Computation of Fully Nonlinear Wave Loads on a Large Container Ship by CIP Based Cartesian Grid Method

2010 ◽  
Author(s):  
Changhong Hu ◽  
Makoto Sueyoshi ◽  
Ryuji Miyake ◽  
Tingyao Zhu
Keyword(s):  
Nonlinear Wave ◽  
Cross Sections ◽  
Grid Method ◽  
Cartesian Grid ◽  
Ship Motions ◽  
Container Ship ◽  
Wave Loads ◽  
Response Characteristics ◽  
Cartesian Grid Method ◽  
Large Container

A Cartesian grid method with CIP (Constraint Interpolation Profile [1]) based flow solver has been developed and applied to many strongly nonlinear free surface problems. In this paper we present a research on applying the method to predict nonlinear wave loads on a container ship, which is advancing at a constant forward speed in regular waves with large amplitudes. Numerical computations are carried out on a head sea case and a bow sea case. The computed frequency response characteristics for the ship motions and the wave loads including vertical bending moments on the cross-sections and hydrodynamic pressures on the hull, are compared to a model test result and the result obtained by two potential flow based numerical methods. The nonlinear features of the numerical results are discussed.

Extreme Value Statistics of Large Container Ship Roll

2016 ◽  
Vol 60 (02) ◽  
pp. 92-100
Author(s):  
Oleg Gaidai ◽  
Gaute Storhaug ◽  
Arvid Naess
Keyword(s):  
Nonlinear Behavior ◽  
Extreme Value Statistics ◽  
Ship Motions ◽  
Primary Concern ◽  
Container Ship ◽  
Highly Nonlinear ◽  
Extreme Response ◽  
Measured Time ◽  
Time Histories ◽  
Large Container

The paper describes a method for prediction of large container ship extreme roll angles occurring during sailing in harsh weather. Rolling is coupled with other ship motions and exhibits highly nonlinear behavior. Risk of losing containers due to a large roll is primary concern for ship transport. Because of non-stationarity and complicated nonlinearities of both waves and ship motions, it is a considerable challenge to model such a phenomenon. In case of extreme motions, the role of nonlinearities dramatically increases, activating effects of second and higher order. Moreover, laboratory tests may also be questioned because of the scaling and the sea state choice. Therefore, data measured on actual ships during their voyages in harsh weather provide a unique insight into statistics of ship motions. The aim of this work is to benchmark state of art method, which makes it possible to extract the necessary information about the extreme response from onboard measured time histories. The method proposed in this paper opens up the possibility to predict simply and efficiently both short- and long-term extreme response statistics.

Cartesian Grid Method for Moderate-Reynolds-Number Flows Around Complex Moving Objects

AIAA Journal ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Jo-Einar Emblemsvag ◽  
Ryuta Suzuki ◽  
Graham V. Candler
Keyword(s):  
Reynolds Number ◽  
Moving Objects ◽  
Grid Method ◽  
Cartesian Grid ◽  
Cartesian Grid Method ◽  
Moderate Reynolds Number ◽  
Reynolds Number Flows

Development of Cooling Structures for Blu-Ray Disc Compatible Optical Disc Drives Using Computational Fluid Dynamics Based on Cartesian Grid Method

2007 ◽  
Author(s):  
Nobuyuki Isoshima ◽  
Takayuki Fujimoto ◽  
Yukinobu Abe ◽  
Masatoshi Watanabe ◽  
Yoshiaki Yamauchi ◽  
...  
Keyword(s):  
Laser Diode ◽  
High Speed ◽  
High Performance ◽  
Flow Simulation ◽  
Grid Method ◽  
Ambient Air ◽  
Cartesian Grid ◽  
Optical Disc ◽  
Rotating Disc ◽  
Cartesian Grid Method

High-performance, simple cooling structures for optical disc drives compatible with the Blu-ray disc (BD) were developed using unsteady numerical flow simulation based on the Cartesian grid method. In the new structure, an additional hole in the tray outside of the disc induced a secondary upward flow, which is caused by a pressure difference and rotating-disc flow. The secondary flow decreases the ambient air-temperature of the laser diode below the hole, and furthermore it increases the velocity around the laser diode and enhances the heat transfer rate. The experimental results indicate that the cooling effect of the laser diode increases, and the disc vibration is not influenced by the additional hole in the tray. The cooling structures are applied to the so-called super-multi BD drive, which achieved 4X high-speed recording for the first time in the industry.

Time Domain Analysis of Springing and Whipping Responses Acting on a Large Container Ship

2011 ◽  
Author(s):  
Yongwon Lee ◽  
Zhenhong Wang ◽  
Nigel White ◽  
Spyros E. Hirdaris
Keyword(s):  
Time Domain ◽  
Nonlinear Effects ◽  
Time Domain Analysis ◽  
Container Ship ◽  
Wave Loads ◽  
Ocean Engineering ◽  
Hull Girder ◽  
Engineering Research ◽  
Large Container ◽  
Element Method

As part of WILS II (Wave Induced Loads on Ships) Joint Industry Project organised by MOERI (Maritime and Ocean Engineering Research Institute, Korea), Lloyd’s Register has undertaken time domain springing and whipping analyses for a 10,000 TEU class container ship using computational tools developed in the Co-operative Research Ships (CRS) JIP [1]. For idealising the ship and handling the flexible modes of the structure, a boundary element method and a finite element method are employed for coupling fluid and structure domain problems respectively. The hydrodynamic module takes into account nonlinear effects of Froude-Krylov and restoring forces. This Fluid Structure Interaction (FSI) model is also coupled with slamming loads to predict wave loads due to whipping effects. Vibration modes and natural frequencies of the ship hull girder are calculated by idealising the ship structure as a Timoshenko beam. The results from springing and whipping analyses are compared with the results from linear and nonlinear time domain calculations for the rigid body. The results from the computational analyses in regular waves have been correlated with those from model tests undertaken by MOERI. Further the global effects of springing and whipping acting on large container ships are summarised and discussed.

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