Article
Acoustics
Jie Yang, Rupeng Zhu, Heow Pueh Lee, Miaomiao Li, Xunmin Yin
Summary: This study establishes a coupled dynamic model considering the asymmetry and interaction of journal bearing parameters for a herringbone planetary gear train (HPGT). A gearbox casing condensation model is also proposed. The dynamic performances of the marine gearbox are explored under different conditions and parameters, providing a theoretical basis for optimal design.
JOURNAL OF SOUND AND VIBRATION
(2023)
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
Computer Science, Theory & Methods
Christian Legaard, Thomas Schranz, Gerald Schweiger, Jan Drgona, Basak Falay, Claudio Gomes, Alexandros Iosifidis, Mahdi Abkar, Peter Larsen
Summary: Dynamical systems are extensively used in natural sciences and engineering disciplines. While simple systems can be described by differential equations derived from fundamental physical laws, more complex systems require data-driven modeling approaches. This article surveys the use of neural networks to construct models of dynamical systems, reviews related literature, identifies significant challenges, and discusses promising research areas.
ACM COMPUTING SURVEYS
(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
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, Mechanical
Yu Huang, Haiyin Cao, Zhuxin Tian
Summary: This study found two threshold speeds for long journal bearing, and pointed out that stability boundary behaves differently when the rotating speed is different from short bearing.
Article
Engineering, Electrical & Electronic
Yandong Gu, Jinwu Cheng, Chaojie Xie, Longyu Li, Changgeng Zheng
Summary: This study investigates the static characteristics of aerostatic journal bearings with porous bushing. A flow model is established considering the compressibility of lubricating gas. The effects of nominal clearance and gas compressibility on the static characteristics are analyzed. The results show that increasing nominal clearance leads to higher load capacity, mass flow rate, and power consumption, while increasing gas polytropic index strengthens the load capacity but decreases the mass flow rate and power consumption.
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
Mathematics
Arzu Akbulut, Melike Kaplan, Rubayyi T. Alqahtani, W. Eltayeb Ahmed
Summary: The study investigates various soliton-type solutions to the complex Hirota-dynamical Model (HDM) using modified simple equation and generalized and modified Kudryashov approaches. Modulation instability (MI) analysis is also conducted, and visual representations for the HDM are provided.
Article
Mathematics, Applied
Mohanasubha Ramasamy, Suresh Kumarasamy, Ashokkumar Srinivasan, Pavithra Subburam, Karthikeyan Rajagopal
Summary: This study investigates the influence of higher-order interactions on network synchronization in fractional-order complex systems. The results show that higher-order interactions contribute to earlier synchronization, and lower fractional-order values accelerate the synchronization process. The findings are validated using multiple models.
Review
Computer Science, Interdisciplinary Applications
Rajeev Kumar Dang, Deepam Goyal, Amit Chauhan, S. S. Dhami
Summary: This paper provides a state-of-the-art review of various numerical and experimental studies conducted over the past two decades to enhance the tribological performance of journal bearings using different lubricants. Despite exemplary tribological performance, there is a dire need for computational methods to evaluate journal bearing performance considering the effects of nanolubricants.
ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING
(2021)
Article
Computer Science, Information Systems
Tengfei Yin, Guoqing Zhang, Jianjun Du, Suet To
Summary: This paper presents a nonlinear analysis of the stability and dynamic rotational accuracy of an unbalanced rotor supported by aerostatic journal bearings. Using a finite element method and Runge-Kutta fourth order method, the dynamic response of the rotor under varying rotor masses is analyzed. It is found that the dynamic responses strongly depend on the rotor mass, with different motion patterns observed as the mass changes.
Article
Engineering, Aerospace
Changbao Yang, Zhisheng Wang, Zhe Chen, Yuanwei Lyu, Jingyang Zhang
Summary: In this study, the fluid-structure interaction between the gas film and elastic foils in gas foil journal bearings was investigated. The results showed that the stable fluctuations of flow field parameters varied at different positions, and the oscillating duration in the solid domain was shorter than in the fluid domain. The presence of elastic foils flattened the distribution of gas film pressure and improved the stability of the shearing flow. The research laid the foundation for studying unsteady fluid-structure interaction.
Article
Automation & Control Systems
Lei Chen, Xinghuo Yu, Changyin Sun
Summary: This article provides a detailed mathematical proof of the characteristic modeling approach for high-order linear dynamical systems, explaining how high-order dynamics can be compressed into lower-order characteristic models. It also investigates the relationships between high-order linear continuous dynamical systems, discrete-time characteristic model coefficients, and sampling-time intervals.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2021)
Article
Engineering, Mechanical
Nicolas Perez, Cristian Rodriguez
Summary: Reliable operation of the hydropower unit in hydropower plants is critical, and a dynamic model can be used for condition monitoring and accurately predicting the operation and failure of the unit.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Green & Sustainable Science & Technology
Khalil Deghoum, Mohammed T. Gherbi, Muhsin J. Jweeg, Hakim S. Sultan, Azher M. Abed, Oday I. Abdullah, Necib Djilani
Summary: The paper designs and optimizes a 5 kW horizontal axis wind turbine blade model using a new MATLAB code based on blade element momentum theory. The aerodynamic shape is improved compared to the initial design, resulting in a 7% increase in power and an 8% increase in power coefficient. Finite Element Method, Computational Fluid Dynamics, and ANSYS software are used to calculate loads, simulate and optimize the blade structure. The optimized model reduces deflections by up to 42.85% and has a decreased mass of up to 71.24%.
INTERNATIONAL JOURNAL OF RENEWABLE ENERGY DEVELOPMENT-IJRED
(2023)
Article
Engineering, Manufacturing
M. N. Mohammed, M. Z. Omar, Adnan Naji Jameel Al-Tamimi, Hakim S. Sultan, Luay Hashem Abbud, Salah Al-Zubaidi, Oday I. Abdullah, M. Abdulrazaq
Summary: This study describes the solid-liquid structural changes and phase transformations that occur during the DPRM process in annealed D2 tool steel. The presence of undissolved carbide particles at 1250 degrees C gradually disappears as the temperature rises. The transformation of equiaxed grains to a globular structure improves the shape factor and grain size for thixoforming, resulting in enhanced mechanical properties.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2023)
Article
Computer Science, Information Systems
Osamah Fakhri, George Youssef, Somer Nacy, Adnan Naji Jameel Al-Tamimi, O. Hussein, Wisam T. T. Abbood, Oday Ibraheem Abdullah, Nazar Kais Al-Karkhi
Summary: This paper presents a systematic approach to achieve stable grasping of objects with a two-finger robotic hand filled with granular media. The compaction of the media, controlled by vacuum pressure, was used to adjust the finger's structural and contact stiffness. The study analyzed the grasping stability under the concurrent effect of external torque and applied vacuum pressure. Three control schemes were experimentally applied to ensure effective grasping. The results showed stable and unstable grasping regions for different combinations of torque and vacuum pressure. The two-finger robotic hand can be further improved for high load-carrying applications.
Article
Engineering, Mechanical
Hazim U. Jamali, Hakim S. Sultan, Oday I. Abdullah, Adnan Naji Jameel Al-Tamimi, Luay Hashem Abbud, Alessandro Ruggiero, Zahraa A. Al-Dujaili
Summary: This paper investigates the use of bearing chamfer to reduce the negative effects of misalignment in journal bearings. Linear and curved chamfering forms are considered and their effects on bearing performance are analyzed. The results show that both chamfer forms can reduce maximum pressure and coefficient of friction, increase film thickness levels, and extend the range of misalignment in which the bearings can operate safely.
Article
Engineering, Mechanical
Hazim U. Jamali, Hakim S. Sultan, Oday I. Abdullah, Adnan Naji Jameel Al-Tamimi, Murtadha M. Al-Masoudy, Alessandro Ruggiero, Maria Cristina Valigi
Summary: This paper investigates the problem of finite-length misaligned journal bearings, comparing the effects of general 3D misalignment and vertical misalignment problems for modified bearings. The results show that using a variable axial bearing profile can significantly improve bearing characteristics, such as increasing the minimum film thickness and reducing the pressure levels, as well as reducing the friction coefficient. Furthermore, the modification enhances the rotor-bearing stability under position perturbation, extending the speed range for safe operation.
Article
Computer Science, Information Systems
Khalil Deghoum, Mohammed Taher Gherbi, Hakim S. Sultan, Adnan Jameel N. Al-Tamimi, Azher M. Abed, Oday Ibraheem Abdullah, Hamza Mechakra, Ali Boukhari
Summary: The model of a 5 kW small wind turbine blade is developed and improved in this article. Efforts have been made to enhance the blade's efficiency and aerodynamics, as well as to select the optimal material. QBlade software is utilized to improve the chord and twist, while a new finite element model is developed using ANSYS software to analyze the structure and modal problems. The results show the von Mises stresses and deformations of the wind blade made of three different materials (Carbon/epoxy, E-Glass/epoxy, and braided composite), as well as the natural frequencies and mode shapes for each material. Based on the results, the maximum deflections are found to be 46.46 mm, 33.54 mm, and 18.29 mm for E-glass, braided composite, and carbon fiber, respectively.
APPLIED SYSTEM INNOVATION
(2023)
Article
Materials Science, Multidisciplinary
H. S. Aljibori, O. H. Abdulzahra, A. J. Al Adily, W. K. Al-Azzawi, A. A. Al-Amiery, A. A. H. Kadhum
Summary: This review paper summarizes the recent advancements in using thiadiazole derivatives as corrosion inhibitors in hydrochloric acid solutions. The properties and effectiveness of these derivatives as corrosion inhibitors, including their molecular structure and mechanism of action, are discussed. The paper also highlights their applications in controlling corrosion in various metal substrates in hydrochloric acid solutions and compares their performance with traditional corrosion inhibitors. Overall, the paper provides a comprehensive overview of the recent advances in using thiadiazole derivatives as corrosion inhibitors and their potential for future applications.
INTERNATIONAL JOURNAL OF CORROSION AND SCALE INHIBITION
(2023)
Article
Materials Science, Multidisciplinary
H. S. Aljibori, O. H. Abdulzahra, A. J. Al Adily, W. K. Al-Azzawi, A. A. Al-Amiery, A. A. H. Kadhum
Summary: This article investigates the corrosion inhibition ability of 2-oxo-3-hydrazonoindoline (OHI) on mild steel in 1.0 M hydrochloric acid. The results show that OHI has the highest inhibitory efficiency at a concentration of 0.5 mM and a temperature of 303 K, with an inhibition rate of 91.8%. The excellent inhibition properties of OHI are attributed to the presence of nitrogen, oxygen, benzene, and heterocyclic rings in its molecular structure. Additionally, longer immersion times enhance the inhibitory efficacy, while higher temperatures slightly reduce it.
INTERNATIONAL JOURNAL OF CORROSION AND SCALE INHIBITION
(2023)
Article
Thermodynamics
Iman Q. Al Saffar, Hakim S. Sultan, Muhsin Jaber Jweeg, Azher M. Abed, Oday I. Abdullah, Josef Schlattmann, Laith A. Sabri, Raed H. C. Alfilh
Summary: There are various essential demands in designing frictional clutches. The main purpose of this mechanical part is to transfer torque between driving and driven shafts. The engagement process of the clutch should be as short as possible to minimize power losses and achieve the desired speed. High contact stresses generated during sliding in the frictional clutch result in significant thermal fields.
HEAT TRANSFER RESEARCH
(2023)
Article
Engineering, Mechanical
Alessandro Ruggiero, Marco De Stefano
Summary: This study investigates the tribocorrosive behavior of two common biomaterials used in dentistry, Titanium Grade V and Steel 316 L. The experiments reveal that higher pH and NaCl concentration result in greater material loss, particularly in terms of mechanical-chemical combined action, which significantly contributes to total wear. Furthermore, Titanium Grade V alloy exhibits superior tribocorrosive wear resistance compared to Steel 316 L due to its higher hardness. Lastly, a linear correlation between tribocorrosive current and synergistic factor is discovered, which could be utilized in future analytical wear models.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Salah Al-Zubaidi, Jaharah A. Ghani, Che Hassan Che Haron, Adnan Naji Jameel Al-Tamimi, M. N. Mohammed, Alessandro Ruggiero, Samaher M. Sarhan, Oday I. Abdullah, Mohd Shukor Salleh
Summary: This study investigates the impact of dry-end milling with an uncoated tool on the surface roughness of titanium alloy, as well as develops a new neural model to optimize the milling process. The experimental results demonstrate that the feed rate has the largest influence on the surface roughness. The optimal milling parameters can yield the minimum surface roughness. Additionally, the BPNN-PSO-GSA hybrid model shows better performance in terms of mean square error compared to the BPNN-PSO model.
JOURNAL OF THE MECHANICAL BEHAVIOR OF MATERIALS
(2023)
Review
Materials Science, Multidisciplinary
H. S. Aljibori, A. Alamiery, A. A. H. Kadhum
Summary: This comprehensive review provides an overview of recent advances in corrosion protection coatings, focusing on organic, inorganic, and metallic coatings. It discusses the fundamentals of corrosion protection coatings and highlights recent advancements in different types of coatings. The paper also presents evaluation methods for coating performance and testing, as well as the wide-ranging applications of corrosion protection coatings in various industries.
INTERNATIONAL JOURNAL OF CORROSION AND SCALE INHIBITION
(2023)