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Wyszukujesz frazę "Li, M" wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
The cavitation nuclei transient characteristics of Lennard-Jones fluid in cavitation inception
Autorzy:
Fu, Q.
Zhang, B.
Zhao, Y.
Zhu, R.
Liu, G.
Li, M.
Powiązania:
https://bibliotekanauki.pl/articles/259255.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
cavitation nuclei
molecular dynamics simulation
Lennard-Jones fluid
cavitation inception
nucleation
Opis:
In the field of ocean engineering, cavitation is widespread, for the study of cavitation nuclei transient characteristics in cavitation inception, we applied theoretical analysis and molecular dynamics (MD) simulation to study Lennard-Jones (L-J) fluid with different initial cavitation nuclei under the NVT-constant ensemble in this manuscript. The results showed that in cavitation inception, due to the decrease of liquid local pressure, the liquid molecules would enter the cavitation nuclei, which contributed to the growth of cavitation nuclei. By using molecular potential energy, it was found that the molecular potential energy was higher in cavitation nuclei part, while the liquid molecular potential energy changes greatly at the beginning of the cavitation nuclei growth. The density of the liquid and the surface layer changes more obvious, but density of vapor in the bubble changes inconspicuously. With the growth of cavitation nuclei, the RDF peak intensity increased, the peak width narrowed and the first valley moved inner. When cavitation nuclei initial size reduced, the peak intensity reduced, the corresponding rbin increased. With the decrease of the initial cavitation nuclei, the system pressure and total energy achieved a balance longer, and correspondingly, they were smaller. In addition, at the beginning of the cavitation nuclei growth, the total energy and system pressure changed greatly.
Źródło:
Polish Maritime Research; 2018, S 2; 75-84
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pseudo-static experiment and analysis on seismic behavior of the RC columns strengthened by GHPFRCC
Autorzy:
Li, X.
Wang, J.
Luo, M.
Powiązania:
https://bibliotekanauki.pl/articles/259179.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
green high performance fiber reinforced cementitious composites (GHPFRCC)
pseudo-static test
reinforced concrete column
strengthening
seismic performance
Opis:
Green high performance fiber reinforced cementitious composites (GHPFRCC) are a new class of sustainable cementitious composites, employing a high volume of fly ash to replace cement. In addition to increasing the sustainability of the construction environment, GHPFRCC exhibits a high tensile ductility and multiple cracking behaviors in the strainhardening state. These materials can effectively improve the structural energy dissipation capacity and structural durability. In this study, the optimum mixture ratio of GHPFRCC is presented established using an orthogonal experiment for a specific engineering application. The described GHPFRCC sustains the mechanical performance of concrete and is employed as the outer cladding to strengthen concrete columns. The finite element analysis of the material was based on the software ABAQUS and pseudo static experiments were conducted to exhibit retrofitting of GHPFRCC applied in the rehabilitation of seismic-damaged concrete columns. The computed and experimental results showed that GHPFRCC, while incorporating high volume fly ash, can retain significant multiple cracking behaviors. The energy dissipation capacity of the GHPFRCC reinforced concrete (RC) column is better than the comparable unreinforced column.
Źródło:
Polish Maritime Research; 2015, S 1; 56-60
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:
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:
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:
Model of eco-water driving force affecting the evolvement of runoff in the upper Minjiang River Basin
Autorzy:
Jin, H.
Yang, W.
Li, P.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/259476.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
eco-water
remote sensing quantitative retrieval
upper Minjiang River
runoff prediction
Opis:
The amount of eco-water resources reflects the land surface water conservation capability, and the underlying surface condition in the hydrologic cycle. In the upper Minjiang River Basin, the amounts of eco-water resources were retrieved from remotely sensed data during 1992 to 2005. Through regression analysis between the retrieved eco-water data and the climate hydrological data mainly including the temperature, the precipitation, and the runoff in the same period, the model of eco-water driving force affecting the evolvement of runoff was established. The accuracy analysis indicates that the model can well describe the relationship between dry season runoff and its driven factors, the measured data validation proves that the model has high precision and good practicability. The eco-water remote sensing inversion provides a valid method to quantify the land surface water conservation capability, and suggests an interesting approach for the driving function quantitative researches of underlying surface factor in the hydrologic cycle.
Źródło:
Polish Maritime Research; 2016, S 1; 91-96
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
Tytuł:
Stability control of propeller Autonomous Underwater Vehicle based on combined sections method
Autorzy:
Qi, D.
Feng, J.
Liu, A.
Hu, J.
Xu, H.
Li, Y.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/259119.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller AUV
dynamic model
stability control
simulation
Opis:
Learning from the motion principle of quadrotor, a symmetric propeller AUV, which has small size and low velocity is designed. Compared with the AUV equipped with rudders, it has better maneuverability and manipulation at low velocity. According to the Newton-Euler method, the 6 DOF kinematic model and dynamic model of the propeller AUV are established. A stability controller that consists of 3 different PID controllers is designed. It makes the depth and attitude angle as trigger conditions, and the relevant controller is chosen in different moving process. The simulation experiments simulate ideal motion state and disturbed motion state, and experiments results show that the stability controller based on combined sections method can make the best of mature technology of PID, and meet the control requirements in different stages. It has a higher respond speed and accuracy, improving the stability of the propeller AUV under the disturbance of complex ocean currents.
Źródło:
Polish Maritime Research; 2015, S 1; 157-162
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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