scholarly journals Influence of variable acceleration on parametric roll motion of a container ship

2016 ◽  
Vol 4 (3) ◽  
pp. 205-214
Author(s):  
Emre Peşman
Author(s):  
Manases Tello Ruiz ◽  
Jose Villagomez ◽  
Guillaume Delefortrie ◽  
Evert Lataire ◽  
Marc Vantorre

Abstract The IMO Intact Stability Code considers the parametric rolling phenomenon as one of the stability failure modes because of the larger roll angles attained. This hazardous condition of roll resonance can lead to loss of cargo, passenger discomfort, and even (in the extreme cases) the ship’s capsize. Studies as such are mostly conducted considering wave characteristics corresponding to wave lengths around one ship length (λ ≈ LPP) and wave amplitudes varying from moderate to rough values. These wave characteristics, recognised as main contributors to parametric rolling, are frequently encountered in deep water. Waves with lengths of such magnitudes are also met by modern container ships in areas in close proximity to ports, but with less significant wave amplitudes. In such areas, due to the limited water depth and the relatively large draft of the ships, shallow water effects influence the overall ship behaviour as well. Studies dedicated to parametric rolling occurrence in shallow water are scarce in literature. In spite of no accidents being yet reported in such scenarios, its occurrence and methods for its prediction require further attention; this in order to prevent any hazardous conditions. The present work investigates the parametric roll phenomenon numerically and experimentally in shallow water. The study is carried out with the KRISO container ship (KCS) hull. The numerical investigation uses methods available in literature to study the susceptibility and severity of parametric rolling. Their applicability to investigate this phenomenon in shallow water is also discussed. The experimental analysis was carried out at the Towing Tank for Manoeuvres in Confined Water at Flanders Hydraulics Research (in co-operation with Ghent University). Model tests comprised a variation of different forward speeds, wave amplitudes and wave lengths (around one LPP). The water depth was fixed to a condition equivalent to a gross under keel clearance (UKC) of 100% of the ship’s draft.


Author(s):  
Jae-Hoon Lee ◽  
Yonghwan Kim ◽  
Min-Guk Seo

In the present study, the added resistance of a containership in parametric roll motion is investigated. The numerical simulation is carried out using a three dimensional Rankine panel method along with the weakly nonlinear formulation. The added resistance is evaluated by a near-field method, namely, the direct integration of the 2nd-order pressure on a body surface. To calculate the component resulting from the large-amplitude roll motion, the higher-order restoring and Froude-Krylov forces on wetted hull surfaces are taken into account. With or without parametric roll in regular waves, the components of added resistance classified with respect to integral terms are compared to figure out the important of each term. Through the investigation, the correlation between the added resistance and parametric roll is derived from coupling and decoupling the components of roll motion and vertical motions.


2007 ◽  
Vol 28 (4) ◽  
pp. 87-103 ◽  
Author(s):  
Christian Holden ◽  
Roberto Galeazzi ◽  
Claudio Rodríguez ◽  
Tristan Perez ◽  
Thor Inge Fossen ◽  
...  

2017 ◽  
Vol 144 ◽  
pp. 1-13 ◽  
Author(s):  
Jae-Hoon Lee ◽  
Yonghwan Kim

2015 ◽  
Vol 22 (3) ◽  
pp. 28-35
Author(s):  
Emre Peşman ◽  
Deniz Can Kolukısa ◽  
Metin Taylan

Abstract 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.


2016 ◽  
Vol 3 (1) ◽  
pp. 1235478
Author(s):  
Hamid Malekizade ◽  
Mohammad Reza Jahed-Motlagh ◽  
Bijan Moaveni ◽  
Ali Moarefianpour ◽  
Hassan Ghassemi

Author(s):  
Xian-Rui Hou ◽  
Zao-Jian Zou

Parametric roll resonance, as a nonlinear phenomenon related to ship stability, is particularly apt to happen when a ship is sailing in longitudinal waves. It can generate sudden oscillation with large amplitude up to 30–40 degrees of roll and put the ship and crew in danger. To predict the parametric roll resonance of ships, a suitable model for describing this phenomenon is needed. In this paper, a nonlinear mathematical model considering the strong nonlinear coupling among the heave, roll, and pitch motions of ships is established, and support vector regression (SVR) is applied to identify the unknown damping and restoring coefficients in the mathematical model. To verify the accuracy and validity of SVR in parametric identification, a container ship is considered, and the coupled heave, roll, and pitch motions of the ship in longitudinal regular waves are simulated. Based on the simulated responses, the unknown coefficients in the mathematical model are identified by SVR. Then the coupled heave-roll-pitch motion of the container ship in regular waves is predicted by using the identified coefficients in comparison with the simulated data, and satisfactory agreement is achieved. From this study, it is concluded that SVR can be applied to identify the unknown coefficients in the nonlinear mathematical model for predicting the parametric roll resonance of ships in longitudinal regular waves.


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