Green Water Assessment for Marine and Offshore Applications: Structural Response of the ULCS Breakwater

2018 ◽  
Author(s):  
Šime Malenica ◽  
Byung Hyuk Lee ◽  
Nikola Vladimir ◽  
Inno Gatin ◽  
Charles Monroy ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Structural Response ◽  
Green Water ◽  
Floating Body ◽  
Water Loading ◽  
Structure Interaction ◽  
Final Design ◽  
Numerical Tools ◽  
Large Container ◽  
Water Assessment

Green water loading which occurs during the floating body operations in heavy weathers can be very dangerous for the structural integrity of the superstructures and the equipment’s located at the upper decks. The correct modeling of the green water loading and the corresponding structural response is far from trivial and many different physical aspects need to be taken into account at the same time. Depending on the type of the floating body, the overall procedure involves the use of the different numerical tools at different steps. For off-shore type structures the procedure is slightly more complicated than for ships because, in addition to the classical seakeeping simulations, the mooring software also needs to be used. In all cases the final design conditions should be modeled using the complex hydro-structure interaction tools. In the present work the overall methodology is demonstrated and applied to the case of the evaluation of the structural response of the breakwater on the Ultra Large Container Ship (ULCS).

scholarly journals Fluid-Structure Interaction on The Design of Fully Assembled Shell Eco-Marathon (SEM) Prototype Car

CFD letters ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 115-136
Author(s):  
Hedy Soon Keey Tiew ◽  
Ming Wei Lee ◽  
Wei Shyang Chang ◽  
Mohammad Hafifi Hafiz Ishak ◽  
Farzad Ismail
Keyword(s):  
Structural Integrity ◽  
Fibre Composite ◽  
Fuel Efficiency ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Von Mises Stress ◽  
Fluid Structure ◽  
Structure Interaction ◽  
High Fuel Efficiency ◽  
Von Mises

To achieve high fuel efficiency, vehicles designs are inclined to choose lightweight materials and structures. However, these structures are generally weak, and structural integrity is a common concern. The purpose of this paper is to carry out fluid-structure interaction (FSI) study in one-way coupling analysis on a Shell Eco Marathon (SEM) prototype car which travels in a low-speed range to analyse its structural response. A new set of economical materials is proposed and analysed with the concern on self-fabrication process. The Flax fibre composite is introduced as a part of the proposed material set due to its environmental and economic advantages. The study herein is purely a numerical simulation work as a first approach to design a sustainable SEM prototype car. The fully assembled SEM prototype car was analysed with the proposed materials with ANSYS Workbench in the coupling of the fluid (ANSYS Fluent) and structural solver (ANSYS Mechanical) in a one-way FSI. Even with a thin shell design, the proposed material only experiences minimum deformations. The simulations also reveal that the maximum von-Mises stress experienced, after considered the safety factor, is still several order lower than the yield strength. This study has confirmed that the car design has fulfilled its structural requirements to operate at the design speed.

scholarly journals Structural Design Of Ultra Large Ships Based On Direct Calculation Approach

2016 ◽  
Vol Special edition (1) ◽  
pp. 53-79
Author(s):  
Nikola Vladimir ◽  
Ivo Senjanović ◽  
Šime Malenica ◽  
Jérôme De Lauzon ◽  
Hongil Im ◽  
...  
Keyword(s):  
Structural Design ◽  
Numerical Procedure ◽  
Structural Response ◽  
Direct Calculation ◽  
Theoretical Models ◽  
3D Fem ◽  
South Korean ◽  
Bulk Carriers ◽  
Numerical Tools ◽  
Large Container

The trend in modern sea transportation is building of ever larger ships, which require application of different direct calculation methodologies and numerical tools to achieve their reliable structural design. This is particularly emphasized in case of ultra large container ships (ULCS), but also other ship types like bulk carriers or large LNG ships belong to this category. In this context some classification societies have developed guidelines for performing direct calculations and for that purpose there are several hydro-structure tools available around the world, mainly relying on the same theoretical assumptions, but having incorporated different numerical procedures. Such tools are mostly based on the application of the 3D potential flow theoretical models coupled with the 3D FEM structural models. This paper illustrates application of general hydro-structure tool HOMER (BV) in the assessment of ship structural response in waves. An outline of the numerical procedure based on the modal approach is given together with basic software description. Application case is 19000 TEU ULCS built in South Korean shipyard Hyundai Heavy Industries. Extensive hydroelastic analyses of the ship are performed, and here some representative results for fatigue response with linear springing influence are listed.

A Study on the Whipping Phenomena Effect on the Structural Response of Large Container Ships

2018 ◽  
Vol 55 (4) ◽  
pp. 341-349 ◽  
Author(s):  
Beom-Il Kim ◽  
Min-Su Kim ◽  
Sun-Kee Seo ◽  
Jae-Hong Park
Keyword(s):  
Structural Response ◽  
Large Container

Fluid–Structure Interaction of High Aspect-Ratio Hair-Like Micro-Structures Through Dimensional Transformation Using Lattice Boltzmann Method

2016 ◽  
Vol 08 (08) ◽  
pp. 1650095 ◽  
Author(s):  
H. Devaraj ◽  
Kean C. Aw ◽  
E. Haemmerle ◽  
R. Sharma
Keyword(s):  
Fluid Flow ◽  
Drag Force ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Momentum Exchange ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Micro Structures

3D printed hair-like micro-structures have been previously demonstrated in a novel micro-fluidic flow sensor aimed at sensing air flows down to rates of a few milliliters per second. However, there is a lack of in-depth understanding of the structural response of these ‘micro-hairs' under a fluid flow field. This paper demonstrates the use of lattice Boltzmann methods (LBM) to understand this structural response towards a better optimization of the micro-hair flow sensors designed to suit the end applications' needs. The LBM approach was chosen as an efficient alternative to simulate Navier–Stokes equations for modeling fluid flow around complex geometries primarily for improved accuracy and simplicity with lesser computational costs. As the spatial dimensions of the sensor's flow channel are much larger in comparison to the actual micro-hairs (the sensing element), a multidimensional approach of combining two-dimensional (D2Q9) and three-dimensional (D3Q19) lattice configurations were implemented for improved computational speeds and efficiency. The drag force on the micro-hairs was estimated using the momentum-exchange method in the D3Q19 configuration and this drag force is transferred to the structural analysis model which determines the micro-hair deformation using Euler–Bernoulli beam theory. The entirety of the LBM Fluid–Structure Interaction (FSI) model was implemented within MATLAB and the obtained results are compared against the numerical model implemented on a commercially available software package.

Numerical Research on FPSOs With Green Water Occurrence

2009 ◽  
Vol 53 (01) ◽  
pp. 7-18
Author(s):  
Renchuan Zhu ◽  
Guoping Miao ◽  
Zhaowei Lin
Keyword(s):  
Three Dimensional ◽  
Green Water ◽  
Floating Body ◽  
Incoming Wave ◽  
Model Case ◽  
Floating Structures ◽  
Design And Optimization ◽  
Head Waves ◽  
Wave Heights ◽  
The Impact

Green water loads on sailing ships or floating structures occur when an incoming wave significantly exceeds freeboard and water runs onto the deck. In this paper, numerical programs developed based on the platform of the commercial software Fluent were used to numerically model green water occurrence on floating structures exposed to waves. The phenomena of the fixed floating production, storage, and offloading unit (FPSO) model and oscillating vessels in head waves have been simulated and analyzed. For the oscillating floating body case, a combination idea is presented in which the motions of the FPSO are calculated by the potential theory in advance and computional fluid dynamics (CFD) tools are used to investigate the details of green water. A technique of dynamic mesh is introduced in a numerical wave tank to simulate the green water occurrence on the oscillating vessels in waves. Numerical results agree well with the corresponding experimental results regarding the wave heights on deck and green water impact loads; the two-dimensional fixed FPSO model case conducted by Greco (2001), and the three-dimensional oscillating vessel cases by Buchner (2002), respectively. The research presented here indicates that the present numerical scheme and method can be used to actually simulate the phenomenon of green water on deck, and to predict and analyze the impact forces on floating structures due to green water. This can be of great significance in further guiding ship design and optimization, especially in the strength design of ship bows.

scholarly journals ARMOUR UNIT STRUCTURAL RESPONSE - A PARAMETRIC STUDY

1988 ◽  
Vol 1 (21) ◽  
pp. 176
Author(s):  
C. David Anglin ◽  
William F. Baird ◽  
Etienne P.D. Mansard ◽  
R. Douglas Scott ◽  
David J. Turcke
Keyword(s):  
Wave Height ◽  
Parametric Study ◽  
Structural Integrity ◽  
Design Procedure ◽  
Structural Response ◽  
Design Parameters ◽  
Coastal Structures ◽  
Log Normal ◽  
Wave Induced ◽  
Hydraulic Stability

There is a general lack of knowledge regarding the nature and magnitude of loads acting on armour units used for the protection of rubblemound coastal structures. Thus, a comprehensive design procedure incorporating both the hydraulic stability and the structural integrity of the armour units does not exist. This paper presents the results of a detailed parametric study of the structural response of armour units to wave-induced loading in a physical breakwater model. The effect of the following design parameters is investigated: breakwater slope, armour unit location, wave period and wave height. This research has made a number of significant contributions towards the development of a comprehensive design procedure for concrete armour units. It has identified a linear relationship between the wave-induced stress in the armour units and the incident wave height. In addition, it has shown that the conditional probability of waveinduced stress given wave height can be estimated by a log-normal distribution. Finally, a preliminary design chart has been developed which incorporates both the structural integrity and the hydraulic stability of the armour units.

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