Article
Engineering, Mechanical
S. Boedo
Summary: This study investigates the impact of surface ellipticity on self-acting partial arc journal bearings under steady load and sinusoidal oscillation, taking into account mass conserving cavitation. The computational efficiency is improved by using a generalized Warner bearing (GWB) formula. The results demonstrate that an elliptical sleeve can significantly improve bearing performance at small oscillation amplitudes commonly found in practical applications, and a fully hydrodynamic lubrication regime can be established through the wearing-in process of the sleeve surface.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Electrical & Electronic
Guglielmo Giannetti, Enrico Meli, Andrea Rindi
Summary: Tilting pad journal bearings (TPJBs) are important components in modern rotating machines. This study proposes an innovative modeling approach based on efficient flexible multibody techniques to describe the behavior of TPJBs. The model is tested on a real TPJB geometry and validated through experimental tests, showing encouraging results. The proposed model can be applied in various engineering fields such as Oil & Gas and aeronautics.
Article
Mechanics
Chunxiao Bi, Dongjiang Han, Yao Wu, Yimin Li, Jinfu Yang
Summary: A global heat balance method for supercritical carbon dioxide (S-CO2) high speed tilting pad bearings was developed, taking into consideration the real gas effect, variable thermodynamic properties, and turbulence effect. The influence of the thermal effect on the static and dynamic characteristics of bearings is caused by changes in density, specific heat, and thermal expansion coefficient rather than viscosity, which is different from oil bearings. The study found that the influence of thermohydrodynamic lubrication on static characteristics of S-CO2 tilting pad bearings is more significant than on dynamic coefficients.
Article
Engineering, Mechanical
Bei Yan, Lei Dong, Ke Yan, Fei Chen, Yongsheng Zhu, Dongfeng Wang
Summary: High precision models were used to study the airflow pattern and lubrication performance inside bearing cavity under different oil-air supply methods. The Level-Set function and VOF method were employed to track the oil-air interface and the migration and diffusion process of oil droplets. A high-speed oil-air lubrication test rig was set up to test and compare bearing temperature rise with different lubrication methods at varying rotation speeds, while synergistic analysis was applied to estimate lubricant flow and heat dissipation performance in key areas.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Mechanics
S. Y. Chien, M. S. Cramer
Summary: This article presents a detailed derivation of the Reynolds equation and its corresponding energy equation for three-dimensional, steady, laminar, compressible flows of single-phase Navier-Stokes fluids in thrust bearings. The validity of these equations is shown for most of the dense and supercritical gas regime, except near the thermodynamic critical point. It is found that the effective bulk modulus is the primary thermodynamic function governing the lubrication flow of high-pressure gases. Numerical and approximate solutions are obtained for moderate and high-speed flows, taking into account the formation of boundary layers.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Mechanical
Robin M. Robrecht, Peter F. Pelz
Summary: The present study investigates the influence of the Lomakin effect on stationary bearing performance and proposes a new model that accounts for fluid inertia. The results demonstrate the crucial role of accurately treating the Lomakin effect for prediction accuracy.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Guanying Xing, Song Xue, Jiacheng Han, Huaiyu Zuo, Run Hu, Zhengkai Tu, Xiaobing Luo
Summary: This paper studies the flow behavior of magnetorheological fluid in the clearance and its influence on the flow object, and proposes a flow dynamics and strain distribution model to predict the pressure distribution and lubrication characteristics.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Guojun (Gary) Ren
Summary: This paper uses equation-based finite element analysis to provide a new method for calculating the performance of journal bearings with deformable surfaces, which is crucial for water lubricated bearings made of polymers. The study introduces a new sub lubrication regime and distinguishes between Hypo-Elastohydrodynamic and Elastohydrodynamic Lubrication, and introduces several new concepts to describe bearing performance.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Luis Fernando dos Anjos, Alfredo Palma Jaramillo, Gustavo Carlos Buscaglia, Rodrigo Nicoletti
Summary: The manufacturing of texture patterns on the surfaces of lubricated bearings is an interesting way to improve their tribological behavior. Depending on the texture geometry, it can reduce friction or increase load-carrying capacity. This study investigates the effects of texturing the rotating surface of journal bearings' lubricated contact.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Mingchen Qiang, Qi Zhao, Shaohang Yan, Xue Liu, Yu Hou, Tianwei Lai
Summary: The liquefaction of hydrogen plays a crucial role in the large-scale utilization of hydrogen energy. The performance of the hydrogen turbo-expander, a key refrigerating machine for high liquefaction efficiency, is directly affected by the hydrogen gas bearings. By numerically calculating and comparing the characteristics of herringbone grooved journal bearings under different lubricating gases, the study provides insights into the performance of hydrogen gas bearings. It is found that the performance of hydrogen gas bearings can be improved by adjusting working conditions, leading to increased load capacity and enhanced dynamic stability.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Multidisciplinary
M. B. Badawi, Taher H. Awad, I. M. El Fahham
Summary: This study applies artificial intelligence techniques to predict the performance of a plain journal bearing, showing their superiority over classical methods in terms of accuracy and speed. The data required for AI prediction is obtained using the finite difference method, and artificial neural networks and fuzzy logic techniques are utilized for performance parameter prediction.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Jintao Lei, Bing Su, Shuailong Zhang, Haisheng Yang, Yongcun Cui
Summary: This paper mainly investigates the temperature rise characteristics of high-speed angular contact ball bearings under operational conditions from the perspective of dynamics. A steady-state calculation model of the bearing is established using a thermal network method, taking into account the influence factor of friction power consumption in bearing components based on a dynamic model. The steady-state change characteristics of the bearing are obtained by solving a thermal balance equation, and the influence laws of bearing rotation speed, oil supply, and environmental temperature on the friction temperature rise are analyzed. Finite element analysis software ANSYS is employed for comparative verification, showing good agreement with the dynamics-based thermal analysis in terms of speed-temperature variation tendency.
Article
Engineering, Mechanical
Jacopo Tacconi, Shahrokh Shahpar, Andrew King, Johannes Paulus Olufeagba, Raymarn Khan, Ian Sant, Martin Yates
Summary: Gear pumps are widely used in aero-engine fuel systems, and the design and analysis of hybrid journal bearings used in these pumps pose challenges. A numerical model has been developed to evaluate and design the pressure distribution of hybrid journal bearings for fuel pump applications. The tool has been validated and shows good accuracy and robustness.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Guoqing Xiong, Zhiwei Mao, Jinjie Zhang, Zijia Wang, Huailei Wang, Zhinong Jiang
Summary: Numerous studies have shown that both journal misalignment and bearing elastic deformation significantly affect lubrication performance. Recent research indicates that viscoelastic deformation is more useful than elastic deformation for determining the effects of strong impact loads. However, there have been no studies on the coupled effects of misalignment and viscoelastic deformation. Therefore, this study proposes a novel transient lubrication model that considers the influences of both misalignment and viscoelastic deformation, and investigates their coupled effects on lubrication performance.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Carlos Alberto Alves Viana, Diogo Stuani Alves, Tiago Henrique Machado
Summary: This paper discusses the applicability of linear/nonlinear methods for representing the dynamics of hydrodynamic bearings in rotor dynamics. Numerical simulations were performed using a computational model, and the responses of linear and nonlinear models were compared. The results showed that trilobed bearings are more susceptible to nonlinear effects, which is important for fault diagnosis in the field of structural health monitoring.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Multidisciplinary
M. Moradi, F. Colombo, T. Raparelli, A. Trivella, V. Viktorov
PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY
(2019)
Article
Mechanics
F. Colombo, F. Della Santa, S. Pieraccini
JOURNAL OF MECHANICS
(2020)
Article
Automation & Control Systems
Marco Pontin, Federico Colombo, Luigi Mazza, Terenziano Raparelli
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING
(2020)
Article
Engineering, Mechanical
Danial Ghodsiyeh, Federico Colombo, Luigi Lentini, Terenziano Raparelli, Andrea Trivella, Vladimir Viktorov
TRIBOLOGY INTERNATIONAL
(2020)
Article
Chemistry, Multidisciplinary
Federico Colombo, Luigi Lentini, Andrea Trivella, Terenziano Raparelli, Vladimir Viktorov
Summary: The paper discusses the application of aerostatic spindles in high-speed micromachining and validates the developed non-linear numerical model through experiments. A method is proposed to identify the main modal parameters of the spindle and potential sources of uncertainty are speculated.
APPLIED SCIENCES-BASEL
(2021)
Editorial Material
Chemistry, Multidisciplinary
Federico Colombo, Luigi Lentini, Terenziano Raparelli, Andrea Trivella
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Mechanical
Federico Colombo, Luigi Lentini, Terenziano Raparelli, Andrea Trivella, Vladimir Viktorov
Summary: This paper focuses on the unbalance response of a high-speed spindle system supported by gas journal bearings, discussing multiple aspects to enhance system accuracy and using validated nonlinear and linearized numerical models.
Proceedings Paper
Green & Sustainable Science & Technology
Federico Colombo, Luigi Lentini, Terenziano Raparelli, Andrea Trivella
Summary: This paper describes the environmental advantages of gas bearings and their challenging application domains. It also provides a survey on all types of gas bearings, discussing their pros and cons.
PROCEEDINGS OF I4SDG WORKSHOP 2021: IFTOMM FOR SUSTAINABLE DEVELOPMENT GOALS
(2022)
Article
Engineering, Mechanical
Federico Colombo, Luigi Lentini, Terenziano Raparelli, Andrea Trivella, Vladimir Viktorov
Summary: Aerostatic bearings are suitable for high-precision applications, but have low relative stiffness and poor damping due to lubricant compressibility. This paper presents a design procedure for passively compensated bearings controlled by diaphragm valves to maximize stiffness. The designed bearings exhibit quasi-static infinite stiffness within a certain load range.
Article
Engineering, Mechanical
Federico Colombo, Luigi Lentini, Terenziano Raparelli, Andrea Trivella, Vladimir Viktorov
Summary: This paper presents a hybrid method to identify the discharge coefficients of aerostatic bearing orifices, which is accurate and practical compared to conventional methods.
Proceedings Paper
Engineering, Electrical & Electronic
F. Colombo, L. Mazza, G. Pepe, T. Raparelli, A. Trivella
ADVANCES IN SERVICE AND INDUSTRIAL ROBOTICS, RAAD 2018
(2019)
Proceedings Paper
Engineering, Electrical & Electronic
F. Colombo, L. Lentini, T. Raparelli, A. Trivella, V. Viktorov
ADVANCES IN SERVICE AND INDUSTRIAL ROBOTICS, RAAD 2018
(2019)
Article
Automation & Control Systems
Daniela Maffiodo, Federico Colombo, Terenziano Raparelli
INTERNATIONAL JOURNAL OF AUTOMATION TECHNOLOGY
(2019)
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)
