Article
Engineering, Mechanical
Shouan Chen, Guo Xiang, Michel Fillon, Juan Guo, Jiaxu Wang, Jianlin Cai
Summary: This paper investigates the impact of imperfect journal on the tribo-dynamic behavior of water-lubricated bearings during start-up. The numerical model shows that the shape error of the journal can affect the performance of the bearing, but within a reasonable range, it can also improve the tribological performance.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Thermodynamics
Xiaojun Shi, Yingjie Mu, Gangqing Chen, Xiaodong Zhang
Summary: The study found that under high FR conditions, when the heat load is low, the SLTP exhibits intermittent boiling. Additionally, at high heat loads, the SLTP under high FR conditions transitions from natural convection to boiling during startup.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Mechanical
Guo Xiang, Cheng Wang, Yijia Wang, Yanfeng Han, Jiaxu Wang, Zhongliang Lv
Summary: This study established a DMEHL model that couples the rotor dynamic model considering unbalanced load with the transient mixed lubrication model. The research found that during start-up, rotor dynamic characteristics and hydrodynamic force are more sensitive to unbalanced load than transient contact force, and DMEHL performance at the start-up stage highly depends on the elastic modulus and hardness of water-lubricated materials.
TRIBOLOGY TRANSACTIONS
(2021)
Article
Engineering, Multidisciplinary
Xingbao Huang, Xiao Zhang, Youqiang Wang
Summary: Ferromagnetic ferrofluids have excellent tribological characteristics for mechanical applications. Utilizing ferrofluid lubrication in start-up motion can improve severe wear of rough elliptical contact. The effects of ferromagnetic particle size and magnetic field intensity on wear reduction are significant.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Engineering, Mechanical
Guangwu Zhou, Kepeng Wu, Wei Pu, Peng Li, Yanfeng Han
Summary: This paper investigates the modification effects of different nano-fillers on the basic formulation of hydrogenated nitrile rubber (HNBR). The results show that UHMWPE and GF have different improvements on the tribological performance of rubber materials under different speed conditions. To achieve the best comprehensive performance, appropriate nano-fillers should be selected for modification according to the operating conditions.
Article
Engineering, Mechanical
Qilin Liu, Wu Ouyang, Qichao Cheng, Jinjun Li, Qizhi Cheng, Ruiqing Li
Summary: This paper investigates the lubrication and dynamic characteristics of water-lubricated stern bearing under service conditions. It proposes a test scheme to analyze the pressure distribution and spatial shaft position of the bearing. The experiment reveals the pressure bias and bidirectional shaft inclination phenomenon, and a dynamic model considering bidirectional shaft inclination and lining deformation is established. The study explores the influences of various factors on lubrication and dynamic characteristics and provides guidance for the design and optimization of such bearings.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Mechanics
Jianlin Cai, Yanfeng Han, Guo Xiang, Jiaxu Wang, Liwu Wang
Summary: This study investigates the effects of wear and shaft-shape error defects on the tribo-dynamic responses of water-lubricated bearings under nonlinear propeller disturbance. The results show that the nonlinear disturbance significantly affects the dynamic behavior of the bearings, and reasonable wear parameters can improve the lubrication performance.
Article
Engineering, Mechanical
Jaroslav Zapomel, Petr Ferfecki
Summary: The paper presents a new design concept for a hydrodynamic bearing lubricated by composite magnetic fluids. The mathematical model and computational procedures were developed to study the behavior and performance of the bearing. The research shows that increasing the magnetic induction in the bearing gap improves the bearing load capacity and centers the journal. The advantage of this bearing is its semiactive operation principle.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Mechanical
Hui Cen, Piet M. Lugt
Summary: The impact of start-stops on the thickness of lubricating films in grease lubricated rolling bearings differs from that in oil lubricated bearings. The film thickness quickly drops to zero during a stop and unexpectedly increases to a large value when started again, due to additional track replenishment during the stop.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Mechanics
Jianlin Cai, Guo Xiang, Sheng Li, Juan Guo, Jiaxu Wang, Shouan Chen, Tianyou Yang
Summary: This paper develops a mathematical model to investigate the nonlinear dynamic mixed friction behaviors of a novel coupled bearing lubricated with low-viscosity fluid. The study reveals the effect of structural parameters on the friction behavior and verifies the model through numerical simulations.
Article
Thermodynamics
Zhitao Wang, Jingkai Zhang, Chuming Gao, Liang Ming
Summary: A new method for simulating the transient performance of engine start-up process is presented in this paper, and the effects of ambient humidity and temperature on the matching process between the engine and starter are investigated. By establishing a power compatibility equation between the turbofan engine and starter, the start-up performance under different environmental conditions is predicted.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Li Qin, Hongling Qin, Jing Tang Xing
Summary: Based on the energy flow theory of nonlinear dynamical system, this paper investigates the stabilities, bifurcations, and possible periodic/chaotic motions of nonlinear water-lubricated bearing-shaft coupled systems. It reveals that the system behaves in three different types around the equilibrium point with different friction parameters, leading to distinct dynamic behaviors such as stable, unstable, and local phase space division.
ACTA MECHANICA SINICA
(2021)
Article
Chemistry, Multidisciplinary
Yanfeng Han, Ting Tang, Guo Xiang, Hang Jia
Summary: This study investigates the impact of propeller shaft deflection on the fluid-solid-heat coupling performance of water lubricated rubber stern bearing, and develops a model to validate the findings. Results suggest that under heavy load conditions, the deflection of the stern shaft should be taken into account in the analysis of FSH performance of the JWR system.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Chemical
Can Ma, Qichao Yang, Xiaohang Sun, Kelong Zhang, Liansheng Li
Summary: In this study, the performance of an externally pressurized gas journal bearing lubricated with R134a vapor in an oil-free refrigeration centrifugal compressor is investigated using the finite difference method (CFD) to solve the Reynold equations. The load capacity, stiffness, and mass flow rate of the refrigerant vapor are obtained under various operational parameters and compared with those in air gas bearings. The effects of average clearance, eccentricity ratios, and supply vapor pressure on the static characteristics of journal bearings are discussed in detail. The study concludes that the optimal operational parameters for R134a vapor gas journal bearings are different from air journal bearings, and these factors should be considered in the design process.
Article
Engineering, Marine
Rui Li, Ji Wang, Ziqi Chen, Feixiang Wang, Yujun Liu
Summary: The quality of shafting alignment is crucial for the reliability and safety of ship operations, and bearing displacement adjustment plays a key role in shafting alignment. This study focused on investigating a strain gauge method-based shafting load measurement system, using a quadratic programming-based optimization method to calculate the adjustment, and adopting algorithms based on bearing load influence coefficients to forecast the load after adjustment. Experimental work and analysis of real ships confirmed the significance of the measurement, optimization, and forecasting methods for guiding ship shafting alignment in actual construction.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Mechanical
Busra Duran, Jerome Cavoret, David Philippon, Fabrice Ville, Arnaud Ruellan, Frank Berens
Summary: This study analyzes the changes in the physicochemical properties and tribological performances of gear transmission oils during field operation, finding differences from traditional engine oils.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Baocheng Liu, Hongsheng Chen, Jun Zhou, Jing Wang, Wenxian Wang, Xiaochun Chen, Sanxiao Xi
Summary: This study used fast hot pressing sintering to fabricate WC/AlCoCrFeNi2.1 metal matrix composites (MMCs). It was found that the addition of reinforced particles increased the microhardness, nanoindentation and wear resistance of the MMCs. During frictional processes, an oxide film formed, providing material protection, enhancing stability and reducing friction-induced losses.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Pradip Kumar Verma, Alok Singh
Summary: This study investigates the mechanical properties and wear resistance of CoMoMnNiV high entropy alloy reinforced aluminium matrix composite processed through stir-squeeze casting assisted with an ultrasonic transducer. The results show significant improvements in mechanical properties and wear resistance, with the composite containing 8 wt% HEA demonstrating the highest resistance to wear. Optical microscopy, SEM, and an optical profilometer were used for a thorough examination of the microstructure and worn surface.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Zhenghai Yang, Yingjian Song, Jinlong Jiao, Wenbo Li, Bao Shangguan, Yongzhen Zhang
Summary: This study investigated the friction, wear properties, and current-carrying properties of copper-graphite composites paired with brass C28000. The results showed that the current-carrying properties of the composite materials were excellent, but their wear rate was the main limiting factor. Furthermore, an increase in the thickness of the graphite layer led to an improvement in the uniformity of damage.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Moustafa Mahmoud Yousry Zaghloul, Karen Steel, Martin Veidt, Michael T. Heitzmann
Summary: This research evaluates and compares the impact of different material types on the tribological characteristics of Polyamide 6 composites, and finds that glass fiber-reinforced Polyamide 6 exhibits better friction and wear performance under high-pressure velocity factors.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Shaoqing Qin, Lida Zhu
Summary: In this paper, the surface and subsurface damage of laser assisted grinding CrCoNi medium entropy alloys were investigated using molecular dynamics simulations. The results showed that the application of laser energy can reduce cutting forces and minimize subsurface damage.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Kaikui Zheng, Youxi Lin, Tingzheng Lai, Chenghui Gao, Ming Liu, Zhiying Ren
Summary: The study investigated the use of waste foundry resin-bonded sand as a substitute for copper in resin-based brake material. It found that the waste sand was more favorable for improving the overall friction and wear properties of the material compared to copper. Waste sand benefited the material by forming a friction layer, leading to increased friction coefficient and stability. Brake material with 10-15% waste sand showed excellent heat-fade resistance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Dayang Li, Fanhao Zhou, Yutong Gao, Kun Yang, Huimin Gao
Summary: This article introduces a continuous prediction model based on deep learning for predicting the power output of steam turbines. The model uses long short term memory (LSTM) method to develop a trend prediction model and optimizes the prediction model through feature selection method. Experimental results show that the model outperforms other models in terms of prediction performance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Tomohiro Toyoda, Ryo Yasuike, Toshihiro Noda
Summary: In this study, a elasto-plastic constitutive model of friction incorporating the concept of superloading surface was developed based on the subloading friction model. The proposed model achieves a smooth transition of friction by describing the evolution rule of structure, treating the state with static friction coefficient larger than kinetic friction coefficient as the bulkiness of structure. The positive definiteness of the plastic multiplier, loading condition, and material parameters were derived, and the validity of the proposed model in accordance with the subloading-friction model was confirmed through a stick-slip simulation of a mass-spring system.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
P. Balaji, B. Surya Rajan, K. Sathickbasha, P. Baskara Sethupathi, Deviga Magadevan
Summary: This study emphasizes the importance of using a variety of solid lubricants with different oxidation temperature regimes to enhance the tribological performance of brake pads.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Jian Ma, Yancong Liu, Javad Mostaghimi, Na Zhang
Summary: This paper investigates the influence of preparation strategies on the lubrication properties of surface textures. Three laser scanning strategies are proposed to achieve a sinusoidal textured surface, and the evolution of surface structure and chemical composition is discussed. The findings show that ridge structures enhance anti-wear properties but also increase the friction coefficient. However, the oil cover preparation method prevents the formation of ridges and improves wettability.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Mohammad Roostaei, Arvin Taghizadeh Tabrizi, Hossein Aghajani
Summary: In this research, the Al2O3/MoS2 nanocomposite coating layer was successfully applied on the surface of Ti-6Al-4 V alloy. The relation between the surface characteristics and wear resistance of the coating was studied using atomic force microscopy analysis and pin-on-disk wear test method. The results showed that the nanocomposite coating significantly reduced the wear rate and provided an equation to calculate the Lancaster coefficient.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Musa Bilgin, Sener Karabulut, Halil Karakoc, Yunus Kayir, Murat Sarikaya
Summary: This study investigates various methods to improve the machinability efficiency of Inconel 718 alloy while considering their effect on microstructural properties. The results show that hot+PMQL, hot+SiCNMQL, and hot+Al2O3-NMQL contribute significantly to the improvement of machinability characteristics. The EBSD analysis also reveals that a limited area is affected by heat in the hot machining environment and that the removal of the heated layer during milling process helps preserve the microstructure.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Q. Gao, Y. Fan, Y. G. Wu, J. L. Liu, J. Wang, L. Li
Summary: Fretting wear significantly affects the hysteresis behavior of the contact surface and leads to joint degradation. This study investigates the influence of harmonic normal force on the evolution of interface morphology and contact parameters with fretting wear. The results show that the harmonic normal force can significantly influence the hysteresis loop and the energy dissipation distribution on the contact surface.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Benjamin Weiland, Floriane Leclinche, Anis Kaci, Brigitte Camillieri, Betty Lemaire-Semail, Marie -Ange Bueno
Summary: This study presents a systematic approach to generating control signals for a tactile simulator that simulate the touch of textile fabrics. By using a friction modulation tactile surface and acquiring forces from real surfaces with artificial finger mimicking fingerprints, control signals are generated and processed in the frequency domain before sending them to the tactile stimulator. The study focuses on the potential benefits of incorporating fingerprint information in fabric simulations to achieve a more realistic tactile perception. A sensory analysis with 36 participants using the generated control signals showed better discrimination without fingerprint information.
TRIBOLOGY INTERNATIONAL
(2024)