Experimental Study on Wave Loads of Flooded Ship

2007 ◽  
Author(s):  
B. W. Kim ◽  
D. C. Hong ◽  
S. Y. Hong ◽  
J. H. Kyoung ◽  
S. K. Cho ◽  
...  
Keyword(s):  
Model Test ◽  
Ship Motions ◽  
Test Model ◽  
Bending Moments ◽  
Wave Loads ◽  
Test Results ◽  
Ocean Engineering ◽  
Shear Forces ◽  
Engineering Research ◽  
Ship Model

This paper investigates wave loads of a flooded ship by model test. Model tests are performed in ocean engineering basin of MOERI (Maritime and Ocean Engineering Research Institute). Ship motions are measured by RODYM6D. Wave loads such as shear forces, bending moments and torsion moments are measured by ATI load cell mounted on segmented parts of the ship model. A 300 m-long barge ship with two flooded compartments is considered in model test. Responses of intact and flooded cases are compared. The test results are also compared with numerical analyses using boundary element method.

EFD and CFD Study of Forces, Ship Motions, and Flow Field for KRISO Container Ship Model in Waves

2020 ◽  
Vol 64 (01) ◽  
pp. 61-80
Author(s):  
Ping-Chen Wu ◽  
Md. Alfaz Hossain ◽  
Naoki Kawakami ◽  
Kento Tamaki ◽  
Htike Aung Kyaw ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Flow Field ◽  
Flow Simulation ◽  
Wake Flow ◽  
Ship Motions ◽  
Container Ship ◽  
Added Resistance ◽  
Ocean Engineering ◽  
Ship Model ◽  
Calm Water

Ship motion responses and added resistance in waves have been predicted by a wide variety of computational tools. However, validation of the computational flow field still remains a challenge. In the previous study, the flow field around the Korea Research Institute for Ships and Ocean Engineering (KRISO) Very Large Crude-oil Carrier 2 tanker model with and without propeller condition and without rudder condition was measured by the authors, as well as the resistance and self-propulsion tests in waves. In this study, the KRISO container ship model appended with a rudder was used for the higher Froude number .26 and smaller block coefficient .65. The experiments were conducted in the Osaka University towing tank using a 3.2-m-long ship model for resistance and self-propulsion tests in waves. Viscous flow simulation was performed by using CFDShip-Iowa. The wave conditions proposed in Computational Fluid Dynamics (CFD) Workshop 2015 were considered, i.e., the wave-ship length ratio λ/L = .65, .85, 1.15, 1.37, 1.95, and calm water. The objective of this study was to validate CFD results by Experimental Fluid Dynamics (EFD) data for ship vertical motions, added resistance, and wake flow field. The detailed flow field for nominal wake and self-propulsion condition will be analyzed for λ/L = .65, 1.15, 1.37, and calm water. Furthermore, bilge vortex movement and boundary layer development on propeller plane, propeller thrust, and wake factor oscillation in waves will be studied.

Springing Responses Analysis and Segmented Model Testing on a 550,000 DWT Ore Carrier

2016 ◽  
Author(s):  
Hui Li ◽  
Di Wang ◽  
Cheng Ming Zhou ◽  
Kaihong Zhang ◽  
Huilong Ren
Keyword(s):  
Natural Frequency ◽  
Design Stage ◽  
Resonant Vibration ◽  
Bending Moments ◽  
Wave Loads ◽  
Regular Waves ◽  
Segmented Model ◽  
Ship Model ◽  
Hull Structure ◽  
Stiffness Distribution

For ultra large ore carriers, springing response should be analyzed in the design stage since springing is the steady-state resonant vibration and has an important effect on the fatigue strength of hull structure. The springing response of a 550,000 DWT ultra large ore carrier has been studied by using experimental and numerical methods. A flexible ship model composed of nine segments was used in the experiment. The model segments were connected by a backbone with varying section, which can satisfy the request of natural frequency and stiffness distribution. The experiments in regular waves were performed and the motions and wave loads of the ship were measured. The experimental results showed that springing could be excited when the wave encounter frequency coincides with half or one-third the flexural natural frequency of the ship. In this paper, the analysis of the hydroelastic responses of the ultra large ore carrier was also carried out using a 3-D hydroelastic method. Comparisons between experimental and numerical results showed that the 3-D hydroelastic method could predict the motions and the vertical bending moments quite well. Based on this numerical method, the fatigue damage was estimated and the contribution of springing was analyzed.

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.

The Investigation of Non-Linear Effect for a Circular Cylinder Shaped FPSO

2011 ◽  
Author(s):  
Sam-Kwon Hong ◽  
Rae-Hyoung Yuck ◽  
Beom-Seon Jang ◽  
Hi-Seok Kang ◽  
Se-Eun Kim ◽  
...  
Keyword(s):  
Circular Cylinder ◽  
Model Test ◽  
Ocean Waves ◽  
Ocean Engineering ◽  
Natural Period ◽  
Pitch Motion ◽  
Steel Catenary Riser ◽  
Engineering Research ◽  
Motion Performance ◽  
Plane Area

Nowadays, a circular cylinder shaped FPSO appears as a new type FPSO because it does not need the expensive turret system. A circular cylinder shaped FPSO has an excellent motion performance because pitch and roll natural periods are longer compared to traditional FPSO and heave natural period is also longer due to its small water plane area. Samsung heavy industries has developed a circular cylinder shaped FPSO called as S-Line. The feature of S-line has a shape cutting a groove around draft to reduce the water plane area. Through reducing water plane area, the heave natural frequency moves to lower frequency which is far from ocean waves. According to the results of a linear calculation by WAMIT, S-Line showed reduced vertical motion of heave, roll and pitch compared to conventional FPSO. But, S-Line showed unsuspected large pitch response in 1st model test which was carried out with horizontal mooring system by spring in SSMB (Samsung Ship Model Basin). It is conjectured that this large pitch response is caused by 2nd nonlinearity of the wave and/or parametric pitch phenomena. To verify the mooring load and improve the 2nd order pitch motion, model tests were carried out in SSMB and offshore basin of MOERI (Maritime & Ocean Engineering Research Institute) with two kinds of bilge box. This paper describes the nonlinear effect of 2nd order for pitch motion of a circular cylinder shaped FPSO based on model test and numerical simulation. As a result, S-Line developed by Samsung was also verified being able to use SCR (Steel Catenary Riser) due to its improved heave motion performance.

Experimental Investigation of Wave Loads Based on Trimaran Self-Propulsion Model

2016 ◽  
Author(s):  
Wei Xiaobo ◽  
Huilong Ren ◽  
Yanlong Sun ◽  
Di Wang ◽  
Zhen Yu Wang
Keyword(s):  
Model Test ◽  
High Speed ◽  
High Performance ◽  
Similarity Theory ◽  
Scale Model ◽  
Comprehensive Model ◽  
Wave Loads ◽  
Test Results ◽  
Regular Waves ◽  
Test Study

Trimaran, as a high performance ship, its special ship form is different from regular monohull ship. The particular characteristics of longitudinal and transverse wave loads are concerned greatly by ship structure designers. Theoretical methods for forecasting the wave loads of trimaran are under developing. And the relative comprehensive model test study of trimaran’s wave loads is rare in the publication. In this paper, the trimaran model test had been carried out in the tank. According to similarity theory and simulation of stiffness, a scale model of trimaran with measurement system had been manufactured. Then the segmented model had navigated in regular waves of different sea conditions. Through analysis of the experimental data, the wave loads characteristics of this trimaran are presented. A comparison of test results and theoretical values is also made to show the similarities and differences. This study can provide some useful information for further design of high-speed trimaran in the point of wave loads, which maybe a reference for research of trimaran.

Model Test of an Ice Class Bulk Carrier With the Thyssen/Waas Bow Form

1986 ◽  
Vol 108 (2) ◽  
pp. 168-172 ◽  
Author(s):  
A. Freitas ◽  
R. S. Nishizaki
Keyword(s):  
Northwest Territories ◽  
Model Test ◽  
Canadian Arctic ◽  
Scale Model ◽  
Test Results ◽  
Bulk Carrier ◽  
Test Program ◽  
Conventional Form ◽  
Ship Model ◽  
Transportation Development

Alternative bow forms have been investigated for the “M. V. Arctic” in a test program sponsored by the German Ministry for Research and Technology and the Transportation Development Centre of Transport Canada. The “M. V. Arctic” is a Canadian Arctic Class 2 bulk carrier of 28000 dwt which operates between the Northwest Territories and Europe during the summer and fall months. The tests were conducted at the Hamburg Ship Model Basin using a 1/30th scale model fitted with three different forebody forms. These included the Thyssen/Waas design, a new design by Melville Shipping Ltd., Calgary, and the existing bow form. The tests were performed in ice, still water and irregular seaway. The Thyssen/Waas icebreaker system includes a novel bow form and employs an unconventional icebreaking technique. The system has been successfully tested in model and demonstrated in full scale with the modified icebreaker “Max Waldeck”. The Melville design uses a conventional form incorporating the latest technology. This paper describes the model tests and discusses the relative performance as indicated by the test results. The investigation has shown the potential for the use of the Thyssen/Waas bow form on icebreaking cargoships such as the “M.V. Arctic”.

scholarly journals Experimental study on dynamic effect of freestanding tower of sea-crossing bridge under wave load

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Zhou Daocheng ◽  
Zhang Bo ◽  
Xue Sisi ◽  
Wei Chengxun ◽  
Ou Jinping
Keyword(s):  
Experimental Study ◽  
Dynamic Effect ◽  
Pile Group ◽  
Test Model ◽  
Wave Loads ◽  
Test Results ◽  
Base Shear ◽  
Wave Load ◽  
Vibration Period ◽  
Bridge Tower

AbstractThere is a debate over whether the sea-crossing bridges undergo dynamic motions when exposed to wave loads. In order to verify the dynamic effect of the tower of sea-crossing bridge under wave load, an experimental study on dynamic effect of a freestanding tower of sea-crossing bridge is accomplished in this paper. Firstly, a test model for a typical bridge tower of pile group foundation under wave load is established by using a scale of 1:100. Secondly, a typical sea condition is designed for the response test of the bridge tower under wave load. The test results indicated that obvious vibration of top the tower occurs when the wave load period is close to the natural vibration period of the structure, and both displacement and base shear are amplified. The results in this paper will provide an important reference for whether the dynamic effect of wave load should be considered in the designs of bridge structure under wave load.

scholarly journals Method for Prediction of Extreme Wave Loads Based on Ship Operability Analysis Using Hindcast Wave Database

2021 ◽  
Vol 9 (9) ◽  
pp. 1002
Author(s):  
Tamara Petranović ◽  
Antonio Mikulić ◽  
Marko Katalinić ◽  
Maro Ćorak ◽  
Joško Parunov
Keyword(s):  
Transfer Functions ◽  
Extreme Values ◽  
Bending Moment ◽  
Ship Motions ◽  
Bending Moments ◽  
Wave Loads ◽  
Extreme Wave ◽  
Short Term ◽  
Passenger Ship ◽  
Limiting Values

The method for the prediction of extreme vertical wave bending moments on a passenger ship based on the hindcast database along the shipping route is presented. Operability analysis is performed to identify sea states when the ship is not able to normally operate and which are likely to be avoided. Closed-form expressions are used for the calculation of transfer functions of ship motions and loads. Multiple operability criteria are used and compared to the corresponding limiting values. The most probable extreme wave bending moments for the short-term sea states at discrete locations along the shipping route are calculated, and annual maximum extreme values are determined. Gumbel probability distribution is then fitted to the annual extreme values, and wave bending moments corresponding to a return period of 20 years are determined for discrete locations. The system reliability approach is used to calculate combined extreme vertical wave bending moment along the shipping route. The method is employed on the example of a passenger ship sailing across the Adriatic Sea (Split, Croatia, to Ancona, Italy). The contribution of the study is the method for the extreme values of wave loads using the hindcast wave database and accounting for ship operational restrictions.

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