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Wyszukujesz frazę "Li, Y.Y." wg kryterium: Autor


Tytuł:
Simulation model and state analysis of ship transmission line
Autorzy:
Hu, Y.
Xu, M.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/259613.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship power
transmission line
simulation model
insulation deterioration
Opis:
In order to discuss the simulation model of the ship transmission line and the state of the transmission line, an early fault model is built according to the evolution principle of the short circuit fault of the transmission line and combining with the fault characteristics of the early fault. A small distributed ship transmission line system is built in MATLAB/ Simulink. Then, combined with the constructed fault module, the original short circuit module, and the load module, the various states (normal state, early fault state, severe early fault state, short circuit state) of the ship transmission line are stimulated, and the features of voltage signal in each state is analysed. It is concluded that, due to the normal operation of the ship transmission line system, the variation characteristics of the flow signal and voltage signal caused by the sudden load mutation, that is, the sudden load and the sudden increase load, are very similar to the changes caused by the early fault. Therefore, in order to find a more accurate early fault detection method, the state is divided into normal state, sudden load state, sudden increase and sudden decrease load state.
Źródło:
Polish Maritime Research; 2018, S 3; 36-42
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on intelligent diagnosis method for large-scale ship engine fault in non-deterministic environment
Autorzy:
Feng, D.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/258452.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
non-determinism
large-scale ship engine
fault intelligent diagnosis
Opis:
Aiming at the problem of inaccurate and time-consuming of the fault diagnosis method for large-scale ship engine, an intelligent diagnosis method for large-scale ship engine fault in non-deterministic environment based on neural network is proposed. First, the possible fault of the engine was analyzed, and the downtime fault of large-scale ship engine and the main fault mode were identified. On this basis, the fault diagnosis model for large-scale ship engine based on neural network is established, and the intelligent diagnosis of engine fault is completed. The experiment proved that the proposed method has high diagnostic accuracy, engine fault diagnosis takes only about 3s, with a higher use value.
Źródło:
Polish Maritime Research; 2017, S 3; 200-206
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulations of linearly stratified flow past submerged bodies
Autorzy:
Ma, W.
Li, Y.
Ding, Y.
Hu, K.
Lan, L.
Powiązania:
https://bibliotekanauki.pl/articles/259150.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
stratified flow
circular cylinder
internal wave
Suboff
equation of state
Opis:
In this study, a methodology was presented to predict density stratified flows in the near-field of submerged bodies. The energy equation in temperature form was solved coupled with momentum and mass conservation equations. Linear stratification was achieved by the definition of the density as a function of temperature. At first, verifications were performed for the stratified flows passing a submerged horizontal circular cylinder, showing excellent agreement with available experimental data. The ability of the method to cope with variable density was demonstrated. Different turbulence models were used for different Re numbers and flow states. Based on the numerical methods proposed in this paper, the stratified flow was studied for the real scale benchmark DAPRA Suboff submarine. The approach used the VOF method for tracing the free surface. Turbulence was implemented with a k − ω based Detached Eddy Simulation (DES) approach. The effects of submarine speed, depth and density gradient on the free surface wave pattern were quantitatively analyzed. It was shown that, with the increasing of the speed of the submarine, the wavelength and wave height of the free surface wave were gradually increasing. The wave height of the free surface wave was gradually reduced as the submarine’s depth increased. Relative to the speed and submarine depth, the changes of the gradient density gradient have negligible effects on the free surface wave field.
Źródło:
Polish Maritime Research; 2018, S 3; 68-77
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydraulic analysis of leakage from submarine pipe network
Autorzy:
Li, J. H.
Fan, Y. T.
Powiązania:
https://bibliotekanauki.pl/articles/258776.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
submarine pipe network
leakage
transient flow
Opis:
The leakage from submarine pipe network is investigated by a numerical model in this paper. A whole event including of the steady flow before the leakage, the transient flow during the leakage and the steady flow after the leakage is considered in the model. The numerical results of the discharge and the head compare with the theoretical solution under the condition of steady flow. Good agreement is obtained. The numerical results of the discharge and the head show that the discharge and the head in each pipe changes suddenly after the leakage occurring. The abrupt trend of the discharge in each pipe is not same completely. Some change upwards, while others downwards. However, the abrupt trend of the head is always downward. The effects of leakage discharge on the transient flow are also investigated. It is founded that the larger the leakage discharge, the more obvious the abrupt trend of the discharge and the head before or after the leakage is.
Źródło:
Polish Maritime Research; 2015, S 1; 48-55
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model tests for shallow-water ship maneuverability in Three Gorges Reservoir
Autorzy:
Cai, C.
Cai, X.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/259922.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
shallow-water test of ship model
simulated computation
maneuverability calibration
scale effect
Z shape test
K and T indexes
navigation safety
Opis:
This paper conducts calibration tests on the shallow-water maneuverability of 1:100 ship models for the typical navigation fleets in Three Gorges Reservoir. Major influential factors for the maneuverability similitude between models and prototypes and for scale effect were identified. A correction method for model scale was also established through model tests. Test results indicate that, by correcting the model scales of various fleets based on scale effect, the maneuverability indexes K’ (dimensionless of K) and T’ (dimensionless of T) of ship models are suitable for shallowwater tests, and properly reflect the maneuvering characteristics of prototypes. The findings provide an experimental basis for the navigation safety in Three Gorges Reservoir.
Źródło:
Polish Maritime Research; 2015, S 1; 136-140
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elastic-plastic analysis for circumferential through crack at boundary of semi’s brace under beam wave
Autorzy:
Wang, F.
Deng, X.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/260258.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
theoretical model
crack damaged brace
semi-submersible platform
beam wave
Opis:
In order to ensure the safety and reliability of the horizontal brace of semi-submersible platform (SEMI) which functions as the supporting structure in SEMI, this article presents an elastic-plastic method to analyze the variations of the crack tip opening displacement, elastic zone and plastic zone of the cracked section of the horizontal brace under beam wave. The brace of the SEMI was assumed to be located a circumferential through crack at its boundary in this article. In addition, the cracked section of the brace has been divided into crack zone, tensile plastic zone, elastic zone and compressive plastic zone in the presented theoretical model. Moreover, the closed form of the solution has been found in this article which is especially suitable solving complicated problems in practical engineering application. Also, a typical new-generation SEMI that is in practical use was selected to analyze the variation tendency of the cracked brace’s parameters using the proposed model which could give good suggestion to semi-submersible platform designers and managers.
Źródło:
Polish Maritime Research; 2018, 4; 106-113
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Visualization investigation on the marine data with multivariate statistical analysis methods
Autorzy:
Li, Y.
Lu, Z.
Wang, M.
Powiązania:
https://bibliotekanauki.pl/articles/260477.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine data
factor analysis
cluster analysis
discriminate analysis
visualization
Opis:
Marine information is an important way for us to know and study more about the ocean. Marine data makes the basic of marine information. Because of the huge quantity and diversity of marine data, and at the same time marine data is polyatomic variable, we start with statistical analysis methods to search for the regularity of the marine data. On one hand, we get the aggregate variation functions of the marine data by factor analyzing in aspect of the spatiality. Then we visually describe the marine status of the studied sea area with pre variogram function and post variogram function. On the other hand, we used cluster analysis method to get the verifying rule in time and make visible graphs of the marine data. In this way, we can also supply with the suggestions in classifying the sea seawater quality. The data processing result shows that the suggested methods in this article are both operable and effective. At the same time some reasonable suggestions are given in the article.
Źródło:
Polish Maritime Research; 2017, S 2; 89-94
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anti-seismic device design for container crane and its elastic-plastic time history analysis
Autorzy:
Dong, D.
Li, J.
Teng, Y.
Powiązania:
https://bibliotekanauki.pl/articles/963365.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
quayside container crane
time history analysis
energy design method
anti-seismic device
Opis:
Quayside container crane is a kind of large dimension steel structure, which is the major equipment used for lifting container at modern ports. With the aim to ensure the safety and reliability of the crane under seismic loads, an anti-seismic device is designed. To validate the efficiency and reliability of the anti-seismic device, elastic-plastic time history analysis under rare seismic intensity is carried out. And the results of elastic-plastic time history analysis when the crane installed anti-seismic device and uninstalled the device are compared.
Źródło:
Polish Maritime Research; 2015, S 1; 30-34
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of irregular waves in a numerical wave tank
Autorzy:
Li, Z-F.
Shi, Y. Y.
Ren, H. L.
Li, H.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/260392.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
open boundary condition
multi transmitting formula
irregular waves
boundary element method
numerical wave tank
Opis:
The time domain boundary element method was utilized to simulate the propagation of the irregular waves in a numerical wave tank. The problem was solved in a time-marching scheme, upon the irregular waves being fed through the inflow boundary, in which the theoretical solution was obtained from the wave energy spectrum. The open boundary condition was modeled by the multi transmitting formula (MTF), in which the phase velocity was calculated according to the Sommerfeld’s condition. The velocity potential and wave elevation were directly obtained by integrating the free surface condition twice, with respect to time. The accuracy of the developed numerical scheme was verified by simulating the propagation of irregular waves. The numerical results show good agreements with the analytical solutions, which prove that the proposed scheme is a promising way to the simulation of wave-body interactions.
Źródło:
Polish Maritime Research; 2015, S 1; 21-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the optimization and performance of TDMA allocation algorithm in ships’ ad hoc networks
Autorzy:
Han, X.
Li, Y.
Liu, G.
Powiązania:
https://bibliotekanauki.pl/articles/259367.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
timeslot allocation algorithm
ships
ad hoc network
Opis:
This paper analyzes the requirements of the information transmission network of ship integrated condition monitoring system, and proposes a design scheme of ship condition monitoring system based on wireless ad hoc network. The wireless ad hoc network protocol was designed, its networking process was analyzed in detail, and the network transmission performance of the monitoring system was tested. The results proved the feasibility of the system. The above solution can be used for the transmission of ship state information that satisfies the requirements of wireless transmission, and has important theoretical and practical significance. The slot allocation algorithm has been receiving extensive attention as an important part of the TDMA system research. This paper analyzes the summarization and summarization of TDMA time slot assignment algorithms from several aspects such as slot synchronization, existing slot allocation algorithm, and slot assignment model, laying an important foundation for researchers to do further research. In the TDMA system, time is divided into non-overlapping time frames, and the time frames are divided into non-overlapping time slots. Each node in the network performs corresponding operations in each time slot.
Źródło:
Polish Maritime Research; 2018, S 2; 170-175
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the statistical characteristics of crosstalk in naval ships wiring harness based on Polynomial Chaos Expansion method
Autorzy:
Chi, Y.
Li, B.
Yang, X.
Wang, T.
Yang, K.
Gao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/260090.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
naval ships wiring harness
crosstalk
Polynomial Chaos Expansion
statistical characteristics
Opis:
Crosstalk in wiring harness has been studied extensively for its importance in the naval ships electromagnetic compatibility field. An effective and high-efficiency method is proposed in this paper for analyzing Statistical Characteristics of crosstalk in wiring harness with random variation of position based on Polynomial Chaos Expansion (PCE). A typical 14-cable wiring harness was simulated as the object of research. Distance among interfering cable, affected cable and GND is synthesized and analyzed in both frequency domain and time domain. The model of naval ships wiring harness distribution parameter was established by utilizing Legendre orthogonal polynomials as basis functions along with prediction model of statistical characters. Detailed mean value, mean square error, probability density function and reasonable varying range of crosstalk in naval ships wiring harness are described in both time domain and frequency domain. Numerical experiment proves that the method proposed in this paper, not only has good consistency with the MC method can be applied in the naval ships EMC research field to provide theoretical support for guaranteeing safety, but also has better time-efficiency than the MC method. Therefore, the Polynomial Chaos Expansion method.
Źródło:
Polish Maritime Research; 2017, S 2; 205-214
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation and measurement of tide height for the navigation of ship at high tide using artificial neural network
Autorzy:
Li, Q.
Bing-Dong, Y.
Bi-Guang, H.
Powiązania:
https://bibliotekanauki.pl/articles/258480.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
deep-draft ships
neural network
intelligent navigation
multi-observation stations
Opis:
Accurate tide height is crucial for the safe navigation of large deep-draft ships when they enter and leave the port. We have proposed an accurate forecasting method for the tide heights from the observation data and neural networks, which can easily calculate the tidal window period of large deep-draft ships’ navigation through long channels at high tide. Moreover, an artificial neural network is established for the tide height from the observation of tide heights before their current time node. For an ideal forecast, the neural network was optimized for one year with the tide height data of Huanghua Port. In case of large ships, their tidal characteristics of channels for are complex. A new method is proposed for the observation of multiple stations and artificial neural networks of each observation station. When ships are navigating through the port, the tide height is predicted from the observed data and forecast tide heights of multiple observation stations. Thus, a valid tidal window period is secured when the ships enter the port. Comparative analysis of the ship’s tidal window period with that of the measured one can lead us to conclude that the forecasted data has a strong correlation with the measurement. So, our proposed algorithm can accurately predict the tide height and calculate the node timing when the ship enters and depart the port. Finally, these results can be applied for the safe navigation of large deep-draft ships when the port is at high tide.
Źródło:
Polish Maritime Research; 2018, S 3; 99-110
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Yellowfin tuna (Thunnusalbacares) fishing ground forecasting model based on bayes classifier in the South China Sea
Autorzy:
Zhou, W.
Li, A.
Ji, S.
Qiu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/258994.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Bayes classifier
South China Sea
yellowfin tuna
fishing ground forecasting
Opis:
Using the yellowfin tuna (Thunnusalbacares,YFT)longline fishing catch data in the open South China Sea (SCS) provided by WCPFC, the optimum interpolation sea surface temperature (OISST) from CPC/NOAA and multi-satellites altimetric monthly averaged product sea surface height (SSH) released by CNES, eight alternative options based on Bayes classifier were made in this paper according to different strategies on the choice of environment factors and the levels of fishing zones to classify the YFT fishing ground in the open SCS. The classification results were compared with the actual ones for validation and analyzed to know how different plans impact on classification results and precision. The results of validation showed that the precision of the eight options were 71.4%, 75%, 70.8%, 74.4%, 66.7%, 68.5%, 57.7% and 63.7% in sequence, the first to sixth among them above 65% would meet the practical application needs basically. The alternatives which use SST and SSH simultaneously as the environmental factors have higher precision than which only use single SST environmental factor, and the consideration of adding SSH can improve the model precision to a certain extent. The options which use CPUE’s mean ± standard deviation as threshold have higher precision than which use CPUE’s 33.3%-quantile and 66.7%-quantile as the threshold
Źródło:
Polish Maritime Research; 2017, S 2; 140-146
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on optimization simulation of SCR denitration system for marine diesel engine
Autorzy:
Du, J.
Li, R. N.
Wu, X.
Zhang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/259646.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine diesel engine
SCR system
flue gas
flow deflector
Opis:
With the rapid development of shipbuilding industry exhaust world is also very harmful one kind of environmental issues, and the ship marine diesel engine exhaust gas is mainly produced, so in recent years it has developed a diesel engine SCR system. SCR system can control emissions of nitrogen oxides in the exhaust of vessel, furthermore air pollution can be reduced. The main goal of article was using fluent software to correct SCR system selection and flue gas flow under different size best deflector arrangement is simulated. Next goal is further optimize the structure of the SCR system.
Źródło:
Polish Maritime Research; 2018, S 3; 13-21
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended elliptic mild slope equation incorporating the nonlinear shoaling effect
Autorzy:
Xiao, Q. L.
Li, Ch. H.
Fu, X. Y.
Wang, M. J.
Powiązania:
https://bibliotekanauki.pl/articles/258718.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
nonlinear dispersion relation
nonlinear shoaling coefficient
extended elliptic mild slope equation
surf zone
wave transformation
Opis:
The transformation during wave propagation is significantly important for the calculations of hydraulic and coastal engineering, as well as the sediment transport. The exact wave height deformation calculation on the coasts is essential to near-shore hydrodynamics research and the structure design of coastal engineering. According to the wave shoaling results gained from the elliptical cosine wave theory, the nonlinear wave dispersion relation is adopted to develop the expression of the corresponding nonlinear wave shoaling coefficient. Based on the extended elliptic mild slope equation, an efficient wave numerical model is presented in this paper for predicting wave deformation across the complex topography and the surf zone, incorporating the nonlinear wave dispersion relation, the nonlinear wave shoaling coefficient and other energy dissipation factors. Especially, the phenomenon of wave recovery and second breaking could be shown by the present model. The classical Berkhoff single elliptic topography wave tests, the sinusoidal varying topography experiment, and complex composite slopes wave flume experiments are applied to verify the accuracy of the calculation of wave heights. Compared with experimental data, good agreements are found upon single elliptical topography and one-dimensional beach profiles, including uniform slope and step-type profiles. The results indicate that the newly-developed nonlinear wave shoaling coefficient improves the calculated accuracy of wave transformation in the surf zone efficiently, and the wave breaking is the key factor affecting the wave characteristics and need to be considered in the nearshore wave simulations.
Źródło:
Polish Maritime Research; 2016, S 1; 44-51
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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