Effect of freeboard and metacentric height on capsizing probability of purse seiners in irregular beam seas

2007 ◽  
Vol 12 (3) ◽  
pp. 150-159 ◽  
Author(s):  
Daeng Paroka ◽  
Naoya Umeda
Keyword(s):  
Beam Seas ◽  
Capsizing Probability ◽  
Metacentric Height ◽  
Irregular Beam Seas

Effect of Hydrodynamic Memory on Ship Capsizing in Irregular Beam Wind and Waves

2017 ◽  
Author(s):  
Hiroki Yoshizumi ◽  
Takashi Tsuji ◽  
Naoya Umeda ◽  
Atsuo Maki
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Radiation Force ◽  
Stability Criteria ◽  
Beam Seas ◽  
Intact Stability ◽  
Capsizing Probability ◽  
Criterion Development ◽  
Dead Ship Condition ◽  
Harmonic Resonance

For examining a numerical simulation model for the IMO (International Maritime Organization) second generation intact stability criteria for dead ship condition, capsizing probability of a ship in random beam wind and waves was estimated by the model experiments and is compared with that estimated with numerical simulation using a coupled roll model (sway-heave-roll-pitch) to be used for new stability criterion development for dead ship stability. By using the memory effect function to calculate radiation force, the simulation model is well validated in capsizing probability with the existing model experiment of a ship suffering harmonic resonance. However, the simulation model fails to estimate the case of a large passenger ship which suffers parametric resonance in beam seas.

Experimental and Numerical Study of the Slow-Drift Motion of a Rectangular Barge Moored at an Inclined Beach

2010 ◽  
Author(s):  
Bernard Molin ◽  
Fabien Remy ◽  
Yanan Liu ◽  
Marie-Christine Rouault
Keyword(s):  
Numerical Study ◽  
Scale Model ◽  
Sea State ◽  
Flat Bottom ◽  
Drift Motion ◽  
Beam Seas ◽  
Slow Drift ◽  
Irregular Beam Seas ◽  
Sway Motion ◽  
Slow Drift Motion

An experimental campaign is reported on the slow-drift motion of a rectangular barge moored in irregular beam seas. The 24 m long false bottom of the basin is raised and inclined at a slope of 5%, from 1.05 m below the free surface to 0.15 m above. The barge is moored successively at 4 different locations, in water-depths ranging from 54 to 21 cm. The measured slow-drift component of the sway motion is compared with state-of-the-art calculations based on Newman approximation. At 54 cm depth good agreement is obtained between calculations and measurements. At 21 cm depth the Newman calculation exceeds the measured value. When the flat bottom setdown contribution is added up, the calculated value is 2 to 3 times larger than the measured one. A second-order model is proposed to account for the shoaling of a bichromatic sea-state propagating in decreasing water-depth. Application of this numerical model to the scale-model tests shows that in shoaling conditions the setdown contribution to the slow-drift excitation can counteract and not necessarily add up to the Newman component.

Theoretical determination of asymmetric rolling amplitude in irregular beam seas

2021 ◽  
Author(s):  
Atsuo Maki ◽  
Leo Dostal ◽  
Yuuki Maruyama ◽  
Masahiro Sakai ◽  
Toru Katayama ◽  
...  
Keyword(s):  
Asymmetric Rolling ◽  
Theoretical Determination ◽  
Beam Seas ◽  
Irregular Beam Seas
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