Articles de revues : « Ship noise and vibration »

1

Ojak, W. « Vibrations and Waterborne Noise on Fishery Vessels ». Journal of Ship Research 32, n^o 02 (1 juin 1988) : 112–33. http://dx.doi.org/10.5957/jsr.1988.32.2.112.

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The Food and Agricultural Organization of the United Nations granted a fellowship to the author to study, at several European ship research institutes, the problem of noise generation and propagation on fishery vessels. He later took part in the design of the fishery research vessel Prof. Siedlecki, which included the implementation of a series of antivibration and antinoise precautions. This paper compares vibration and noise levels on two fishery research vessels—the conventional RV G.O.Sars and RV Prof. Siedlecki. The paper is divided into two parts. In the first part, mechanical vibrations of the elastically supported propeller are dealt with and conditions for minimum vibration response are determined. In the second part, structural vibrations in the ships and noise propagation from the ships to the water are described. The paper concludes with data on structural vibrations and waterborne noise propagation. This paper, and the paper published in the June 1984 issue of JOURNAL OF SHIP RESEARCH [1],2 completes the author's approach to propeller vibrations.

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Zou, Chun-Ping, Duan-Shi Chen et Hong-Xing Hua. « Investigation of Ship Structural Vibration and Underwater Radiation Noise ». Journal of Ship Research 47, n^o 04 (1 décembre 2003) : 275–89. http://dx.doi.org/10.5957/jsr.2003.47.4.275.

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Underwater radiation noise is a very important factor for most ships, such as fishing boats, warships, and so forth. The magnitude of its energy depends on the vibration of the hull in contact with water. The vibration of the hull caused by the power plant, while the vessel is cruising, is the dominant source of underwater radiation noise, which is the subject of our investigation. In this paper, the coupled finite element/boundary element method is used to investigate ship structural vibration and underwater radiation noise. The finite element method (FEM) is employed to analyze modes and vibration responses of an entire ship for different kinds of excitations in consideration of fluid-structure interaction. The boundary element method (BEM) is used to analyze the underwater radiation noise. A FEM model is first constructed by using 30 geometric parameters and five kinds of finite elements. Then, the reduced matrix method is used to eliminate the local modes in order to obtain the overall bending and torsional modes of the ship. Last, vibration displacements of the hull are treated as the velocity boundary condition of BEM to calculate underwater radiation noise. Numerical results show thatthe calculated sound-pressure levels of underwater radiation noise are in a good agreement with experimentally measured results;although the vibration isolator is used, the propulsion diesel engine is the dominant source of the underwater radiation noise among all machines in the engine room and the maximum sound-pressure levels increase as the sailing speed of the ship increases;the underwater radiation noise of the ship with gearbox excitation is greater than that of the ship with diesel generator set excitation, which should be noticed by the ship designers during the design stage.

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Liu, Hongmin, Xincheng Lin, Zhihao Gong et Jieyuan Shi. « Combined Annoyance Assessment of Ship Structural Vibration and Ambient Noise ». Buildings 13, n^o 2 (28 janvier 2023) : 363. http://dx.doi.org/10.3390/buildings13020363.

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Background: Noise and vibration are environmental pollutants that endanger people’s productivity and sleep quality in ships, but the coupled effect in ship cabins has not been studied. This study aimed to assess the coupled effect of noise and vibration in ship cabins and propose a comfortable range of noise and vibration. Methods: Three different accommodation cabins were chosen to measure noise and vibration levels and investigate their satisfaction. A revised model combining exponential membership functions was proposed to reveal the relationship between noise and vibration level and its response. The annoyance rate from greater to lesser was classified as A, B, C, D, and E. Results: All measurement levels were satisfied with the acceptance ranges of standards. While subjects felt high annoyance in the crew lounge, subjects in passenger and dining cabins felt slightly annoyed. Conclusions: By combining measurements and subjective investigations, the prediction performance of the revised annoyance model was verified. The noise level reached 57.5 dB(A), and the acoustic condition had a greater impact on subjective feelings than the vibration level. For grade E demands, the vibration level should be lower than 0.095 m/s2, and the noise level should be less than 54 dB(A).

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Fang, Yuan Yuan, Guo Hong Zhang, Ya Fan Li et Peng Zhe Qi. « Design of Vibration Isolation Device for Ship Power Equipment and Investigation on its Dynamic Properties ». Applied Mechanics and Materials 496-500 (janvier 2014) : 1129–33. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.1129.

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Mechanical noise caused by power equipment vibration is the main source of underwater radiated noise of the ship, and vibration isolation and noise reduction of ship equipment has been widely concerned. Therefore,a vibration isolation system designed for four sets of auxiliary engine of ship cabin was investigated in the paper, aimed to further reveal the influence of various parameters including floating raft shell thickness, excitation source, and different ship hull and installation platform thickness on the vibration level difference of system. The results obtained from numerical analysis using MSC software and experiment indicate that one-dimensional spring element simplified can properly simulate the actual rubber vibration isolator on low frequency bands, and increasing thickness of flat, hull and platform can improve the effect of vibration isolation obviously.

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Pavan Kumar, GVV, V. V. S. Prasad et B. H. Nagesh. « Measurement of small vessel machinery vibration induced acoustic signature levels ». Journal of Naval Architecture and Marine Engineering 16, n^o 2 (26 décembre 2019) : 87–98. http://dx.doi.org/10.3329/jname.v16i2.42030.

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Ship vibrations, airborne and underwater noise levels have always been a challenging topic from a performance point of view in ship design, building and operation. The measurement shall help in monitoring the self-noise and the technical state of their machinery mechanism. The vibration levels on the main engine and auxiliary Genset foundation, airborne noise levels of the engine room and underwater self-noise levels of a small mechanized fishing trawler was measured at the jetty in idling condition. The vibration levels on the foundation measured the average value of 0.207 mm/s for the main engine and 1.36 mm/s for auxiliary Genset. The airborne noise levels measured 99 dB (A) in the engine room. The peak underwater sound pressure levels measured 162 dB re 1µPa. The response spectra indicate the peak vibration and noise levels in the lower frequency region <1.2 kHz. The machinery excitation forces transferred to the hull surface as pressure fluctuations which generated the airborne and underwater noise levels. Though the measurement limited to jetty conditions, detailed analysis can be useful for detection, classification, and tracking of small vessels.

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Vracar, Miodrag, et Nenad Kovacevic. « Vibration of the vessel and bispectrum of hydroacoustic noise ». Facta universitatis - series : Physics, Chemistry and Technology 7, n^o 1 (2009) : 45–60. http://dx.doi.org/10.2298/fupct0901045v.

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The origin of vessels vibrations is dominantly determined by vessels propulsion system, auxiliary systems, pumps, breaking of the waves at the ship hull, etc. All of these systems contribute to the appearance of the underwater sound in water environment. As a source of underwater sound, vessels has the characteristic of directivity. Vibration of the vessel's structure is analyzed using spectra, but hydroacoustic signals are analyzed using spectra and higher order spectral analysis - bispectra. The measuring of the radiated hydroacoustic noise was done simultaneously with multi channel measurements of the vessels vibrations at few characteristics positions of the vessel.

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Kozaczka, Eugeniusz, Jacek Domagalski et Ignacy Gloza. « Investigation of the underwater noise produced by ships by means of intensity method ». Polish Maritime Research 17, n^o 3 (1 janvier 2010) : 26–36. http://dx.doi.org/10.2478/v10012-010-0025-0.

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Investigation of the underwater noise produced by ships by means of intensity method This paper presents results of research on spectral structure of underwater noise acoustic field radiated into water by selected ships moving in shallow waters. Underwater acoustic field of ships in motion is associated with acoustic activity of ship mechanisms and equipment under work. Vibration energy radiated by the mechanisms and devices is transmitted by ship structural elements to surrounding water where it is propagated in the form of acoustic waves of a wide frequency band. In this paper are presented results of the research on propagation of energy of acoustic waves in the near fiel, obtained from acoustic pressure measurements by means of two sensors located close to each other.

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Zhou, Zhenwei, et Jiaming Wu. « Low to Middle Vibro-Acoustic Noise Prediction in Ship Cabin by Using Plate-Cavity Coupling Model ». Polish Maritime Research 25, s2 (1 août 2018) : 149–57. http://dx.doi.org/10.2478/pomr-2018-0086.

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Abstract A plate-cavity coupling method based on modal expansion technique in the closed sound cavity was introduced, aiming at ship cabin structural noise. Using this method, a coupled equation was established. The structural vibration acceleration of the target cabin was extracted from a ship vibration response calculation, applied to the model. Then the target cabin noise value was obtained through numerical calculation. The effectiveness and reliability of the method were validated through experiments. The coupled model predicts noise in the cabin does not require fluid finite element model of the cabin air, thus greatly reducing the calculation time compared with the pure finite element method. It was shown that the method is suitable for the calculation of noise in a single ship cabin; the method has a high calculation efficiency. Furthermore, the calculated result is a continuum. On the one hand, it can be conveniently converted to an octave or 1/3 octave according to the specification. On the other hand, the form of the continuum also provides a corresponding response to the subsequent vibration and noise control.

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Layuk, Semuel, Tri Martiana, Getruida Banon H. Alow, Dismo Katiandagho, Cherlis Pomalango, Raden Khariyatul Afiyah et Siti Nur Hasina. « Physical environment and work fatigue among ship engine room crew ». International journal of health sciences 6, n^o 3 (5 octobre 2022) : 1556–64. http://dx.doi.org/10.53730/ijhs.v6n3.13248.

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The physical environment of a ship is often found to be below the government’s standard, which affects employees’ health and causes work fatigue. The present study aimed to identify the physical environment and work fatigue in the ship engine room at Manado Port by applying a cross-sectional analytical approach. The study population was forty-one engine room crew of seven ships with Manado-Talaud Archipelago routes with 7-16 hours trip. The research instrument includes a hygrometer, sound level meter, vibration meter, and work fatigue questionnaire (KAUP2). The data were analyzed descriptively and by performing a correlation test. The study found that the ships’ temperature, noise, and vibration exceeded the stipulated threshold limit value. The relationship between the physical environment and work fatigue was also noticed.

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Olunloyo, Vincent O. S., et Charles A. Osheku. « On Vibration and Noise Dissipation in Ship and FPSO Structures with Smart Systems ». ISRN Mechanical Engineering 2012 (7 août 2012) : 1–19. http://dx.doi.org/10.5402/2012/127238.

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Ships and floating structure production systems are widely deployed for deep and ultradeep waters operation. Active vibration reduction and noise control in such structures can significantly improve their hydrodynamic performance and stability during navigation, exploration, and exploitation activities. One way to minimise or reduce the transmission of vibration in these moving offshore structures is to exploit the mechanism of interfacial slip in press fit joints or layered structural laminates in their internal hull configurations to dissipate vibration energy. In this paper, slip damping with heterogeneous sandwich composite viscoelastic beam-plate smart systems as a model for dissipation of vibration and active noise control mechanism in ship and floating structures is investigated. For this problem, a boundary value partial differential equation is formulated for the case of linear and nonlinear hydrodynamic wave loadings. In particular, the effect of pressure distribution variation at the interface of the layered smart system on the energy dissipation, logarithmic damping decrement, and spatial transfer function is analyzed and presented for design application and selection of appropriate stabilizers.

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Ionov, A. V., L. E. Buvailo, M. V. Volkova et A. P. Starostin. « Elastomer materials in ship vibration and noise protection means ». Russian Journal of General Chemistry 80, n^o 10 (octobre 2010) : 2122–33. http://dx.doi.org/10.1134/s1070363210100415.

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姜, 仁威. « Comparative Study of Ship Vibration and Noise Reduction Performance ». Open Journal of Acoustics and Vibration 08, n^o 01 (2020) : 9–16. http://dx.doi.org/10.12677/ojav.2020.81002.

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Xu, Jun Chen, Ming Hong et Hong Yu Cui. « The Contrast Experimental Study on Operational Modal Analysis of Ship Structural Model ». Applied Mechanics and Materials 226-228 (novembre 2012) : 241–46. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.241.

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A ship is a large and multifunctional marine structure operating on the sea. In practice, the environmental noise on a ship has many complicated components and they influence the vibration of the ship structure. Besides the stochastic excitations such as waves and winds, there are also propeller- and host-induced harmonic excitations. In this paper, NExT/ERA algorithm program and a ship model have been made to realize the modal parameters identification of ship structure in the presence of both white noise and harmonic excitations. Moreover, whether the signal filtering technology has a great effect on the results of modal analysis is discussed. In order to study and analyze the influence of the harmonic excitations, experiments under different signal-to-noise ratio (SNR) conditions have been carried out. This has a guiding significance to the engineering practice.

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Дроконов, Алексей, Aleksey Drokonov, Алексей Дроконов et Aleksey Drokonov. « GENERATION AND METHODS FOR VIBRO-ACOUSTIC ACTIVITY DECREASE IN GASCOMPRESSOR UNITS WITH GAS TURBINE DRIVE ». Bulletin of Bryansk state technical university 2017, n^o 1 (31 mars 2017) : 68–71. http://dx.doi.org/10.12737/24894.

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Block-modular gas compressor units (GCU) of a container type with an aircraft and ship gasturbine drive – a power source of vibration and noise pollution of environment. Their basic inner sources – gas turbine engine and a centrifugal compressor. Besides, to power noise sources in the structure of GCU belong multiplier, an air cleaner of the air inlet system, an exhaust shaft, section walls of an engine and a compressor. A gas turbine engine and a compressor define mainly a distant sound field and the rest of noise sources – near-in one. A complex modernization of such plants may be carried out on the basis of the investigations of the level of vibrations and noise of all elements of such units. With this purpose there were carried out inves-tigations of vibro-acoustic characteristics of GCU of GCU-16MG type with the capacity of 16 MW where as a drive of the centrifugal compressor of 370-18-1 NZL type serves a ship convertible engine of DG-90 type produced by “Zarya” Co. Noise sources and vibrations of blade machines are studied, their vibro-acoustic characteristics are analyzed and methods for the decrease of vibro-acoustic activities of GCUs of such a type are offered.

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Shuri, Hideyuki. « Measurements of Vibration and Acoustic Data for Ship Noise Prediction ». Journal of The Japan Institute of Marine Engineering 51, n^o 4 (2016) : 479–86. http://dx.doi.org/10.5988/jime.51.479.

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Du, Taili, Xusheng Zuo, Fangyang Dong, Shunqi Li, Anaeli Elibariki Mtui, Yongjiu Zou, Peng Zhang et al. « A Self-Powered and Highly Accurate Vibration Sensor Based on Bouncing-Ball Triboelectric Nanogenerator for Intelligent Ship Machinery Monitoring ». Micromachines 12, n^o 2 (21 février 2021) : 218. http://dx.doi.org/10.3390/mi12020218.

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With the development of intelligent ship, types of advanced sensors are in great demand for monitoring the work conditions of ship machinery. In the present work, a self-powered and highly accurate vibration sensor based on bouncing-ball triboelectric nanogenerator (BB-TENG) is proposed and investigated. The BB-TENG sensor consists of two copper electrode layers and one 3D-printed frame filled with polytetrafluoroethylene (PTFE) balls. When the sensor is installed on a vibration exciter, the PTFE balls will continuously bounce between the two electrodes, generating a periodically fluctuating electrical signals whose frequency can be easily measured through fast Fourier transform. Experiments have demonstrated that the BB-TENG sensor has a high signal-to-noise ratio of 34.5 dB with mean error less than 0.05% at the vibration frequency of 10 Hz to 50 Hz which covers the most vibration range of the machinery on ship. In addition, the BB-TENG can power 30 LEDs and a temperature sensor by converting vibration energy into electricity. Therefore, the BB-TENG sensor can be utilized as a self-powered and highly accurate vibration sensor for condition monitoring of intelligent ship machinery.

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Lei, Junsong, Ruiping Zhou, Hao Chen, Guobing Huang, Yakun Gao et Qingcao Yang. « Effects of Ship Propulsion Shafting Alignment on Whirling Vibration and Bearing Temperature Response ». Mathematical Problems in Engineering 2021 (27 septembre 2021) : 1–10. http://dx.doi.org/10.1155/2021/8353844.

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Ship’s propulsion shafting is one of the main sources of ship vibration and noise. The shafting, whirling vibrations, and alignment are important factors that affect the comfort, stability, and reliability during a ship’s navigation. However, the mechanism of the interacting of the both factors is not fully revealed. In this paper, the effect of shafting alignment on whirling vibration and the bearing temperature response is studied by experiment. The test scheme is designed reasonably according to the theoretical analysis. The results show that the horizontal component of the shafting whirling vibration can be effectively reduced by adjusting the shafting alignment state while the vertical component is not. The shafting axis balancing position (SABP) slightly moves upward in high speed, which should be considered in the dynamic alignment design of the shafting, especially for the high-speed shafting. Little ABSB (the angle between the shafting centre line and the No. 1 bearing centre line) is beneficial to the stable operation of shafting, while appropriately increasing the ABSB and bearing load is beneficial to reducing the shafting whirling vibration. By balancing the relationship between bearing load and ABSB, the performance of whirling vibration and bearing temperature response can be optimized.

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Zou, Tongda, Yuhang Tang, Xuhong Miao, Yuan Du, Fuxin Jia et Yanhe Shan. « Effect of excitation type on vibration characteristics of typical ship grillage structure ». REVIEWS ON ADVANCED MATERIALS SCIENCE 61, n^o 1 (1 janvier 2022) : 539–51. http://dx.doi.org/10.1515/rams-2022-0053.

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Abstract Aiming at the present situation that the effect of excitation type on typical ship grillage structure vibration is not fully revealed, different excitations are applied on typical ship grillage structure to study the effect of different excitation. Finite element method (FEM) is introduced to solve grillage vibration and sound radiation, and a test model is used to verify the effectiveness of the simulation method by comparing test results and simulation results. Mean square vibration velocity and acoustic power are compared to explore the effect of excitation type on grillage vibration. The research shows that the simulation method (FEM) is effective in grillage vibration and sound radiation; the peak frequency of acoustic power and mean square velocity of grillage structure under different excitation are basically the same; uniform distribution excitation is a better way to reduce structure vibration and noise.

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Zhao, Dagang, Yang Zhang, Qian He, Cong Sun et Mingqi Bi. « Hydrodynamic and Flow Field Characteristics of Water Jet Propulsion under Mooring Conditions ». Journal of Marine Science and Engineering 10, n^o 7 (12 juillet 2022) : 953. http://dx.doi.org/10.3390/jmse10070953.

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The acceleration characteristics of a water jet-propelled ship during startup are related to its performance under mooring conditions. Water jet propulsion cavitation during startup increases the vibration and noise of the whole ship. Therefore, accurately predicting and analyzing the performance, hydrodynamics and flow field characteristics of water jet-propelled ships under mooring conditions can help elucidate the startup characteristics of the ships and optimize their acceleration strategies. In this study, the hydrodynamic and flow field characteristics of water jet propulsion and water jet propulsion ships under mooring conditions were studied using three-dimensional numerical modeling. First, the hydrodynamic performance of the water jet propeller was analyzed, and the relevant flow field law was derived. Then, the hydrodynamic performance, internal and external flow field characteristics, pulsation pressure and flow rate at the nozzle, and pulsation pressure at the monitoring points around the impeller of the water jet propulsion ship model were analyzed under mooring conditions. We obtained the open-water law for the water jet propeller and the hydrodynamic force and flow field law for a two-pump water jet propulsion ship. The ship model developed in this study provides a good theoretical foundation for further research on water jet propulsion.

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Xiao, Neng Qi, Ri Ping Zhou et Xi Chen Lin. « Research on Marine Electric Propulsion Shafting under Electromechanical Coupling Condition ». Applied Mechanics and Materials 607 (juillet 2014) : 477–82. http://dx.doi.org/10.4028/www.scientific.net/amm.607.477.

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Through the establishment of motor electromechanical coupling vibration model, torsional vibration characteristics of motor is analyzed in starting process. With 1000T lubricating oil ship electric propulsion shafting as the object of study, the free vibration and the forced vibration characteristics are analyzed. In two cases of considering the electromagnetic excitation torque and without considering the electromagnetic excitation torque, the responded vibration of electric propulsion shafting is calculated. The low noise design of the motor and propulsion shafting provides a theoretical basis.

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Wang, Xin, Jin Bo Fu et Xun Min Yin. « Study on Design and Simulation of the Vibration-Reduction of the Damp Structure for the Gearbox ». Applied Mechanics and Materials 86 (août 2011) : 139–42. http://dx.doi.org/10.4028/www.scientific.net/amm.86.139.

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The study on design and simulation of reduce vibration are carried out of the damp structure for the simulative experimental gear case to reduce vibration and noise of the ship gearbox. Multiple projects are designed for the gear case of the damp structure on the basis of the structure characteristic of the gearbox. The finite element analyze computation is carried out of box of gear case under the different project of the damp and the different damp material. The fine damp material and the optimization structure parameters of damp will be ascertained by the analysis of mode and frequency response. The contrastive analysis of vibration and noise is carried out for the box of fore-and-aft treat of damp structure. The analytical result indicates that the vibration and noise of gearbox will be reduced observably when the project of damp is adopted.

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Bregant, Luigi, Flavia D'Agostin et Martina Lorenzino. « Are on board comfort classes noise and vibration levels really suitable ? » INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, n^o 5 (1 août 2021) : 1206–14. http://dx.doi.org/10.3397/in-2021-1777.

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In shipbuilding industry, comfort is a relevant issue both for crew members and passengers. A comfortable environment enables crew members to perform accurately their tasks and it is an effective factor contributing to the satisfaction of passengers. Noise and vibration, as environmental parameters, play an important role in subjects' comfort. Naval Classification Societies established series of noise/vibration comfort level criteria, which, however, did not take into account some aspects: 1) noise/vibration recordings are carried out during time periods shorter than the exposure time of passengers; 2) the subjective mood is not investigated. In the present study, we studied comfort perception by measuring heart rate variability and mood. We exposed participants to four levels of acoustic noise [from 45 to 55 dB(A)] and three levels of vibration (1.5, 1.8, 2 mm/s) inside a full-scale mock-up of a cruise ship cabin. We found that the increase of noise/vibration intensity determines an increase of heart rate variability and negative mood. However, changes in comfort responses did not occur for the noise/vibration comfort thresholds identified by the Classification Societies. Our results evidence the importance to include psychophysiological measure of comfort when defining comfort criteria on board.

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Zhou, Jun Wei, Lin He, Rong Wu Xu et Li Lin Cui. « The Transmissibility Function Application in Ship Mechanical Noise Estimation ». Applied Mechanics and Materials 431 (octobre 2013) : 75–81. http://dx.doi.org/10.4028/www.scientific.net/amm.431.75.

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The traditional response estimation model is based on force-response relationship. According to the transmissibility concept in linear time invariant system, a new response estimation method-transmissibility function (TF) method is provided based on response-response relationship. First, the principle of the method is interpreted in mathematic formula and the restriction condition is presented. Then, an engineering technique called operational conditions combination is presented for calculating the transmissibility function (TF) of vibration responses, and the guideline on how to devise the scheme of working conditions is discussed. Finally, the performance of the developed transmissibility function method is validated by a cylindrical double-shell exciting experiment.

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Guo, Jun, Mei-ting Wang, You-wei Kang, Yin Zhang et Chen-xu Gu. « Prediction of Ship Cabin Noise Based on RBF Neural Network ». Mathematical Problems in Engineering 2019 (14 avril 2019) : 1–21. http://dx.doi.org/10.1155/2019/2781437.

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Prediction of cabin noise for new types of ships and offshore platforms, based on measurement or simulation databases, is a common problem that needs a solution at the beginning of the design process. In this paper, we explore the use of a radial basis function (RBF) neural network to study this problem. Within the framework of the RBF network, we implement and compare several algorithms to devise a fast and precise cabin noise prediction model. We select a combination of algorithms after training the RBF with noise measurement samples. The results show that the RBF neural network trained using the DE algorithm has better prediction accuracy, generalization, and robustness than the others. Our work provides a new method for preliminary noise assessment during the schematic design phase and enables rapid analysis of vibration and noise control schemes for ships and offshore platforms.

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Lee, Jen-Chieh, et Jish-Chson Chen. « Active Structural Acoustic Control for Rectangular Plate with a Line Moment Excitation ». Journal of Mechanics 14, n^o 2 (juin 1998) : 75–82. http://dx.doi.org/10.1017/s1727719100000095.

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AbstractActive control of noise radiation from vibrating plate excited by a harmonic line moment is analytically investigated. This study model of simple supported rectangular plate with a line moment excitation is used to simulate the vibration of ship hull or fuselage from the flutter of ship deck or aircraft wing respectively. The control is achieved by various configurations of piezoelectric actuators. The strategy of radiated power minimization is used to obtain the optimal control input unit voltage. The numerical results show that the significant attenuation of noise radiated power for volumetric modes in the low frequency range can be achieved with one control actuator located at the center of plate, irrespective of whether the excitation is on or off resonance. The efficiency of the active control is dependent on the location of the line moment and the actuators. It is also shown that the modal suppression and modal restructuring are two physical mechanisms of radiated power attenuation.

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Yufeng, Gong, Peng Weicai, Zhang Junjie et Liu Zhizhong. « Research on the Impediment to Vibration Wave Propagation of Pipe from a vibration isolation mass ». MATEC Web of Conferences 288 (2019) : 01002. http://dx.doi.org/10.1051/matecconf/201928801002.

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In order to control the pipe vibration, the performance of flexible connection with vibration isolation mass in impeding vibration wave propagation is studied. Based on the principle of impedance mismatching and numerical analysis method, the influences of vibration isolation mass and rotational inertia on the vibration wave propagation in pipe were discussed. The results show that the isolation mass is good at reducing the vibration of wave transmission in intermediate and high frequency domain. Meanwhile, The larger rotational inertia of the isolation mass, the better the damping effect. A useful reference was provided for the application of flexible connection to the vibration isolation and noise reduction of ship pipe.

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Gao, Shengyao, Zhou Tao, Yuhui Li et Fuzhen Pang. « Application research of acoustic black hole in floating raft vibration isolation system ». REVIEWS ON ADVANCED MATERIALS SCIENCE 61, n^o 1 (1 janvier 2022) : 888–900. http://dx.doi.org/10.1515/rams-2022-0235.

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Abstract Acoustic black holes have good application prospects in the field of vibration and noise reduction. Based on engineering practice, this study proposes a systematic process method for the application of acoustic black hole structure in raft structure, which provides new ideas and references for improving the vibration isolation performance of floating raft system and reducing the level of ship vibration and noise. The influence law of each parameter on structural vibration and the recommended value range of each parameter are given, which provides support for the systematic method and process of the application of acoustic black holes in the raft structure. Then, the acoustic black hole process is applied to a floating raft system. According to the characteristics of the raft structure, an application scheme of the acoustic black hole in the raft structure is formed, and the vibration level drop of the floating raft vibration isolation system before and after the acoustic black hole is embedded, calculated, and analyzed. The changes further improve the vibration reduction and isolation performance of the raft system and effectively reduced the mechanical noise level of the ship’s cabin.

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Bahtiarian, Michael. « Ferry M/V Kramer noise mitigation ». INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, n^o 4 (1 août 2021) : 2138–44. http://dx.doi.org/10.3397/in-2021-2060.

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The Motor Vessel (M/V) Edward V. Kramer is an aluminum vessel that operates as a small passenger ferry, which is owned and operated by the Department of Homeland Security (DHS) and used to transport DHS personnel and materials to Plum Island, NY. It was placed in service in 2018 and right from the start the sound levels inside the Main Deck compartment were found to be excessive. The original vessel specification included a noise limit of 75 dBA in the Main Deck Passenger Lounge and measured levels were as high as 87 dBA. A ship survey of sound and vibration was performed. Noise predictions to determine the controlling sound paths was also performed based on engine sound and vibration source levels. Recommendations for mitigation were presented and carried out by another shipyard. Mitigation included vibration isolation of the main engines and sound attenuation improvements to the Main Deck Passenger Lounge. After completion of the modifications, another survey was performed in 2021 and results show a reduction by as much as 11 dB in the Main Deck Passenger lounge. Noise estimation methods and details on the noise control treatments are given in the paper.

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Yan, Li Qi, et Hui Jun Ge. « Study on the Combustion Noise Characteristic of Low Speed Diesel Engine ». Advanced Materials Research 945-949 (juin 2014) : 750–53. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.750.

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In recent years, the Low speed two stroke diesel engines are widely used as the main power device of big ship for its so many advantages such as the high power, better economical efficiency and good maintenance. However, the problem of diesel strong vibration and noise becomes a more and more serious at the same time. Because of the Construction Features of marine two-stroke low-speed diesel engine, the structure has to be suffered different kind of forces when it runs. In considering the source of vibration, the whole noise can be divided into combustion noise、machinery noise and aerodynamic noise. The combustion noise caused by cylinder pressure is the most important part of diesel noise. In this paper, the cylinder pressure curves are tested. The internal combustion engine dynamics and the equivalent node load are used in the calculation procedure to achieve the real condition simulation. The loading program is made to simulate the change of cylinder pressure and the move of piston. The transient response of the diesel engine is calculated. The characteristics of diesel caused by cylinder pressure are analyzed.The response analysis can be used to the vibration control.

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Javier, Rodrigo F., Ramis Jaime, Poveda Pedro, Carbajo Jesus et Segovia Enrique. « Analysis of the Underwater Radiated Noise Generated by Hull Vibrations of the Ships ». Sensors 23, n^o 2 (16 janvier 2023) : 1035. http://dx.doi.org/10.3390/s23021035.

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Shipping traffic is recognised as the main man-noise source of the anthropogenic noise generated in the marine environment. The underwater acoustic pollution is increased due to the increment of the human activity at seas supposing a threat for marine habitats. The ship as acoustic source must be understood and controlled to manage the maritime areas both in time and space to reduce the impact of noise in marine fauna. Shipping noise is mainly composed of flow noise, propeller noise and machinery noise. This research is focused on the analysis and estimation of the underwater radiated noise generated by the vibrations of the onboard machinery or structure-borne noise based on the calculation of the transfer function. This function relates the acceleration levels of the vibrations of the hull’s panels and the radiated noise by them using the radiation efficiency. Different analytical methods to estimate the radiation efficiency are presented and compared with data collected at sea. The measurements are performed acquiring simultaneously acceleration and acoustic levels by means on accelerometers installed on the hull’s panels at different positions and hydrophones deployed close to the bow, middle and stern of the ship. The analysis of the transmission of the vibrations along the ships is performed using the data from different locations of the hydrophones. The quality of the measurements is analysed using the coherence function through the spectral correlation between the measurement of vibrations and acoustic levels. On the other hand, signal-to-noise ratio is computed to verify the strength of the noise sources. The computed transfer function is used to predict the underwater radiated noise from vibrations showing differences less than 2 dB re to 1 μPa2.

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Yan, Xuefan. « Integrated control method for electromagnetic compatibility of lift facility control system for naval craft ». Journal of Physics : Conference Series 2296, n^o 1 (1 juin 2022) : 012013. http://dx.doi.org/10.1088/1742-6596/2296/1/012013.

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Abstract Lifting facilities electromechanical servo system has a compact structure, high specific power, high control accuracy, low vibration and noise, high reliability. In recent years, small and medium power electromechanical servo systems have been widely used in the aerospace field, and the application of distributed high-power electromechanical servo systems in the naval field to replace the traditional valve-controlled centralized ship-wide hydraulic servo system has a broad application prospect, becoming one of the important links to achieve a new generation of "all-electric" ships. But along with the power level, electromechanical servo system electromagnetic compatibility problems are increasingly prominent, and must be considered from the system design in a comprehensive manner. This paper takes a ship electromechanical servo system as an example, starts from the system functional unit, combines the ship and servo system electromagnetic environment characteristics, sorts out the key links of each unit electromagnetic compatibility control, and takes targeted measures in the electromagnetic compatibility design, the product finally passed the electromagnetic compatibility test, which can provide reference for electromechanical servo system electromagnetic compatibility design.

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Liu, Hongmin, Zhiwei Lian, Zhihao Gong, Yichu Wang et Guojun Yu. « Thermal comfort, vibration, and noise in Chinese ship cabin environment in winter time ». Building and Environment 135 (mai 2018) : 104–11. http://dx.doi.org/10.1016/j.buildenv.2018.02.041.

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Kim, Min Gi, Won Woo Hwang et Soo Hun Lee. « The Identification of Relationship between Vibration and Noise of Universal Motor in Working Status ». Key Engineering Materials 321-323 (octobre 2006) : 1616–19. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1616.

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As the home appliances are systemized, they have complicatedly assembled structure. It is reasonable to see the noise problem of home appliance in the viewpoint of system like vehicle and ship. There are various system analysis methods to resolve the noise problem [1-3]. To use system analysis methods, the system information like modal and path properties must be gathered and analyzed. But it takes many times to find out the system properties, so the simpler system analysis methods are needed. The coherence analysis method is useful as the system analysis method, since the method can identify the system property like the relationship between inputs and outputs directly and simply. In the paper, the partial coherence analysis is used for identification of the MISO system of washing machine, in which multi-input signals are vibration signals of motor bracket and an output signal is noise signal of washing machine. The relationship between the noise of washing machine and the vibration of the motor bracket in working status was identified and the parts of bracket closely correlated with noise were also proved by the relationship. And the noise of washing machine was controlled by redesigning the parts of bracket associated with the noise of washing machine based on the coherence function in octave band.

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Пятакович, В. А., В. Ф. Рычкова et А. П. Пурденко. « Mathematical models for evaluating the effectiveness of shock-absorbing fasteners of vibro-active mechanisms of marine objects by vibrational power ». MORSKIE INTELLEKTUAL`NYE TEHNOLOGII)</msg> ;, n^o 4(54) (2 décembre 2021) : 13–20. http://dx.doi.org/10.37220/mit.2021.54.4.083.

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Для создания виброакустической защиты судового оборудования необходимо учитывать потоки колебательной энергии, распространяющиеся от источников как через опорные и неопорные связи, так и в виде воздушного шума. В работе представлены математические модели оценки эффективности амортизирующих креплений виброактивных механизмов морских объектов по колебательной мощности, учитываемые при обучении разрабатываемой нейросетевой системы классификации морских целей. Теоретические разработки в области виброзащиты и виброизоляции во многом имеют междисциплинарный характер и опираются на методы теории механизмов и машин, теоретической механики, теории колебаний, теории управления, используются методы инфорьт мационные технологии для оценки, поиска и выбора рациональных проектно-конструкторских решений. Создание амортизирующих устройств, способных защитить объекты от вибраций и ударов и, вместе с тем, обладающих ограниченными размерами, является сложной технической проблемой. В связи с этим первостепенное значение приобретают вопросы теории и расчета адаптивных виброзащитных систем. To create vibro-acoustic protection of ship equipment, it is necessary to take into account the flows of vibrational energy propagating from sources both through support and non-support connections, and in the form of air noise. The paper presents mathematical models for evaluating the effectiveness of shock-absorbing fasteners of vibro-active mechanisms of marine objects by vibrational power, which are taken into account when training the developed neural network system for classifying marine targets. Theoretical developments in the field of vibration protection and vibration isolation are largely interdisciplinary in nature and are based on the methods of the theory of mechanisms and machines, theoretical mechanics, vibration theory, control theory, information technology methods are used to evaluate, search and select rational design solutions. The creation of shock-absorbing devices that can protect objects from vibrations and shocks and, at the same time, have limited dimensions is a complex technical problem. In this regard, the issues of the theory and calculation of adaptive vibration protection systems are of paramount importance.

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程, 果. « Personnel Training Plan for the Ship Vibration and Noise Reduction Discipline in Military Academies ». Advances in Education 12, n^o 01 (2022) : 200–207. http://dx.doi.org/10.12677/ae.2022.121035.

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Korobitsina, D., et A. Kuznetsova. « Acoustic lifetime of anti-vibration coating and its effect upon noise in ship spaces ». TRANSACTIONS OF THE KRYLOV STATE RESEARCH CENTRE S-I, n^o 2 (2 septembre 2019) : 104–9. http://dx.doi.org/10.24937/2542-2324-2019-2-s-i-104-109.

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Zheng, H., G. R. Liu, J. S. Tao et K. Y. Lam. « FEM/BEM analysis of diesel piston-slap induced ship hull vibration and underwater noise ». Applied Acoustics 62, n^o 4 (avril 2001) : 341–58. http://dx.doi.org/10.1016/s0003-682x(00)00046-3.

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WAFUKA, Kodai, Tadahiro ARAKI, Mitsuru KITAMURA et Akihiro TAKEZAWA. « The study of finite element capable of expressing vibration mode relating to ship noise. » Proceedings of Design & ; Systems Conference 2017.27 (2017) : 3303. http://dx.doi.org/10.1299/jsmedsd.2017.27.3303.

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Ma, Xiyue, Lei Wang et Jian Xu. « Active Vibration Control of Rib Stiffened Plate by Using Decentralized Velocity Feedback Controllers with Inertial Actuators ». Applied Sciences 9, n^o 15 (5 août 2019) : 3188. http://dx.doi.org/10.3390/app9153188.

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Active control of low frequency vibration and sound radiation from a rib stiffened plate has great practical significance as this structure is widely applied in engineering, such as aircraft or ship fuselage shells. This paper presents an investigation on the performance of active vibration control of the rib stiffened plate by using decentralized velocity feedback controllers with inertial actuators. A simple modeling approach in frequency domain is proposed in this research to calculate the control performance. The theoretical model of vibrating response of the ribbed plate and the velocity feedback controllers is first established. Then, as an important part, the influences of the control gain and the number of the decentralized unit on the control performance are investigated. Results obtained demonstrate that—similar to that of the unribbed plate case—appropriately choosing the number of the unit and their feedback gains can achieve good control results. Too many units or very high feedback gains will not bring further noise reduction.

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Ding, Zheyu, Hongbai Bai, Yiwan Wu, Yue Zhu et Yichuan Shao. « Experimental Investigation of Thermal Modal Characteristics for a Ship’s Foundation under 300°C ». Shock and Vibration 2019 (20 mai 2019) : 1–11. http://dx.doi.org/10.1155/2019/2714930.

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How to further reduce vibration and noise is a major challenge for modern ship design. High-temperature environment will significantly influence the mechanical properties (such as elastic modulus and stiffness) of the ship’s foundation. These properties will have a serious impact on the inherent vibration characteristics of the foundation. In this paper, a simplified foundation is taken as the research object, and a thermal-vibration joint test system is developed for investigating the thermal modal characteristics of the foundation under different temperatures. The joint test system consists of a transient aerodynamic heating environment simulation system and a vibration excitation and acquisition system. Finite element method (FEM) is used to analyze the distribution of thermal fields. The influence of the ceramic rods and the different ambient temperatures on the modal characteristics of the foundation is studied. The results indicate that the effect of ceramic rods on the modal characteristic of the foundation is negligible. The results also show that the greater the vibration response amplitude is as the temperature increases and the first-order natural frequency does not change, the smaller the second-order natural frequency and the damping ratio will become smaller. The variation of natural frequency and damping ratio of the foundation under different temperature conditions can provide a reliable experimental basis for the design of the vibration and noise reduction of the ship’s foundation in the thermal-vibration environment.

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Huang, Ye-qing, Song-lin Nie, Hui Ji et Shuang Nie. « Vibration Analysis and Experimental Research of the Linear-Motor-Driven Water Piston Pump Used in the Naval Ship ». Shock and Vibration 2016 (2016) : 1–13. http://dx.doi.org/10.1155/2016/4608328.

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Aiming at the existing problems of traditional water piston pump used in the naval ship, such as low efficiency, high noise, large vibration, and nonintelligent control, a new type of linear-motor-driven water piston pump is developed and its vibration characteristics are analyzed in this research. Based on the 3D model of the structure, the simulation analyses including static stress analysis, modal analysis, and harmonic response analysis are conducted. The simulation results reveal that the mode shape under low frequency stage is mainly associated with the eccentricity swing of the piston rod. The vibration experiment results show that the resonance frequency of linear-motor-driven water piston pump is concentrated upon 500 Hz and 800 Hz in the low frequency range. The dampers can change the resonance frequency of the system to a certain extent. The vibration under triangular motion curve is much better than that of S curve, which is consistent with the simulation conclusion. This research provides an effective method to detect the vibration characteristics and a reference for design and optimization of the linear-motor-driven water piston pump.

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Li, Wei Sheng, et Pan Lu. « Design of Shipborne Reducer Box Damping in Reducing Vibration ». Applied Mechanics and Materials 455 (novembre 2013) : 585–92. http://dx.doi.org/10.4028/www.scientific.net/amm.455.585.

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The structure noise of marine gear reducer seriously affects the concealment of ships, the stability of transmission system and comfort of crew's working environment. There are many ways to control structural vibrations, in which adding damping structure into reducer box is an effective measure to restrain the resonance. Aiming at the excessive vibration of box 240569 node, this paper realized the design of damping reducing vibration with the method of shell structure damping design finite element. Finally, the authors verified vibration during box reducer normal operation through harmonic response analysis.

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Vlahopoulos, Nickolas, Kuangcheng Wu et Sergey Medyanik. « Energy Finite Element Analysis for Structural-Acoustic Design of Naval Vehicles ». Journal of Ship Production and Design 28, n^o 01 (1 février 2012) : 42–48. http://dx.doi.org/10.5957/jspd.2012.28.1.42.

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The pursuit of innovative ship designs, the use of new materials, and the increasingly demanding performance requirements dictate a broadly focused thrust for addressing noise and vibration issues during the design process. This expanded technical view also requires that the types of tools used for these assessments can provide results within a short enough time to affect the design cycle. Recently, an Energy Finite Element Analysis (EFEA) formulation has been developed for computing the vibration and the associated radiated noise of complex vehicles at frequencies where conventional finite element methods are no longer efficient. In this paper the main theoretical aspects of the EFEA are presented first. Next, a substructuring capability is described where large computational models, typical of naval applications, can be subdivided into separate domains for pursuing a compartmentalized solution and achieving further improvements in computational efficiency. Finally, validation case studies are presented with correlation between computations and scaled model testing.

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Choi, Woen-Sug, Suk-Yoon Hong, Hyun-Wung Kwon, Jeong-Hwa Seo, Shin-Hyung Rhee et Jee-Hun Song. « Estimation of turbulent boundary layer induced noise using energy flow analysis for ship hull designs ». Proceedings of the Institution of Mechanical Engineers, Part M : Journal of Engineering for the Maritime Environment 234, n^o 1 (4 juin 2019) : 196–208. http://dx.doi.org/10.1177/1475090219852195.

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A turbulent boundary layer develops on the surface of submerged bodies in motion; these layers consist of complex flows and interact with the structure causing turbulent boundary layer induced noise due to fluid-structure interaction. Recently, although the research on such noise has attracted great interest in the naval fields, owing to the focus on the competitive development of low-noise naval ships, the limitations corresponding to the application of methods developed in aeroacoustics for underwater structures having lower convection speed of turbulence and faster sound speed along with insufficient environments to conduct experiments restrained to subjects of simple structures at high frequency. To overcome the abovementioned limitations and study the noise characteristics for ship hull design, in this research, methods to analyze the noise radiated due to turbulent flow on the complex underwater structure are developed using energy flow analysis methods for vibro-acoustic calculations. For estimation of the input hydrodynamic forces, wall pressure fluctuation spectrum on the surface is obtained from turbulent boundary layer properties to acquire sufficient resolutions. The vibrational response of the structure is calculated using energy flow analysis incorporating the finite element method for structural forces estimated as input power. The acoustical response coupled with the vibrational response is obtained using the calculated vibrational energy density with the boundary element method in combination with the energy flow analysis, taking advantages of the fact that the methods share the common energy variables. Developed methods are validated with a case of broadband noise radiated from a plate. Using the procedures, numerical estimation and analysis of acoustic performance are performed for trimaran ship hull designs with steady-state computational fluid dynamics to demonstrate the method’s usability as an assessment tool in the early design stage.

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Cho, Yang-Uk, et Gyu-Hong Kang. « A Study on the Noise and Vibration Analysis of 200kW PMSM for Electric Propulsion Ship ». Journal of international Conference on Electrical Machines and Systems 3, n^o 4 (1 décembre 2014) : 389–93. http://dx.doi.org/10.11142/jicems.2014.3.4.389.

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Pang, Fu-zhen, Chuang Wu, Xu-hong Miao et Hong-bao Song. « Tranferred boundary similarity method and application to the prediction of ship vibration and radiated noise ». Noise Control Engineering Journal 63, n^o 4 (1 juillet 2015) : 318–30. http://dx.doi.org/10.3397/1/376328.

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Hwang, Hong-Sik, Kwang-Jun Paik, Soon-Hyun Lee et Gisu Song. « Numerical Study on the Vibration and Noise Characteristics of a Delft Twist11 Hydrofoil ». Journal of Marine Science and Engineering 9, n^o 2 (30 janvier 2021) : 144. http://dx.doi.org/10.3390/jmse9020144.

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Underwater radiated noise (URN) is greatly increasing due to an increase in commercial shipping, sonar activities, and climate change. As a result, marine life is having difficulty communicating, and marine ecosystem disturbances are occurring. The noise from the cavitation of propellers is affecting URN. Cavitation is a phenomenon in which rapid changes of pressure in a liquid lead to the formation of small vapor-filled cavities in places where the pressure is relatively low. This phenomenon results in poor efficiency of the propeller or turbine of a ship and noise, vibration, and erosion. For these reasons, this study examines the URN of sheet and cloud cavitation. A numerical analysis was done using a Delft Twist11 hydrofoil. The URN resulting from cloud cavitation and sheet cavitation was compared with the numerical results of previous studies. The results showed that URN normally increases due to pressure fluctuations when cavitation occurs. URN increased more significantly in conditions of cloud cavitation than in cavitation inception. It is also shown that a frequency begins to occur after the occurrence of the cloud cavitation, and the frequency grew as the cavitation fully developed.

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Hu, Yu Long, Sheng Huang, Yuan Hang Hou, Xiang Yin Meng, Wen Quan Wang et Chao Wang. « The Application of Fuzzy Modeling and PSO in Spaces Allocation of Naval Ship ». Advanced Materials Research 201-203 (février 2011) : 1238–42. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.1238.

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A semi-automated general arrangement technique of naval ship is discussed, it approached by a series of two essentially two-dimensional problems: the allocation of spaces to Zone-decks (one deck within one vertical zone), after that, implement the detailed arrangement of spaces to each Zone-deck. In this context, fuzzy modeling is introduced for evaluating environmental loadings (noise, vibration and ship motion) and Naval Equipment Standards, and then these measures are translated to fuzzy utility values which express the satisfaction location of each group spaces. The fuzzy location preference values are combined with Zone-deck utilization utility to establish the objective function using fuzzy product inference. Lastly, the particle swarm optimization (PSO) is performed on the objective function to acquire the allocation plan of spaces in each Zone-deck.

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Weyna, Stefan. « The Use of Acoustic Vectors Decomposition of Sound Fields to Vibroacoustic Protection on Ships ». Archives of Acoustics 42, n^o 2 (27 juin 2017) : 207–12. http://dx.doi.org/10.1515/aoa-2017-0023.

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Abstract In this paper, numerous examples will be illustrated as principles of applying the sound intensity measurements to practical problems at the noise abatement on ships and offshore constructions. The paper presents the results of transmission loss measurements together with flanking transmission for ship bulkheads and partitions with doors and windows. Investigations carried out with sound intensity measurement techniques will be compared against those made by classical methods. Finally for a few examples, the graphic presentation of spatial distribution of sound intensity vectors risen close to vibrating ship cabin partitions and inside the cabin will be shown in 2D and 3D graphical form. As a result, a two-dimensional acoustic wave flow map of time-averaged active intensity vectors propagated along curved streamlines and a vector perpendicular to measured plane are graphically illustrated. The technique of acoustic vectors decomposition of sound fields described, can enrich the knowledge of the mechanism of acoustic energy flux through ship partitions.

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Kulichkova, E. A., V. A. Kozlov et G. A. Tyumentsev. « ABOUT AN APPROACH TO DETERMINING ACTIONS TO INCREASE THE TECHNICAL AND ECONOMIC EFFICIENCY OF ACOUSTIC TESTING ». Journal of Dynamics and Vibroacoustics 5, n^o 3 (12 mars 2020) : 37–40. http://dx.doi.org/10.18287/2409-4579-2019-5-3-37-40.

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Shipboard valves in the design and production are subjected to a variety of tests, including such specific types of tests as acoustic, necessary to determine the noise level created by the product.With stricter requirements for perspective marine equipment, the requirements for the accuracy of tests conducted on ship pipeline fittings as a source of acoustic noise are increasing. Taking into account that the main bench equipment was designed and built more than 30 years ago, when the influence of external factors (such as the impact of vibration caused by the increased traffic load and the development of the metro) was not so significant, a comprehensive study of approaches is needed to increase the accuracy of tests on the existing stand equipment, taking into account the increased level of external interference.

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