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Wyszukujesz frazę "roll motion" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Numerical and analytical approaches for roll motion analysis in regular longitudinal waves
Autorzy:
Peşman, E.
Kolukısa, D. C.
Taylan, M.
Powiązania:
https://bibliotekanauki.pl/articles/258476.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
parametric roll motion
bifurcations
panel method
AQWA
Opis:
In this study numerical and analytical approaches were investigated in terms of accuracy of their results, practicality of solution and ability to reproduce the main features of the parametric roll phenomenon such as loss of stability and bifurcations in parametric roll motion analysis of ships. In general, single-degree-of-freedom analytical approach is based on reducing number of degrees of freedom from 3 to 1 by using the quasi-static Froude-Krylov assumption, incorporating heave and pitch effects by means of a time varying restoring moment. On the other hand, numerical approaches to motion of six and four degrees of freedom are based on three dimensional diffraction/radiation and potential flow theories. In summary, this paper reveals that analytical approaches are sufficiently adequate to obtain accurate practical results for this relatively complex phenomenon.
Źródło:
Polish Maritime Research; 2015, 3; 28-35
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control design of fin roll stabilization in beam seas based on Lyapunov’s direct method
Autorzy:
Karakas, Safak C.
Ucer, Erdem
Pesman, Emre
Powiązania:
https://bibliotekanauki.pl/articles/258999.pdf
Data publikacji:
2012
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
fin stabilizers
Lyapunov function
roll motion
white noise
Opis:
The aim of this study is to design a controller based on Lyapunov’s direct method for fin roll stabilization systems for ships in beam seas. A third order mathematical model consisting of uncoupled roll motion of a ship and fin hydraulic system dynamics is considered. In the model, random wind force is defined by Gaussian white noise. Both controlled and uncontrolled roll motions are presented considering stall effect by roll-time history and safe basin graphics. It is observed from the results that fin control system is successful to reduce erosion percentages of safe basins and roll amplitudes.
Źródło:
Polish Maritime Research; 2012, 2; 25-30
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified pid control design for roll fin actuator of nonlinear modelling of the fishing boat
Autorzy:
Alarçin, F.
Demirel, H.
Su, M. E.
Yurtseven, A.
Powiązania:
https://bibliotekanauki.pl/articles/258902.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
stability analyses
nonlinear roll motion
modified PID
CFD
Opis:
This study aims to reduce roll motion of a fishing boat which arises from disturbing hydrodynamic effects by means of fin roll stabilizer. It is assured that roll motion with nonlinear damping and restoring moment coefficients are down to the desired level through classical PID and modified PID algorithms. At the time of sailing, stability, a very important concept, was examined using Lyapunov direct method taking initial conditions into consideration, and it was noted that the system was generally stable. In addition, NACA 0015 model was used for the fin roll stabilizer, and flow analysis was carried out with Computational Fluid Dynamics (CFD) method. In the simulation results, when the same gains were used, modified PID controller algorithms were relatively more effective compared to PID in the fin roll stabilizer system.
Źródło:
Polish Maritime Research; 2014, 1; 3-8
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship nonlinear roll motion identification using artificial neural network
Autorzy:
Mousavi, Seyed Mohamadreza
Khoogar, Ahmad Reza
Ghassemi, Hassan
Powiązania:
https://bibliotekanauki.pl/articles/24202591.pdf
Data publikacji:
2022
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
nonlinear roll motion
dynamic identification
DTMB 5415
roll decay
artificial neural network
Opis:
The solution of the nonlinear equation for a ship’s rotational motion around its longitudinal axis, even with simplifying assumptions, is complicated. This oscillatory motion, which is known as the roll motion, is generated when the ship sails in the waves, and the irregular behavior of the waves causes time-varying dynamics. Calculating the ship’s roll response is possible by determining roll equation coefficients. In the current study, the coefficients were determined from the dynamic response of the ship using a training feed-forward neural network. The training was carried out in two modes: as a free swing in calm water and forced oscillation in irregular waves. The DTMB 5415 vessel was selected as the case study ship. The results of the simulation by the neural network were validated by numerical analysis and model test results.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2022, 72 (144); 65--74
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Overview of Roll Stabilizers and Systems for Their Control
Autorzy:
Kula, K.S.
Powiązania:
https://bibliotekanauki.pl/articles/117383.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Marine Controllers
Roll Stabilizer
Fin Stabilizer
Non-Linear Process
Multivariable Dynamic Process
Roll Motion
Computer Techniques
Anti-Roll Tanks
Opis:
Ship roll motion in waves can be characterized as a strongly non-linear and multivariable dynamic process which is more affected by disturbances, in general, than by the maximal controlling parameter. The article presents methods of roll motion compensation, the majority of which have been used on ships for many years. Although they are not capable of reducing permanently the error to zero, their potential has still not been used to the full. The operational efficiency of roll motion compensators can be improved using control systems. Research activities are in progress to check the applicability of advanced control methods making use of modern computer techniques. Some of them are mentioned in this paper.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2015, 9, 3; 405-414
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the modeling of car passenger ferryship design parameters with respect to selected sea-keeping qualities and additional resistance in waves
Autorzy:
Cepowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/258828.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
sea-keeping qualities
roll-on/roll-off ferryship
rolling
motion sickness index
lateral accelerations
additional resistance in waves
ship design parameters
modeling
artificial neural networks
optimization
Pareto method
Opis:
This paper presents the modeling of car passenger ferryship design parameters with respect to such design criteria as selected sea-keeping qualities and additional resistance in waves. In the first part of the investigations approximations of selected statistical parameters of design criteria of ferryship were elaborated with respect to ship design parameters. The approximation functions were obtained with the use of artificial neural networks. In the second part of the investigations design solutions were searched for by applying the singleand multi-criterial optimization methods. The multi-criterial optimization was performed by using Pareto method. Such approach made it possible to present solutions in such form as to allow decision makers (shipowner, designer) to select solutions the most favourable in each individual case.
Źródło:
Polish Maritime Research; 2009, 3; 3-10
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of optimum hull form for passenger car ferry with regard to its sea-keeping qualities and additional resistance in waves
Autorzy:
Cepowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/258898.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
sea-keeping qualities
roll-on/roll-off ferry ship
rolling
transverse accelerations
vertical accelerations
motion sickness index
additional resistance in waves
ship hull form
ship design parameters
artificial neural networks
fuzzy logic
Opis:
This paper presents a method which makes it possible to determine optimum hull form of passenger car ferry with regard to selected sea-keeping qualities and additional resistance in waves. In the first phase of investigations a hull form characterized by the highest qualities was selected from the list of similar ships. Next, its optimum dimension ratios were determined. Design criteria were formulated by using a method based on deterministic scenarios, but objective functions of partial targets were determined in the form of artificial neural networks. To select the best design variants elements of fuzzy logic were used, that made it possible a.o. to show merits of the design by means of linguistic variables. Such approach made it possible to find the best hull form and its dimensions from the point of view of all considered criteria simultaneously.
Źródło:
Polish Maritime Research; 2008, 2; 3-11
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of vehicle body roll angle on the motion stability and maneuverability of the vehicle
Autorzy:
Parczewski, K.
Wnęk, H.
Powiązania:
https://bibliotekanauki.pl/articles/133587.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
stability of vehicle motion
suspensions
interaction of the road and tires
roll angle of vehicle body
stabilność ruchu pojazdu
zawieszenie
interakcja drogi i opon
Opis:
The article discusses the impact of design solutions of vehicle suspensions into angles of body roll. It was shown which type of suspensions is better from this point of view. There were examined the dependence of the suspensions parameters on the vehicle body roll angle. The influence of camber angle on the force transmitted to the tire contact with the road surface was analysed. The lateral forces were measured on the test stand. There was tested dependency of lateral forces from the sideslip angle for different angles of camber. Was analysed change of lateral forces generated by camber angle on the vehicle which was made on a scale ~ 1:5 during tests carried out on the testing track. For this purpose, two tests have been selected: first one allowing the measurement in steady motion conditions, the second one with dynamic change of direction of vehicle motion. The graphs show the effect of camber angles on the controllability and stability of the vehicle motion.
Źródło:
Combustion Engines; 2017, 56, 1; 133-139
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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