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An energy analysis of parametric roll for application to the second generation intact stability criteria

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Abstract

Parametric roll is an amplification of the roll motion due to the periodic variation of the restoring moment in waves. This phenomenon is mostly observed in head and following seas and is the cause of several accidents occurred on container vessels during recent decades. One of the second generation intact stability criteria, currently under finalization and validation by the IMO, requires computing the maximum roll angle with regard to parametric roll. Both proposed methods are relatively complex to implement and require tools that naval architects are not accustomed to. In this paper, we propose an easier alternative method providing the amplitude of parametric roll for any loading condition at any speed, based on energy considerations and assuming a linear GZ. The implementation of this easy method in the corresponding second generation intact stability criterion provides almost the same value of KGmax than the on-degree-of-freedom time simulation proposed by the future regulation.

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... Cavitation generally incepts when the local pressure drops below the saturated vapor pressure, and phase change occurs; ventilation usually incepts when the local pressure drops below the pressure of an impinging non-condensable gas (such as air from the atmosphere) and when a continuous path of ingress is available [26]. Parametric resonance can also occur in waves because the hydrodynamic restoring force coefficients change with vessel motions, and this is called parametric roll [27]. Another potential issue is modal coalescence when the system modal frequencies become coincident as a result of mass and/or stiffness changes to the system. ...
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Development of second generation intact stability criteria. US Navy, Naval Surface Warfare Center Carderock Division
  • V Belenky
  • C Bassler
  • K Spyrou
Stability and safety of ships
  • V Belenky
  • N B Sevastianov
Development of analytical nonlinear models for parametric roll and hydrostatic restoring variations in regular and irregular waves
  • G Bulian
Different computations of parametric roll Level 2 criterion
  • F Grinnaert
  • J-Y Billard
Advanced dynamics of marine structures
  • J Hooft