Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment最新文献

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Influence of operating conditions in nonlinear vibration of a drill-string 工作条件对钻杆非线性振动的影响

Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment Pub Date : 2024-05-24 DOI: 10.1177/14750902241254144

Simone Faria Almeida, LL Vignoli

{"title":"Influence of operating conditions in nonlinear vibration of a drill-string","authors":"Simone Faria Almeida, LL Vignoli","doi":"10.1177/14750902241254144","DOIUrl":"https://doi.org/10.1177/14750902241254144","url":null,"abstract":"In this work, the vibrational analysis of an oil drill-string is carried out concerning nonlinear and nonsmooth dynamical model with coupled axial-torsional modes. This study aims to investigate the influence of operating conditions to avoid bit-bounce and stick-slip phenomena. A discrete lumped dynamic model with two degrees of freedom is considered. Dry friction and the possibility of loss of contact between the bit and the formation introduce two nonsmooth conditions into the system. Numerical simulations are performed to obtain the dynamic responses and to evaluate critical operating conditions. A parametric analysis is carried out to determine the influence of the weight on the drill bit and the angular velocity of the rotary table on the severity of critical vibrations for different drilling depths. A map is obtained, where normal operation, stick-slip, and bit-bounce responses are defined, allowing a choice of suitable parameters so that the drill-string does not experience critical vibration issues. The results indicate that the safety region, where normal operation is realized, depends on the drilling depth. However, when the angular velocity of the rotary table is equal to 10 rad/s and the weight on the drill bit is greater than 55 kN ensures normal operation for any drilling depth.","PeriodicalId":503502,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"67 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low emission stepped piston engine for marine outboard motor application 用于船用舷外发动机的低排放步进式活塞发动机

Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment Pub Date : 2024-01-12 DOI: 10.1177/14750902231220697

Peter R Hooper

{"title":"Low emission stepped piston engine for marine outboard motor application","authors":"Peter R Hooper","doi":"10.1177/14750902231220697","DOIUrl":"https://doi.org/10.1177/14750902231220697","url":null,"abstract":"Separating the scavenging process from the lubrication methodology in conventional two-stroke engines is an effective method of reducing emissions. Segregation of scavenging by use of stepped pistons is one such method providing significant improvements in engine durability, and reduced lubricant consumption, together with reduced production cost. The study discusses the approaches used together with those applied to conventional engines. This paper focusses on a marine outboard motor application and cross-comparisons with a comparable four-stroke outboard motor are drawn within the study. One-dimensional computational fluid dynamics models of the engine types have allowed performance and emissions simulations. Where possible, data from experimental dynamometer testing is compared with the theoretical models. A reasonable level of correlation in terms of performance has been observed. Two-stroke cycle engines are able to demonstrate reduced oxides of nitrogen emissions when compared with conventional four-stroke engines. Models of the stepped piston engine have confirmed the lower NOx emission evident with operation on the two-stroke cycle.","PeriodicalId":503502,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"29 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139532351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental and numerical study on the shock characteristics of an electric switchboard with wire rope isolators in naval ships 海军舰艇中带有钢丝绳隔离器的配电盘冲击特性的实验和数值研究

Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment Pub Date : 2024-01-09 DOI: 10.1177/14750902231222521

Youngin Park, Min-Su Kang, Myung-Hyun Kim, Jungho Choi, Jeong-Hwan Kim

{"title":"Experimental and numerical study on the shock characteristics of an electric switchboard with wire rope isolators in naval ships","authors":"Youngin Park, Min-Su Kang, Myung-Hyun Kim, Jungho Choi, Jeong-Hwan Kim","doi":"10.1177/14750902231222521","DOIUrl":"https://doi.org/10.1177/14750902231222521","url":null,"abstract":"Naval vessels face significant challenges owing to vibrations and shocks originating from diverse sources. Maintaining high levels of vibration and shock resistance in ship equipment is crucial to prevent damage and ensure proper functionality in demanding environments. This study experimentally and numerically investigates the shock characteristics of an electric switchboard on a naval ship using wire rope isolators (WRIs). Following the MIL-S-901D standard, impact tests were conducted using a test model. A simplified WRI model was constructed based on a previous study using the finite element method. The tests were performed in the vertical and 30° inclined orientations, and the experimental and simulation results were compared. Although an overall agreement was observed between the two, some inconsistencies were noted. These discrepancies were attributed to the inaccurate representation of the WRI. The dynamic stiffness of the WRI derived from the vibration tests conducted in this study may not be suitable for impact tests. Additionally, the modelled WRI in the simulation, as a 1D spring element with different support points, differed from the experimental setup, possibly causing localized effects that influenced the stress distribution. This study emphasizes the importance of refined WRI modelling for accurate shock simulations and offers insights into enhancing the shock resistance of naval ship equipment.","PeriodicalId":503502,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment","volume":"37 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139442641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0