{"title":"Effects of turbulence and bush wear on the transient tribo-dynamic characteristics of water-lubricated bearings","authors":"Ziqi Chen, Ji Wang, Rui Li, Yujun Liu, Pengfa Yu","doi":"10.1177/13506501241233353","DOIUrl":"https://doi.org/10.1177/13506501241233353","url":null,"abstract":"This research proposes a transient mixed elastohydrodynamic model considering turbulence and bush wear, as well as the concept of contact work, to study the transient tribo-dynamic characteristics of water-lubricated bearings. The effects of turbulence, wear depth, and wear deviation angle on transient tribo-dynamic characteristics of water-lubricated bearings are investigated. The findings show that turbulence significantly affects the dynamics of stable conditions and enhances the hydrodynamic effect, but little affects the frictional contact behavior. An appropriate wear depth favors improving the tribo-dynamic characteristics of the water-lubricated bearings, but it deteriorates as the wear depth continuously increases. Negative deviation angles are better for minimizing contact work and enhancing rotor stability. The lubrication and dynamic properties of water-lubricated bearings can be enhanced through a rational approach to wear morphology design. This research is important for the optimal design and diagnosis of water-lubricated bearings wear failures.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140433834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AI techniques for evaluating misaligned journal bearing performance: An approach beyond the Sommerfeld number","authors":"Georgios N Rossopoulos, Christos I. Papadopoulos","doi":"10.1177/13506501241232457","DOIUrl":"https://doi.org/10.1177/13506501241232457","url":null,"abstract":"This paper presents two novel artificial intelligence-based approaches for evaluating the performance of heavily loaded marine journal bearings including shaft misalignment. Traditionally, the Sommerfeld number has been used as a key parameter to evaluate the performance similarity between different bearings. However, this method has limitations, particularly when dealing with complex elastic geometries, heavily loaded journal bearings and shaft misalignment. The first proposed approach leverages neural networks to analyze key bearing performance parameters and provide a more accurate and comprehensive assessment of bearing performance similarity, including additional parameters beyond the Sommerfeld number limitations. The second method utilizes artificial intelligence convolutional networks to assess the bearing similarity based on their simulated pressure profiles under isoviscous and isothermal hydrodynamic lubrication regime. The effectiveness of the proposed methods is demonstrated and compared to the traditional Sommerfeld number method, discussing various potential applications and extensions of this concept.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140438244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Parikh, S. Chokshi, Vijay Chaudhary, Ankit D. Oza, Chander Prakash
{"title":"Development and characterization of eco-friendly extruded green composites using PLA/wood dust fillers","authors":"H. Parikh, S. Chokshi, Vijay Chaudhary, Ankit D. Oza, Chander Prakash","doi":"10.1177/13506501241233628","DOIUrl":"https://doi.org/10.1177/13506501241233628","url":null,"abstract":"Nowadays, there is a rising demand for bio-composite materials driven by the increasing need for sustainable alternatives and a desire to lessen dependence on conventional materials. These bio-composites resent eco-friendly solutions to address these challenges. In line with this, the present study focuses on the bio composite material which developed from polylactic acid (PLA) and wood dust (NF). Wood dust sourced from teak wood plants was employed as fillers. PLA served as the matrix material, supplemented with the plasticizer polyethylene glycol (PEG) to enhance PLA processing. The PLA/NF filament was produced through the extrusion process, and specimens were prepared using 3D printing techniques in accordance with ASTM standards. Various properties including mechanical, physical, thermal stability, and tribological properties were examined. Morphological structures were observed using scanning electron microscopy (SEM). The test results demonstrated improvements in enhanced mechanical robustness and tribological performance of the PLA composite. The tensile strength of the PLA/wood composite was enhanced by 11%. The hardness value of the PLA/wood composite increased by 27% with the addition of wood as filler material. However, the introduction of wood as filler material led to degradation in physical properties. The water absorption test revealed a thickness change of approximately 14% for the PLA wood composite, whereas for pure PLA, it was 9%. Thermal stability tests showed that the temperature resistance of PLA improved to 250 °C with the introduction of wood fillers. Biodegradability tests indicated that PLA wood composite has the potential to address environmental concerns associated with conventional materials.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139958048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Leonardo da Vinci's writings on sliding bearings, lubrication and wear","authors":"Ian M Hutchings","doi":"10.1177/13506501241232036","DOIUrl":"https://doi.org/10.1177/13506501241232036","url":null,"abstract":"This article provides the first comprehensive study of the material relating to sliding bearings, lubrication and wear within the writings of Leonardo da Vinci (1452–1519). While in many instances he was evidently describing contemporary practice, in other cases he demonstrated great innovation and insight. His descriptions of plain journal and pivot bearings and their materials are far richer than those of any other Renaissance engineer. His ability to classify and analyse his observations led him to highly perceptive conclusions about the effect of loading direction on wear rate and the mechanisms of wear in sliding contacts. In deducing the dependence of wear on load and sliding duration, Leonardo's thinking anticipated that of Reye, Preston and Archard by more than 350 years.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140451479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Naser S Sanoussi, M. Hammami, N. Feki, Tarek Belgasam, M. Abbes, Mohamed Haddar
{"title":"Utilizing design of experiments techniques to determine the optimal coefficient of friction in spur gears","authors":"Naser S Sanoussi, M. Hammami, N. Feki, Tarek Belgasam, M. Abbes, Mohamed Haddar","doi":"10.1177/13506501231223073","DOIUrl":"https://doi.org/10.1177/13506501231223073","url":null,"abstract":"The friction occurring between the teeth of gears is a significant contributor to energy loss in gear drives. Factors like the load, speed, and coefficient of friction (µ) play a crucial role in determining the extent of frictional losses in gears. The coefficient of friction (µ) is a complex function influenced by various tribological parameters, including rolling, and sliding velocities, normal load at the tooth contact zone, oil temperature, and contact surface roughness. To analyze the impact of design and operating parameters on the coefficient of friction, a comprehensive statistical parametric approach was employed, combining numerical and statistical methods. The study employed a design of experiments methodology to numerically examine the impact of various tribological factors on the coefficient of friction. This methodology facilitated the identification of primary effects and crucial factors that have a significant impact on the variable µ. The findings derived from the computational models were subsequently compared with the discoveries of pre-existing investigations that includes both experimental and theoretical approaches. The proposed method represents a powerful tool for understanding the relationship and correlation between major tribological factors and the coefficient of friction. By employing this approach, it becomes possible to identify optimized tribological parameters. This information is valuable in improving the design and operation of gear systems, with the aim of reducing energy loss due to friction and enhancing overall efficiency.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140452622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yipan Deng, Yinshui Liu, Hao Pang, Runzhou Xu, Peiling Ke
{"title":"Improving the tribological performance of CFRPTFE at elevated temperature by sliding against Ti-TiCx/DLC film","authors":"Yipan Deng, Yinshui Liu, Hao Pang, Runzhou Xu, Peiling Ke","doi":"10.1177/13506501231209550","DOIUrl":"https://doi.org/10.1177/13506501231209550","url":null,"abstract":"Polytetrafluoroethylene (PTFE) has been widely used in industrial field for sealing parts. However, it is well known that PTFE is always subject to serious wear at high temperature (over 150 °C), which has become the main drawback limiting serve life of important equipment such as compressors. In this paper, a new solution is proposed for improving the wear resistance of carbon fibers-reinforced PTFE (CFRPTFE). Multilayer Ti-TiCx/DLC film is prepared and used as the counterface of CFRPTFE. Friction and wear tests at high temperature (200 °C and 250 °C) are carried out. The uncoated 17-4PH steel disks precisely polished by abrasive papers with different grain sizes are used as the reference counterface (SS80 and SS7000). It is found that by sliding against Ti-TiCx/DLC film, the tribological behaviors of CFRPTFE at high temperature can be improved. The friction coefficient between CFRPTFE and DLC under different test conditions can be kept in stable state. The wear rates of CFRPTFE reduce by 50%–70% compared to SS80, and reduction of 20%–40% can be observed when compared to SS7000. It can be found that graphitization transition at high temperature promotes the transfer layer formation and contributes to lower friction and lower wear compared to traditional processed counterface at high temperature. These significant improvements can prolong the lifetime of CFRPTFE moving parts used in high-temperature and heavy-load applications. Finally, engineering verification of the proposed friction pair is carried out in miniature oil-free high-pressure compressor.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139853155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yipan Deng, Yinshui Liu, Hao Pang, Runzhou Xu, Peiling Ke
{"title":"Improving the tribological performance of CFRPTFE at elevated temperature by sliding against Ti-TiCx/DLC film","authors":"Yipan Deng, Yinshui Liu, Hao Pang, Runzhou Xu, Peiling Ke","doi":"10.1177/13506501231209550","DOIUrl":"https://doi.org/10.1177/13506501231209550","url":null,"abstract":"Polytetrafluoroethylene (PTFE) has been widely used in industrial field for sealing parts. However, it is well known that PTFE is always subject to serious wear at high temperature (over 150 °C), which has become the main drawback limiting serve life of important equipment such as compressors. In this paper, a new solution is proposed for improving the wear resistance of carbon fibers-reinforced PTFE (CFRPTFE). Multilayer Ti-TiCx/DLC film is prepared and used as the counterface of CFRPTFE. Friction and wear tests at high temperature (200 °C and 250 °C) are carried out. The uncoated 17-4PH steel disks precisely polished by abrasive papers with different grain sizes are used as the reference counterface (SS80 and SS7000). It is found that by sliding against Ti-TiCx/DLC film, the tribological behaviors of CFRPTFE at high temperature can be improved. The friction coefficient between CFRPTFE and DLC under different test conditions can be kept in stable state. The wear rates of CFRPTFE reduce by 50%–70% compared to SS80, and reduction of 20%–40% can be observed when compared to SS7000. It can be found that graphitization transition at high temperature promotes the transfer layer formation and contributes to lower friction and lower wear compared to traditional processed counterface at high temperature. These significant improvements can prolong the lifetime of CFRPTFE moving parts used in high-temperature and heavy-load applications. Finally, engineering verification of the proposed friction pair is carried out in miniature oil-free high-pressure compressor.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139793402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-objective optimization of surface texture shape in fluid mechanical face seals using mass-conserving cavitation boundary condition","authors":"Yulong Li, Yongyong He, Jianbin Luo","doi":"10.1177/13506501241228890","DOIUrl":"https://doi.org/10.1177/13506501241228890","url":null,"abstract":"Surface texture shape significantly influences the tribological and sealing properties of fluid mechanical face seals. Considering that it is a contradiction to simultaneously improve load capacity and reduce leakage, a numerical multi-objective optimization model is proposed herein to improve the load-carrying capacity while reducing the volume leakage rate via texture shape optimization. The mass-conserving cavitating boundary condition and the non-dominated sorting genetic algorithm II are employed for the optimization. The numerical results indicate that the optimal texture shape is spiral-like under the lowest volume leakage rate, which becomes an asymmetric flat-front chevron with increasing load-carrying capacity and volume leakage rate. The optimal shape outperforms four regular shapes (all obtained by multi-objective optimization) at different rotation speeds and sealing pressures. The cavitation within the optimal shape ensures zero leakage in fluid face seals. The comprehensive performance of the texture shape obtained by multi-objective optimization is superior to that obtained by single-objective optimization.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139866903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-objective optimization of surface texture shape in fluid mechanical face seals using mass-conserving cavitation boundary condition","authors":"Yulong Li, Yongyong He, Jianbin Luo","doi":"10.1177/13506501241228890","DOIUrl":"https://doi.org/10.1177/13506501241228890","url":null,"abstract":"Surface texture shape significantly influences the tribological and sealing properties of fluid mechanical face seals. Considering that it is a contradiction to simultaneously improve load capacity and reduce leakage, a numerical multi-objective optimization model is proposed herein to improve the load-carrying capacity while reducing the volume leakage rate via texture shape optimization. The mass-conserving cavitating boundary condition and the non-dominated sorting genetic algorithm II are employed for the optimization. The numerical results indicate that the optimal texture shape is spiral-like under the lowest volume leakage rate, which becomes an asymmetric flat-front chevron with increasing load-carrying capacity and volume leakage rate. The optimal shape outperforms four regular shapes (all obtained by multi-objective optimization) at different rotation speeds and sealing pressures. The cavitation within the optimal shape ensures zero leakage in fluid face seals. The comprehensive performance of the texture shape obtained by multi-objective optimization is superior to that obtained by single-objective optimization.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139806620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical simulation of the dynamic fluid–solid coupling in journal bearing with the effect of surface topography in consideration","authors":"Di Zhang, Haijun Wei, C. Gu","doi":"10.1177/13506501241228645","DOIUrl":"https://doi.org/10.1177/13506501241228645","url":null,"abstract":"In the case of the journal-bearing system under a mixed or boundary lubrication regime, the deformation of the bearing, the flow of the lubricating medium, and the contact of the asperities should be taken into account. The lubrication problem at the journal-shaft interface is a complicated fluid–solid coupling problem. In this study, a new approach is proposed to analyze the dynamic fluid–solid coupling problem of journal bearings. The dynamic fluid–solid coupling problem is solved by the presented non-linear hybrid conjugate gradient method, which is based on the principle of pressure balance in the lubrication zone. One transient mixed lubrication model was developed to analyze the journal-bearing performance by considering the effects of skewness and kurtosis and the mass-conserving cavitation. According to the simulated results from the journal-bearing systems under the start-up condition, it can be found that the bearing performance is sensitive to the value of skewness or kurtosis and the degree of misalignment. Within a certain range, these cases with more negative skewness or lower kurtosis are conducive to decreasing friction loss and lift-off time. The developed model can be effectively used to track the performance of journal bearings.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140478333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}