Article
Engineering, Mechanical
Dimitrios Skaltsas, Georgios N. Rossopoulos, Christos Papadopoulos
Summary: This study presents a novel solution for hydrodynamically lubricated bearings with stochastic roughness. By utilizing stochastic analysis and theory, an advanced form of Reynolds type Equation is derived. The proposed methodology is validated against relevant literature works and applied to characterize the tribological performance of bearings with different roughness profiles.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
I. C. M. Filgueira Filho, A. C. Bottene, E. J. Silva, R. Nicoletti
Summary: Research shows that in textured journal bearings, the Chevron pattern and the oblong dimple pattern have significant effects on bearing performance, which can be either positive or negative.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Lili Wang, Wei Zhang, Xingtang Zhao, Xue Ge
Summary: This paper studies the influence of microtexture size, shape, and direction on lubrication performance, and proposes oil film thickness equations and wear calculation equations considering the microtexture. The research finds that appropriate microtexture shapes can effectively improve the lubrication performance of journal bearing and reduce the friction coefficient.
INDUSTRIAL LUBRICATION AND TRIBOLOGY
(2022)
Article
Mechanics
Giovanni Cimatti
Summary: Porous metal bearings are commonly used in small and micro devices, and the pressure in a porous bearing is found to be lower than in a non-porous bearing. The study focuses on solving the Reynolds equation coupled with the Laplace equation to compute the pressure, and introduces a variational formulation for the relevant boundary value problem.
Article
Computer Science, Interdisciplinary Applications
Elia Iseli, Juerg Schiffmann
Summary: This study utilizes neural network regression models to predict gas journal bearing reaction forces and accelerate the computation process; modeling is done through FNN to replace traditional solutions and greatly improve computing speed; significant reduction in optimization time for rotor systems is achieved.
JOURNAL OF COMPUTATIONAL SCIENCE
(2021)
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
Engineering, Mechanical
Shi Chen, Nian Yin, Xiaojiang Cai, Zhinan Zhang
Summary: The study focuses on a discretization formula of the Reynolds equation based on the Crank-Nicolson method, utilizing Gauss-Seidel relaxation and distribution relaxation for the linear operators of pressure. An estimation framework is developed to investigate the relative error in the Reynolds equation. Experimental results show that the proposed method performs well in handling contact and wavy surfaces.
FRONTIERS OF MECHANICAL ENGINEERING
(2021)
Article
Multidisciplinary Sciences
Ali Abbaspur, Mahmood Norouzi, Pooria Akbarzadeh, Seyyed Amirreza Vaziri, Melika Mokhtari Sharghi, Kyung Chun Kim, Mirae Kim
Summary: This paper presents a novel analytical solution for journal-bearing viscoelastic lubrication using the perturbation method. The investigation focuses on the impact of characteristic parameters such as mobility factor, eccentricity ratio, and Weissenberg number on the fluid film pressure distribution, load capacity, and shear stress.
SCIENTIFIC REPORTS
(2023)
Article
Metallurgy & Metallurgical Engineering
Dong-xing Tang, Lei Yin, Bin Xiao, Yan-feng Han, Guo Xiang, Jia-xu Wang
Summary: The present study aims to establish a mixed lubrication model for coupled bearings used in ship shaftless rim-driven thrusters. Based on numerical results, the optimal bottom shape and tilting angle of the bearing have been determined, with the coupled bearing having a left triangle microgroove bottom shape exhibiting the best lubrication performance.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2022)
Article
Engineering, Mechanical
Gabriel W. Rodrigues, Fabiano L. Oliveira, Llmar F. Santos, Marco L. Bittencourt
Summary: This paper compares different dynamical models, cavitation procedures, and numerical methods for simulating hydrodynamic lubricated bearings of internal combustion engines. The study found that different dynamical models differed in predicting journal orbits, while the finite element method with Giacopini's cavitation model showed improved numerical stability for the three types of engines.
INDUSTRIAL LUBRICATION AND TRIBOLOGY
(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
Ning Ding, Shebin Yan, Gaozhang Ma, Hulin Li, Dan Jiang
Summary: This paper proposes an adaptive iterative method based on a mixed thermo-elasto-hydrodynamic (TEHD) lubrication and wear coupling model to investigate the lubrication and wear behaviors of journal bearings in the mixed lubrication. The evolution laws of the oil film thickness, the hydrodynamic pressure, the asperity contact pressure, the friction power loss, and the wear distribution are discussed and compared under different running times, oil temperatures, external loads, and shaft rotational speeds. The three-dimensional surface models based on the asperity contact power loss and the maximum wear depth with the variation of the running time and the oil temperature are fitted under specific external loads and shaft rotational speeds.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Multidisciplinary
Jonatha Reis, J. P. Moitinho de Almeida, Pedro Diez, Sergio Zlotnik
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2020)
Article
Engineering, Multidisciplinary
J. P. Moitinho de Almeida, Jonatha Reis
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2020)
Article
Engineering, Multidisciplinary
Jonatha Reis, J. P. Moitinho de Almeida, Pedro Diez, Sergio Zlotnik
Summary: In this work, compatible and equilibrated PGD solutions are computed and used in a dual analysis to obtain quantities of interest and their bounds with guaranteed accuracy. Complementary solutions are also used to compute an error indicator, driving a mesh adaptivity process focused on minimizing errors in the quantity of interest. The proposed approach results in lower errors compared to uniform refinement or global error-based indicators.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
J. P. Moitinho de Almeida, Jonatha Reis
Summary: We propose a methodology to define the matrices used in stress based finite element approximations for three-dimensional problems. By rotating the global reference frame, the increased complexity of the 3D case is greatly simplified. This rotation can also be applied to the 2D case. The focus of this work is on the matrices used in the implementation of the hybrid equilibrium approach, but we also present a complementary displacement-based methodology for efficiently defining the matrices required for dual analysis.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
