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Thermodynamics
Z. Hai-lun, C. Xi, Z. Ming
Summary: The study investigates the periodically time-varying dynamic characteristics of static eccentric squeeze film dampers (SFD) using two computational fluid dynamics models. Results show that oil-film damping and stiffness exhibit distinct periodically time-varying characteristics due to static eccentricity, with a shift towards the influence of static eccentricity as dynamic eccentricity increases.
JOURNAL OF APPLIED FLUID MECHANICS
(2021)
Article
Geosciences, Multidisciplinary
Zesheng Zang, Zhonghui Li, Enlai Zhao, Xiangguo Kong, Yue Niu, Shan Yin
Summary: This study investigates the relationship between the electrical and magnetic signals generated by coal fracture and its mechanical properties and fracture behavior. The results show that under the coupling of axial static load-dynamic load, noticeable electrical potential (EP) signals are stimulated in coal, and the change in EP signal correlates well with the change in mechanical behavior. The study also reveals the mechanisms by which different variables affect the EP response of coal.
NATURAL RESOURCES RESEARCH
(2023)
Article
Energy & Fuels
Jianping Yuan, Jiali Shi, Yanxia Fu, Huilong Chen, Rong Lu, Xueliang Hou
Summary: In this study, the internal flow and deformation of the impeller in a centrifugal pump were analyzed using calculations and simulations. The study found that closed impellers have the worst stability but the best hydraulic performance, while impellers with split blades have the opposite characteristics.
Article
Engineering, Mechanical
Sanyam Sharma, Chimata M. Krishna
Summary: This study analyzed the stability of non-circular offset bearings using the finite element method, with selected input parameters such as eccentricity factor and aspect ratio. Output parameters including load, critical mass, whirl frequency ratio, and threshold speed were computed and plotted, showing that micropolar lubricated circular offset bearings exhibit high stability at higher eccentricity factors and aspect ratios.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Puneet Kumar Singh, Krishna Chimata Murali
Summary: Medical robots offer great potential for improving precision in surgical procedures and detecting colon cancers. Research shows that silicone rubber is a suitable material for colonoscope, providing comfort for the patient during procedures.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Mechanical
Sanyam Sharma, Chimata Murali Krishna, Rajesh Singh
Summary: This paper evaluates the theoretical performance of elliptical dam bearing (EDB) and studies the influence of eccentricity ratio, dam parameters, and micropolarity parameters on its stability under micropolar lubrication. The results show that micropolar lubricated EDB provides better stability at smaller material length, and thus, selecting a smaller characteristic length and a larger dam width can achieve optimum performance.
INDUSTRIAL LUBRICATION AND TRIBOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Madhusudan Baghel, C. M. Krishna, S. Suresh
Summary: In this research, Al-SiC composite material was developed from rice husk using a CNC milling machine. The material's surface was characterized and its mechanical properties were studied. The results showed that the composite material has a large surface area and good fracture toughness, making it suitable for aerospace applications.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Engineering, Chemical
Madhusudan Baghel, C. M. Krishna
Summary: The objectives of this work are to investigate the microstructural characterization of multi-walled carbon nanotubes (MWCNTs) produced by a chemical vapor deposition method and to prepare Al6082/MWCNT nanocomposites by a stir casting method. The study found that the dispersion of MWCNTs can be improved by coating them with aluminum powder through ball milling and using ultrasonic mixing. The addition of MWCNTs in varying weight percentages during the stirring process yielded a uniform distribution up to 0.9 wt. %, beyond which agglomeration occurred. The purified MWCNTs were found to be free of nickel and other impurities.
PARTICULATE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Madhusudan Baghel, C. M. Krishna
Summary: A modified stir casting method was used to fabricate Al6082 composites reinforced with multiwalled carbon nanotubes (MWCNTs), and a heat treatment process was applied to enhance their mechanical strength. The addition of MWCNTs significantly improved the mechanical properties of the nanocomposites. The fractography analysis revealed different fracture modes for composites with different MWCNTs content.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Madhusudan Baghel, Chimata Murali Krishna
Summary: In this study, MWCNTs/Al6082 composites were prepared by stir casting, and their tribological behavior was investigated under as-cast and T6 heat-treated conditions. Wear rate increased linearly with sliding distance up to a certain limit and then increased significantly. At 40N load, a protective layer formed between the disk and pin surface, reducing coefficient of friction. The wear mechanism was abrasion and oxide. At higher loads, the protective layer disappeared, leading to increased coefficient of friction and wear mechanism of adhesion and delamination. Heat treatment improved the wear resistance of the alloy and nanocomposites due to matrix strengthening. The wear rate of Al matrix was reduced by the self-lubricating property of MWCNTs.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Mechanical
Sanyam Sharma, Sanjeev Lambah, Vinod Mittal, Rajiv Verma
Summary: This study focuses on the computation of static performance of partial journal bearings using micropolar lubricant. The lubricant flow is governed by the non-dimensional Reynolds equation and solved using the finite element method. Results show that larger bearing geometry and higher micropolar parameters enhance the static performance of the partial journal bearing system.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2023)
Article
Engineering, Mechanical
Huiyi Yang, Yang Xu, Chao Xu
Summary: This study focuses on the impact of dry friction interfaces on the dynamics of jointed structures, particularly on the statistics of contact pressure distribution. Through experimental and simulation analysis, it is found that surface roughness and contact load have significant effects on contact area, contact stiffness, and mean contact pressure.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Guanglan Hu, Houfu Dai
Summary: The effect of metal coating on the machinability of cubic silicon carbide was investigated using molecular dynamics simulation. The results showed that the type of coating has a significant impact on cutting force, surface morphology, stress, and tool wear. Among the three metals studied, Cu coating had the greatest impact on improving cutting performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yunfan Liu, Guozheng Ma, Lina Zhu, Cuihong Han, Zhen Li, Bin Zhang, Haichao Zhao, Haidou Wang, Shuying Chen
Summary: The service performance of coated self-lubricating spherical plain bearings can be improved by applying self-lubricating coatings, especially double-sided coatings. The presence of a large-area and complete mixed friction transfer film on the contact surfaces can cause a signal downstage before the signal mutation stage.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yakup Artun, C. Oktay Azeloglu, Gokhan Taylan
Summary: This article investigates the tribological properties of polymer journal bearings, particularly focusing on radial journal bearings made from UHMWPE and POM materials with different surface qualities. The study examines the performance of these bearings under varying load and speed conditions, and analyzes the relationship between material and surface roughness in tribological performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
