scholarly journals EVALUATING THE METACENTRIC HEIGHT OF CONTAINER SHIP INFLUENCE ON GENERATION OF CONDITIONS CONTRIBUTING TO THE OCCURRENCE OF PARAMETRIC ROLLING RESONANCE

2021 ◽  
Vol 13 (3) ◽  
pp. 359-371
Author(s):  
Ruslan Stanislavovich Tsarik ◽  
Keyword(s):  
Container Ship ◽  
Parametric Rolling ◽  
Metacentric Height

Parametric Rolling in Regular Head Waves of the KRISO Container Ship: Numerical and Experimental Investigation in Shallow Water

2019 ◽  
Author(s):  
Manases Tello Ruiz ◽  
Jose Villagomez ◽  
Guillaume Delefortrie ◽  
Evert Lataire ◽  
Marc Vantorre
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Water Waves ◽  
Failure Modes ◽  
Container Ship ◽  
Parametric Roll ◽  
Parametric Rolling ◽  
Wave Characteristics ◽  
Intact Stability ◽  
Head Waves

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.

Numerical Investigation of Parametric Rolling of a Container Ship in Regular and Irregular Waves

2017 ◽  
Author(s):  
Suresh Rajendran ◽  
C. Guedes Soares
Keyword(s):  
Incident Wave ◽  
Radiation Force ◽  
Wave Profile ◽  
Irregular Waves ◽  
Container Ship ◽  
Hydrodynamic Coefficients ◽  
Parametric Rolling ◽  
Nonlinear Radiation ◽  
Strip Theory ◽  
Radiation Forces

Parametric rolling of a post-Panamax C11 class containership in regular and irregular waves is numerically investigated using body nonlinear time domain methods based on strip theory. The Froude-Krylov and the hydrostatic forces are calculated for the exact wetted surface area under the undisturbed incident wave profile. Two kinds of formulations are used for calculation of the radiation forces. The first one employs a linear radiation force in which the frequency dependent hydrodynamic coefficients are calculated for mean position of the sections at mean water level. The second formulation calculates the hydrodynamic coefficients for the exact submerged depth of ship sections under the undisturbed incident wave profile, and hence called as body nonlinear radiation force. The numerical results from the aforementioned formulations are compared with each other, and also with experimental results obtained from a wave tank in both regular and irregular waves. For all the cases in regular waves, the vulnerability to parametric rolling is clearly identified by the numerical models, even though a few discrepancies are observed in the estimation of the severity (maximum roll angle) of the problem. In this paper, the effects of the linear and body nonlinear radiation forces on the numerical calculation of parametric rolling of a container ship and the ability of the numerical methods to identify parametric rolling are investigated.

scholarly journals Influence of four modern Flettner rotors, used as wind energy capturing system, on container ship stability

2020 ◽  
Vol 180 ◽  
pp. 02003
Author(s):  
Mihail-Vlad Vasilescu ◽  
Ionut Voicu ◽  
Cornel Panait ◽  
Violeta-Vali Ciucur
Keyword(s):  
Wind Energy ◽  
Container Ship ◽  
Ship Stability ◽  
Longitudinal Stability ◽  
Stability Calculation ◽  
Power Generators ◽  
The Stability ◽  
Metacentric Height

This article is presenting the influence on the stability of a container ship, by connecting four modern Flettner rotors, as wind energy capturing system. Modern Flettner rotors, are energy power generators. They are one of the various equipment used to capture and harness wind energy. By reading the article, the reader can discover what are the forces which influence the modern Flettner rotors and how they influence the ship stability.This article major points are: calculation the influence of the modern Flettner rotors on the ship transverse and longitudinal stability, calculation of the ship new displacement, new draft, new metacentric height and period of rolling.

Application of Volterra Series Analysis for Parametric Rolling in Irregular Seas

2014 ◽  
Vol 58 (02) ◽  
pp. 97-105
Author(s):  
Hisham Moideen ◽  
Abhilash Somayajula ◽  
Jeffrey M. Falzarano
Keyword(s):  
Volterra Series ◽  
Irregular Waves ◽  
Parametric Roll ◽  
Peak Period ◽  
Parametric Rolling ◽  
Motion Sensitivity ◽  
Direct Excitation ◽  
Head Waves ◽  
Metacentric Height ◽  
Regular Head Waves

Parametric roll is a phenomenon in which there is a large rolling motion of a ship even when the ship is moving into head seas with no direct excitation. It is a nonlinear dynamic phenomenon of a ship rolling system with nonlinearities in the stiffness as well as the damping terms. Parametric roll of container ships in head seas is a relatively new problem, which has gained lot of importance after the catastrophic incidence of APL China in 1998. Analysis of parametric roll of container ships in regular head waves has been studied extensively. However, the ships do not encounter regular waves in the ocean. So, it is necessary to study how important parametric roll is in irregular seas. To study this, it is first important to model the variation of metacentric height in irregular waves, which is nonlinear as a result of the influence of underwater geometry and the motions of the ship in a seaway. In this work, the change of metacentric height (GM) in irregular waves has been modeled using a Volterra series approach. This transfer function for metacentric height (GM) is used to study parametric rolling of ships in irregular waves. Based on this study, roll motion sensitivity to the spectral peak period and significant wave height has been carried out.

Numerical Simulations of KCS Parametric Rolling in Head Waves

2019 ◽  
Author(s):  
Shuang Wang ◽  
Junkai Wei ◽  
Xuanshu Chen ◽  
Liwei Liu ◽  
Zhiguo Zhang
Keyword(s):  
Failure Modes ◽  
Coupling Effect ◽  
Simulation Method ◽  
Rolling Motion ◽  
Stochastic Dynamic ◽  
Container Ship ◽  
Parametric Rolling ◽  
Ship Model ◽  
Head Waves ◽  
Wetted Area

Abstract As a type of the ship stability failure modes, parametric rolling has attracted more attention from many researchers in recent years because of a series of accidents due to ship instability, especially the instability of container ship. Parametric rolling is a complex nonlinear stochastic dynamic problem, which is often accompanied by large amplitude vertical motions of ships. At present, there are many difficulties in the research of ship parameter rolling, mainly including the nonlinearity of parameter rolling motion, the random variation of wetted area of the hull surface up to the incident wave waterline and the coupling effect of rolling, pitching and heaving. Nowadays, the potential flow theory is a common method to predict parametric rolling, but this method may generate results with low accuracy in some conditions. This paper describes a numerical simulation method based on in-house CFD code HUST-Ship to analyze parametric rolling motion of KCS (KRISO Container Ship) container ship model. The paper studies the occurring conditions of parametric rolling motion of KCS model and reveals the mechanism of parametric rolling.

Numerical Prediction and Experimental Validation of Slamming Load for Large Container Ship Undergoing Parametric Rolling Motion

2018 ◽  
Author(s):  
Yuan Lin ◽  
Ning Ma ◽  
Deyu Wang ◽  
Xiechong Gu
Keyword(s):  
Domain Model ◽  
Roll Motion ◽  
Container Ship ◽  
Occurrence Probability ◽  
Wave Condition ◽  
Parametric Rolling ◽  
Rolling Condition ◽  
Slamming Load ◽  
Large Container ◽  
Flare Slamming

This article proposes an approximate prediction method for slamming loads in parametric rolling condition for large container ships and the method has been validated through model experiments. Up to now, there have been some studies focused on two-dimensional asymmetric slamming analysis. Nevertheless, slamming load prediction in parametric rolling condition should consider not only heave and pitch motions, but also large amplitude roll motion which is usually neglected in analysis. For this purpose, a 6-DOF weakly nonlinear time domain model is adopted to predict the ship motions including parametric roll motion. The consequent roll motions obtained by the proposed model are incorporated in the calculation of impact angle and relative vertical velocity between ship section on the bow flare and wave surface, according to an asymmetric water entry assumption. Slamming impact loads and occurrence probability of slamming are analyzed by the Wagner model. To validate the numerical method, the segmented model experiment of a 10000 TEU container ship was executed and the slamming impact pressures and bending moments were measured for the wave condition and ship forward speed. The calculated pressures are compared with experiments. Based on numerical simulations, the maximum flare slamming pressures and slamming occurrence probability in different speed and wave conditions are investigated. The results indicate that flare slamming pressure is smaller than bottom slamming, but possessing longer lasting time and the occurrence of flare slamming is associated with the cycles of parametric rolling motions. Furthermore, the relationship between slamming pressure and 3-DOF motions namely roll, pitch and heave in the simultaneous simulation is given and the mechanism of flare slamming phenomena in parametric rolling condition is elaborated.

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