Influence of righting moment curve on parametric roll motion in regular longitudinal waves

2011 ◽  
pp. 135-141
Author(s):  
E Pesman ◽  
M Taylan
Keyword(s):  
Roll Motion ◽  
Parametric Roll ◽  
Moment Curve ◽  
Longitudinal Waves ◽  
Righting Moment

The Dynamics of Marine Vehicles With Inflectional Righting Moment Curves

1987 ◽  
Vol 109 (4) ◽  
pp. 335-344 ◽  
Author(s):  
M. H. Patel ◽  
J. A. Witz
Keyword(s):  
Frequency Domain ◽  
Numerical Solutions ◽  
Multiple Equilibrium ◽  
Roll Motion ◽  
Moment Curve ◽  
Marine Vehicles ◽  
Jump Phenomena ◽  
Righting Moment ◽  
Marine Vehicle ◽  
Fold Catastrophe

This paper investigates modifications to the dynamics of a marine vehicle caused by a point of inflection in its hydrostatic righting moment curve. Such inflections are shown to yield multiple equilibrium angles due to static over turning moments and to the occurrence of a classical fold catastrophe. Both frequency domain analyses and numerical solutions of the equation of roll motion are used to evaluate the influence of such inflections on the vessel’s dynamics. The analyses demonstrate that inflectional righting moment curves can yield unexpected roll amplitude jump phenomena close to resonance. The paper concludes with a discussion of the effects of such behavior on vessel hull designs.

Numerical Analysis of Added Resistance on Ship in Parametric Roll Motions

2016 ◽  
Author(s):  
Jae-Hoon Lee ◽  
Yonghwan Kim ◽  
Min-Guk Seo
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Field Method ◽  
Roll Motion ◽  
Added Resistance ◽  
Regular Waves ◽  
Nonlinear Formulation ◽  
Parametric Roll ◽  
Weakly Nonlinear ◽  
Rankine Panel Method

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.

Stability Analysis of an Initially Inclined Ship in Following Sea

2000 ◽  
Vol 67 (4) ◽  
pp. 717-719 ◽  
Author(s):  
S. K. Lee
Keyword(s):  
Computer Simulation ◽  
Stability Analysis ◽  
Longitudinal Wave ◽  
Roll Motion ◽  
Parametric Oscillation ◽  
Loss Of Stability ◽  
Longitudinal Waves ◽  
Analytic Expression ◽  
Ship Capsizing

Generally speaking, the causes of ship capsizing in waves are due to the pure loss of stability, parametric oscillation, and broaching-to phenomenon. In this paper, an analytic expression for the GZ value of a ship, inclined initially by some reasons like damage in longitudinal waves, is derived. And, the roll motion is calculated through the computer simulation to give the necessary information for the safe regions of various parameters of a ship moving in a longitudinal wave. [S0021-8936(00)00704-2]

Study on added resistance of a ship under parametric roll motion

2017 ◽  
Vol 144 ◽  
pp. 1-13 ◽  
Author(s):  
Jae-Hoon Lee ◽  
Yonghwan Kim
Keyword(s):  
Roll Motion ◽  
Added Resistance ◽  
Parametric Roll

scholarly journals Numerical and Analytical Approaches for Roll Motion Analysis in Regular Longitudinal Waves

2015 ◽  
Vol 22 (3) ◽  
pp. 28-35
Author(s):  
Emre Peşman ◽  
Deniz Can Kolukısa ◽  
Metin Taylan
Keyword(s):  
Motion Analysis ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Roll Motion ◽  
Diffraction Radiation ◽  
Parametric Roll ◽  
Stability And Bifurcations ◽  
Flow Theories ◽  
Analytical Approaches ◽  
Numerical Approaches

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.

Studies on parametric roll motion of ship under wave group by numerical simulation

2018 ◽  
Vol 163 ◽  
pp. 391-399 ◽  
Author(s):  
Liyuan Wang ◽  
Yougang Tang ◽  
Xiaorui Zhang ◽  
Jingchen Zhang
Keyword(s):  
Numerical Simulation ◽  
Roll Motion ◽  
Wave Group ◽  
Parametric Roll

Parametric Roll of High Speed Ships in Regular Waves

2013 ◽  
Author(s):  
Hisham Moideen ◽  
Abhilash Somayajula ◽  
Jeffrey M. Falzarano
Keyword(s):  
Time Domain ◽  
High Speed ◽  
Mathieu Equation ◽  
Analytical Models ◽  
Roll Motion ◽  
Regular Waves ◽  
Parametric Roll ◽  
Hull Form ◽  
Linear Damping ◽  
Metacentric Height

Analysis of ship parametric roll has generally been restricted to simple analytical models and sophisticated time domain simulations. Simple analytical models do not capture all the critical dynamics while time-domain simulations are often time consuming to implement. The model presented in this paper captures the essential dynamics of the system without over simplification. This work incorporates various important aspects of the system and assesses the significance of including or ignoring these aspects. Special consideration is given to the fact that a hull form asymmetric about the design waterline would not lead to a perfectly harmonic variation in metacentric height. Many of the previous works on parametric roll make the assumption of linearized and harmonic behavior of the time-varying restoring arm or metacentric height. This assumption enables modeling the roll motion as a Mathieu equation. This paper provides a critical assessment of this assumption and suggests modeling the roll motion as a Hills equation. Also the effects of non-linear damping are included to evaluate its effect on the bounded parametric roll amplitude in a simplified manner.

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