Article
Engineering, Mechanical
M. Wodtke, W. Litwin
Summary: The research focuses on thermal phenomena related to the operation of a water-lubricated stern tube bearing with axial grooves. Experimental tests showed that the intensity of forced axial flow significantly affects the bush temperature. Numerical simulations revealed that restricted axial flow leads to backflow of water through the grooves, resulting in a higher backflow temperature than the supply temperature and an increase in bearing bush temperature.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Tao He, Zhongliang Xie, Xin Tao, Kang Yang, Jian Jiao, Minli Huang, Wensheng Ma
Summary: This study proposes a water-lubricated stern bearing with self-adaptation capacity for load equalization and vibration reduction. By using elastic elements and damping alloy, the bearing can improve the service life and reduce vibration response.
Article
Chemistry, Analytical
Jinjun Li, Wu Ouyang, Qilin Liu, Zhuo Zhang, Yan Zhang
Summary: In this paper, an experiment on water-lubricated stern bearing (WSB) is conducted, and a bearing film-thickness identification model is established. The distributed lubrication characteristics of WSB under different speeds are systematically analyzed. The results show that the maximum identification error of the model is less than 7%, the lubrication state of the bearing changes dynamically with speed, and the area of each lubrication sub-region varies nonlinearly.
Article
Engineering, Mechanical
Qilin Liu, Wu Ouyang, Ruiqing Li, Yong Jin, Tao He
Summary: This paper aims to study the demand of underwater vehicles for water-lubricated stern bearings with low noise, low vibration, high load capacity, and long service life. A series of experiments was conducted to analyze the lubrication and vibration characteristics of three test bearings with different bushing materials and structures. The results indicate that under extreme working conditions, the modified polyurethane bearing shows the best comprehensive performance. Specific pressure and environment temperature significantly influence the bearing performance, while flow rate has limited effect. The research provides important references for the material and structure design and performance testing of water-lubricated stern bearings.
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, Mechanical
Xiaohui Lin, Shun Wang, Shuyun Jiang, Shaowen Zhang
Summary: This study investigates the influence of interface effect and cavitation bubble distribution on the dynamic characteristics of high-speed water-lubricated spiral groove thrust bearings. A turbulent cavitating flow lubrication model is established based on two-phase fluid and population balance equation of bubbles. The stiffness and damping coefficients of the bearings are calculated using perturbation pressure equations. Experimental results validate the theoretical model. The findings suggest that the turbulent effect has a greater impact on the dynamic characteristics of the bearings compared to the cavitation effect.
CHINESE JOURNAL OF MECHANICAL ENGINEERING
(2022)
Article
Engineering, Marine
Junchao Zhu, Guangcheng Wei, Zilong Peng, Zhaowang Xia, Liangyan Zheng, Hanhua Zhu
Summary: This paper investigates the impact of underwater explosion shock on the lubrication performance of ship stern bearings. A coupling model of shaft longitudinal vibration and bearing lubrication is established, and the influencing factors are analyzed.
INTERNATIONAL JOURNAL OF NAVAL ARCHITECTURE AND OCEAN ENGINEERING
(2022)
Article
Engineering, Mechanical
Zhongliang Xie, Jian Jiao, Kang Yang, Tao He, Rugang Chen, Weidong Zhu
Summary: The high temperature liquid Lead-Bismuth (PbBi) solution lubricated bearing plays a crucial role in the two-circuit main loop system of nuclear power stations. This study developed revised dynamic lubrication models considering cavitation effects and investigated the influences of clearances, rotating speeds, eccentricity ratios, and annular guiding grooves on the hydrodynamic characteristics. The results confirm the relationship between peak pressure, speeds, and eccentricity ratios, as well as the impact of clearances on maximum/minimum pressure. Theoretical analysis coincided with experimental data, verifying the rationality and correctness of the lubrication models.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Kun Yang, Tao Zhang
Summary: Deformation of the stern shaft caused by ship maneuvering can lead to lubrication failure and wear of the stern bearing. The deflection equation of the stern shaft under the action of interface force and propeller load was established using the displacement superposition method, and the fluid-solid coupling model of the stern bearing was established using the averaged Reynolds equation, the Greenwood-Tripp model, and the influence coefficient method. Experimental validation was conducted and the influence of shaft bending deformation on lubrication characteristics was discussed. The results indicate that shaft bending deformation affects lubrication characteristics along the axial and circumferential directions.
Article
Engineering, Mechanical
Zhongliang Xie, Yun Zhang, Jinzhu Zhou, Weidong Zhu
Summary: This paper aims to reveal the micro interface lubrication regimes of water lubricated bearings through computational fluid dynamic analysis. The influences of operating conditions and dimensionless structural parameters on fluid features are explored, and experimental data verifies the correctness of the lubrication model. The research results lay a solid foundation for further optimal design of such bearings.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Mechanical
Guangwu Zhou, Renpan Li, Daxin Liao, Wanyou Yang, Ping Zhong
Summary: In order to meet the urgent requirements of shaftless rim-driven thrusters for low and medium speed, high load capacity, and wear-resistant water-lubricated bearings, this paper conducted research on the lubrication structure design of water-lubricated spiral groove rubber thrust bearings (SGRTBs). A mixed lubrication analysis technique was proposed, considering the effect of surface roughness, and the optimization design of the spiral groove structure parameters was achieved, addressing the mixed lubrication issue of typical spiral surface contact.
TRIBOLOGY INTERNATIONAL
(2023)
Review
Engineering, Mechanical
Zhongliang Xie, Jian Jiao, Kang Yang, Hao Zhang
Summary: This paper provides a detailed summary of water-lubricated bearings in five typical aspects: lubrication regime, fluid-solid interaction (FSI), thermal effect, tribological behaviors, and vibration-noise performances. It extracts and acquires the influencing factors, judgement criteria, and lubrication mechanism of the lubrication regime. The methodology and parameters influencing temperature rise are summarized. The generation mechanism of tribological behaviors and vibration & noise is obtained. The paper systematically combs and summarizes the theories and methods of water-lubricated bearings, pointing out the existing problems and urgent technologies that need to be solved. The findings can serve as a distinct theoretical and methodological reference for further investigation on water-lubricated bearings.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Christoph Baum, Hartmut Hetzler, Simon Schroeders, Tim Leister, Wolfgang Seemann
Summary: A novel physical and mathematical model of foil air bearings was developed with a focus on computational time-efficiency for rotor dynamic investigations. The model, which accounts for nonlinear deformation behavior and linear viscous damping, was validated using published experimental data and reduction technique, showing a decrease in computation time up to a factor of 1000 with a slight loss in accuracy. The bearing model was also coupled with a rigid rotor model to demonstrate its applicability during a run-up and coast-down.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Zhongliang Xie, Weidong Zhu
Summary: The paper investigates the micro asperity contact load ratios and lubrication states of water-lubricated bearings. New coupled models are proposed to consider the micro-scale effects of asperity contact. The study establishes the relevance of load ratio with transition of lubrication regimes under various structural parameters and operating conditions, revealing the mechanism of regimes transition at the micro level. Experimental measurements verify the correctness of the revised model.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Chemistry, Physical
Zhihao Li, Xiaoli Wang, Tie Fu, Yanqiang Hu, Lizhou Li, Zirui Zhao, Liyan Wu, Chenfei Wang, Shuaishuai Zhang
Summary: This study investigates the use of BaTiO3/polyimide (BTO/PI) nanocomposite films and lubricants to improve the tribological and electrification performance of the triboelectric speed sensor (TSS). A nano-film composite lubricated TSS (NFCL-TSS) is constructed and integrated with a bearing. The results show that the NFCL-TSS has lower mass loss, higher electrical output and stability compared to the TSS with pure PI under dry conditions, and can effectively monitor bearing skidding.
Article
Instruments & Instrumentation
Wu Ouyang, Zhenjiang Zhou, Yong Jin, Xinping Yan, Yuanchang Liu
REVIEW OF SCIENTIFIC INSTRUMENTS
(2020)
Article
Engineering, Mechanical
Wu Ouyang, Qilong Yan, Junxin Kuang, Yong Jin, Weicai Peng
Summary: By introducing the squeeze film damper technology, the design of ship water-lubricated stern bearing successfully balances high load-carrying capacity and low natural frequency. Experimental results indicate that WDSB shows significant vibration reduction effect compared to CWSB.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2021)
Article
Engineering, Mechanical
Wu Ouyang, Qichao Cheng, Yong Jin, Qilin Liu, Bin Wang, Lei Wang
Summary: By calculating a three-dimensional mechanical model, a fluid-solid coupling model for water-lubricated journal bearings was proposed, showing the impact of journal bending on lubrication performance distribution and high pressure peaks at both ends of the bearing. As eccentricity increases and Young's modulus of lining decreases, the aggregation phenomenon intensifies.
TRIBOLOGY TRANSACTIONS
(2021)
Article
Engineering, Civil
Hongfen Bai, Bo Yu, Wu Ouyang, Xinping Yan, Jingwei Zhu
Summary: The study introduces a sensorless control algorithm based on high frequency current injection to estimate the rotor position accurately, which improves the reliability of the fault tolerant motor system.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2022)
Article
Chemistry, Analytical
Jinjun Li, Wu Ouyang, Qilin Liu, Zhuo Zhang, Yan Zhang
Summary: In this paper, an experiment on water-lubricated stern bearing (WSB) is conducted, and a bearing film-thickness identification model is established. The distributed lubrication characteristics of WSB under different speeds are systematically analyzed. The results show that the maximum identification error of the model is less than 7%, the lubrication state of the bearing changes dynamically with speed, and the area of each lubrication sub-region varies nonlinearly.
Article
Engineering, Marine
Wu Ouyang, Qilin Liu, Qichao Cheng, Gao Wan, Yong Jin
Summary: In this study, the centralized dynamic characteristics of traditional journal bearings were investigated. It was found that a distributed dynamic characteristic will be generated along the axial direction for journal bearings with a large aspect ratio. A suitable loading method was developed, and a corresponding test-rig was set up. Two excitation methods were proposed. Experimental results showed that the eight-time cross excitation method had a higher signal-to-noise ratio and provided more accurate identification results. The study also revealed that shaft bending is the main factor contributing to the increase in local dynamic characteristic coefficients.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Civil
Bin Wang, Wu Ouyang, Shengtong Wang, Chenxing Sheng, Jinhua Xiao, Zhe Li
Summary: In this study, a novel Magnetic Liquid-double-suspension Elastic-supported Thrust Bearing (MLETB) is designed for the heavy load and low viscosity operation conditions of the marine rim-driven thruster (RDT). The MLETB combines the structural features of the Rubber-supported Water-lubricated Thrust Bearing (RWTB) and Permanent Magnet Bearing (PMB). The experimental results show that the MLETB has better load capacity and dynamic performance, but its stiffness and damping are seriously affected by the specific rubber structure.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Engineering, Marine
Wu Ouyang, Qilin Liu, Jinhua Xiao, Jian Huang, Zhuo Zhang, Lei Wang
Summary: A full-size test rig of water-lubricated stern bearing (WSB) with an elevation adjustment device was constructed and various measurement devices were used to study the lubrication characteristics of the bearing under different conditions. The distribution lubrication characteristic of WSB at the axial direction was observed, and the bearing lubrication region was divided into three sub-regions with different take-off speeds. The negative pressure and hull deformation were found to affect the lubrication characteristics and loads carried by the water film and asperity contact.
Article
Engineering, Multidisciplinary
Fei Hu, Changxiong Ning, Wu Ouyang
Summary: Water-lubricated polymer bearing is crucial for the operation of various equipment. This paper proposes an in-situ measurement method for bearing wear using ultrasound and parameter inversion. The experiment proves the high accuracy of parameter inversion for thickness, density, and attenuation factor, with errors within acceptable ranges.
Article
Engineering, Mechanical
Changxiong Ning, Wu Ouyang, Fei Hu, Xinping Yan, Dongling Xu
Summary: This paper proposes a wear monitoring method based on an improved ultrasonic reflection coefficient amplitude spectrum to overcome the challenges caused by the viscoelasticity, heterogeneity, and acoustic attenuation of polymer materials. The method utilizes an ultrasonic transfer function and a differential evolutionary algorithm to accurately determine the thickness, sound velocity, density, and attenuation coefficients of polymer bearings. Experimental results demonstrate that the method achieves a thickness identification error of approximately 0.5% for different probe contact pressure, roughness, and tilt angle conditions, and a reconfiguration thickness identification error of less than 1% for all water film overlap situations.
Article
Engineering, Mechanical
Qilin Liu, Wu Ouyang, Ruiqing Li, Yong Jin, Tao He
Summary: This paper aims to study the demand of underwater vehicles for water-lubricated stern bearings with low noise, low vibration, high load capacity, and long service life. A series of experiments was conducted to analyze the lubrication and vibration characteristics of three test bearings with different bushing materials and structures. The results indicate that under extreme working conditions, the modified polyurethane bearing shows the best comprehensive performance. Specific pressure and environment temperature significantly influence the bearing performance, while flow rate has limited effect. The research provides important references for the material and structure design and performance testing of water-lubricated stern bearings.
Article
Engineering, Marine
Yong Jin, Ruiqing Li, Wu Ouyang, Zhenglin Liu, Qilin Liu, Qipeng Xiong, Jianhui Zhou
Summary: Under low speed and heavy load operating conditions, the marine water-lubricated bearing (WLB) experiences abnormal friction-induced vibrations and noise in underwater vehicles due to mixed lubrication state. An empirical mode decomposition (EMD) based method was proposed to identify the friction-induced vibration characteristics of WLB and experiments were conducted. The study revealed that specific pressure and lubricant temperature had significant effects on friction-induced vibrations, while cooling water flow had little effect. Analyzing the characteristics of IMF energy, time-domain standard deviation, bias angle, and center of gravity frequency could visualize the trend and critical points of friction-induced vibrations.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Mechanical
Xuanen Kan, Yanjun Lu, Fan Zhang, Weipeng Hu
Summary: A blade disk system is crucial for the energy conversion efficiency of turbomachinery, but differences between blades can result in localized vibration. This study develops an approximate symplectic method to simulate vibration localization in a mistuned bladed disk system and reveals the influences of initial positive pressure, contact angle, and surface roughness on the strength of vibration localization.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Zimeng Liu, Cheng Chang, Haodong Hu, Hui Ma, Kaigang Yuan, Xin Li, Xiaojian Zhao, Zhike Peng
Summary: Considering the calculation efficiency and accuracy of meshing characteristics of gear pair with tooth root crack fault, a parametric model of cracked spur gear is established by simplifying the crack propagation path. The LTCA method is used to calculate the time-varying meshing stiffness and transmission error, and the results are verified by finite element method. The study also proposes a crack area share index to measure the degree of crack fault and determines the application range of simplified crack propagation path.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Rongjian Sun, Conggan Ma, Nic Zhang, Chuyo Kaku, Yu Zhang, Qirui Hou
Summary: This paper proposes a novel forward calculation method (FCM) for calculating anisotropic material parameters (AMPs) of the motor stator assembly, considering structural discontinuities and composite material properties. The method is based on multi-scale theory and decouples the multi-scale equations to describe the equivalence and equivalence preconditions of AMPs of two scale models. The effectiveness of this method is verified by modal experiments.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Hao Zhang, Jiangcen Ke
Summary: This research introduces an intelligent scheduling system framework to optimize the ship lock schedule of the Three Gorges Hub. By analyzing navigational rules, operational characteristics, and existing problems, a mixed-integer nonlinear programming model is formulated with multiple objectives and constraints, and a hybrid intelligent algorithm is constructed for optimization.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Jingjing He, Xizhong Wu, Xuefei Guan
Summary: A sensitivity and reliability enhanced ultrasonic method has been developed in this study to monitor and predict stress loss in pre-stressed multi-layer structures. The method leverages the potential breathing effect of porous cushion materials in the structures to increase the sensitivity of the signal feature to stress loss. Experimental investigations show that the proposed method offers improved accuracy, reliability, and sensitivity to stress change.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Benyamin Hosseiny, Jalal Amini, Hossein Aghababaei
Summary: This paper presents a method for monitoring sub-second or sub-minute displacements using GBSAR signals, which employs spectral estimation to achieve multi-dimensional target detection. It improves the processing of MIMO radar data and enables high-resolution fast displacement monitoring from GBSAR signals.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xianze Li, Hao Su, Ling Xiang, Qingtao Yao, Aijun Hu
Summary: This paper proposes a novel method for bearing fault identification, which can accurately identify faults with few samples under complex working conditions. The method is based on a Transformer meta-learning model, and the final result is determined by the weighted voting of multiple models.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xiaomeng Li, Yi Wang, Guangyao Zhang, Baoping Tang, Yi Qin
Summary: Inspired by chaos fractal theory and slowly varying damage dynamics theory, this paper proposes a new health monitoring indicator for vibration signals of rotating machinery, which can effectively monitor the mechanical condition under both cyclo-stationary and variable operating conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Hao Wang, Songye Zhu
Summary: This paper extends the latching mechanism to vibration control to improve energy dissipation efficiency. An innovative semi-active latched mass damper (LMD) is proposed, and different latching control strategies are tested and evaluated. The latching control can optimize the phase lag between control force and structural response, and provide an innovative solution to improve damper effectiveness and develop adaptive semi-active dampers.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Menghao Ping, Xinyu Jia, Costas Papadimitriou, Xu Han, Chao Jiang, Wang-Ji Yan
Summary: Identification of non-Gaussian processes is a challenging task in engineering problems. This article presents an improved orthogonal series expansion method to convert the identification of non-Gaussian processes into a finite number of non-Gaussian coefficients. The uncertainty of these coefficients is quantified using polynomial chaos expansion. The proposed method is applicable to both stationary and nonstationary non-Gaussian processes and has been validated through simulated data and real-world applications.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Lei Li, Wei Yang, Dongfa Li, Jianxin Han, Wenming Zhang
Summary: The frequency locking phenomenon induced by modal coupling can effectively overcome the dependence of peak frequency on driving strength in nonlinear resonant systems and improve the stability of peak frequency. This study proposes the double frequencies locking phenomenon in a three degrees of freedom (3-DOF) magnetic coupled resonant system driven by piezoelectricity. Experimental and theoretical investigations confirm the occurrence of first frequency locking and the subsequent switching to second frequency locking with the increase of driving force. Furthermore, a mass sensing scheme for double analytes is proposed based on the double frequencies locking phenomenon.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Kai Ma, Jingtao Du, Yang Liu, Ximing Chen
Summary: This study explores the feasibility of using nonlinear energy sinks (NES) as replacements for traditional linear tuned mass dampers (TMD) in practical engineering applications, specifically in diesel engine crankshafts. The results show that NES provides better vibration attenuation for the crankshaft compared to TMD under different operating conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Wentao Xu, Li Cheng, Shuaihao Lei, Lei Yu, Weixuan Jiao
Summary: In this study, a high-precision hydraulic mechanical stand and a vertical mixed-flow pumping station device were used to conduct research on cavitation signals of mixed-flow pumps. By analyzing the water pressure pulsation signal, it was found that the power spectrum density method is more sensitive and capable of extracting characteristics compared to traditional time-frequency domain analysis. This has significant implications for the identification and prevention of cavitation in mixed-flow pump machinery.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xiaodong Chen, Kang Tai, Huifeng Tan, Zhimin Xie
Summary: This paper addresses the issue of parasitic motion in microgripper jaws and its impact on clamping accuracy, and proposes a symmetrically stressed parallelogram mechanism as a solution. Through mechanical modeling and experimental validation, the effectiveness of this method is demonstrated.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Zhifeng Shi, Gang Zhang, Jing Liu, Xinbin Li, Yajun Xu, Changfeng Yan
Summary: This study provides useful guidance for early bearing fault detection and diagnosis by investigating the effects of crack inclination and propagation direction on the vibration characteristics of bearings.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
