Strength Analysis of Oil Tanker Under Numerical Wave

Author(s):  
Cheng Shu ◽  
Li Hong ◽  
Zhang Dongxu

The strength of an oil carrier is generally checked using static load or equivalent load of wave action in accordance with relevant specifications. In order to accurately calculate the stress and the deformation of an oil carrier under wave action, the fluid-structure interaction system in the platform Workbench is used in this work. And, the pressure-based solver, the two-phase flow model and UDF (User Defined Function) in the software FLUENT are used to compile the three-order Stokes Wave so as to simulate ocean waves. Forces acting on the surface of the oil carrier are obtained by calculating the flow field, and the structural strength of the carrier is then investigated under sagging and hogging conditions. The results show that: the three-order Stokes Wave matches well with the theoretical result, and it is feasible to research the strength of the oil carrier by generating waves using this numerical method. In addition, the method of fluid-structure interaction is applied to investigate the structural strength of the fully-loaded carrier under sagging and hogging conditions.

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1832 ◽  
Author(s):  
Michal Lipian ◽  
Pawel Czapski ◽  
Damian Obidowski

While the vast majority of the wind energy market is dominated by megawatt-size wind turbines, the increasing importance of distributed electricity generation gives way to small, personal-size installations. Due to their situation at relatively low heights and above-ground levels, they are forced to operate in a low energy-density environment, hence the important role of rotor optimization and flow studies. In addition, the small wind turbine operation close to human habitats emphasizes the need to ensure the maximum reliability of the system. The present article summarizes a case study of a small wind turbine (rated power 350 W @ 8.4 m/s) from the point of view of aerodynamic performance (efficiency, flow around blades). The structural strength analysis of the blades milled for the prototype was performed in the form of a one-way Fluid–Structure Interaction (FSI). Blade deformations and stresses were examined, showing that only minor deformations may be expected, with no significant influence on rotor aerodynamics. The study of an unorthodox material (PA66 MO polyamide) and application of FSI to examine both structural strength and blade deformation under different operating conditions are an approach rarely employed in small wind turbine design.


2014 ◽  
Vol 6 ◽  
pp. 815945 ◽  
Author(s):  
Hongjun Zhu ◽  
Hongnan Zhao ◽  
Qian Pan ◽  
Xue Li

A numerical simulation has been conducted to investigate flow erosion and pipe deformation of elbow in gas-solid two-phase flow. The motion of the continuous fluid phase is captured based on calculating three-dimensional Reynolds-averaged-Navier-Stokes (RANS) equations, while the kinematics and trajectory of the discrete particles are evaluated by discrete phase model (DPM), and a fluid-structure interaction (FSI) computational model is adopted to calculate the pipe deformation. The effects of inlet velocity, pipe diameter, and the ratio of curvature and diameter on flow feature, erosion rate, and deformation of elbow are analyzed based on a series of numerical simulations. The numerical results show that flow field, erosion rate, and deformation of elbow are all sensitive to the structural changes and inlet condition changes. Higher inlet rate, smaller curvature diameter ratio, or smaller pipe diameter leads to greater deformation, while slower inlet rate, larger curvature diameter ratio, and larger pipe diameter can weaken flow erosion.


Author(s):  
Se Yun Hwang ◽  
Jang Hyun Lee ◽  
Sung Chan Kim ◽  
In Sik Nho ◽  
Beom Seon Jang ◽  
...  

Sloshing assessment of LNG cargo tanks is expected to satisfy the required structural strength of insulation components. It is difficult to estimate the sloshing pressure and structural response of cargo containment in real size because of the uncertainty of intensive computation time as well as the complexity of sloshing motion. In this study, several procedural components are suggested to meet the endurable strength of LNG CCS during the design of LNG cargo containment. The measured sloshing impacts from small scale model test are treated by individual impacts. Thereafter, static and transient structural response of LNG CCS is sequentially performed in order to evaluate the structural strength. The structural response is also calculated in time series through convolution method considering the history of pressure. It is used to investigate the structural response induced by the history of impacts. Finally, an idealized fluid structure interaction on the localized insulation panel is investigated in order to evaluate the structural strength in actual scale.


2005 ◽  
Vol 2005 (1) ◽  
pp. 585-588 ◽  
Author(s):  
Azin Amini ◽  
Maziar Mahzari ◽  
Erik Bollaert ◽  
Anton Schleiss

ABSTRACT The most important aspect of the ongoing research project is to develop numerical coupled hydraulic-structural analysis models of oil containment booms. This should be later applicable for investigation of the efficiency limits of a new system of oil spill containment booms called Cavalli system. This system consists of surrounding the oil slick with a special boom and protecting it against waves and currents. It provides the possibility to divide the encircled area in several smaller circles and to increase the thickness of the oil slick inside. The whole system consists of a two-phase fluid (oil and water) and a boom that should be structurally stable for the pressure loads imposed by the fluids. It is finally important to evaluate the behaviour of the flexible skirt under different wave and current conditions, as almost all of existing research in the field have been undertaken for rigid barriers. To assess the behaviour of a flexible barrier fluid-structure interaction analysis is to be conducted. The problem is considered as a fluid-structure interaction problem as the boom usually undergoes large deformations and rotations, which modifies the flow characteristics during operation that is not the case for a rigid boom.


Author(s):  
M. Benaouicha ◽  
J. A. Astolfi

The paper presents a theoretical model of the fluid-structure interaction effect in two-phase inviscid flow. A time-space variation of the fluid density at the interface between a fluid and a rigid section is considered. The coupled problem is then written as a Laplace equation for the pressure with a boundary condition at the fluid-structure interface depending on the acceleration, the velocity of the structure and on the rate of change of flow density. It is shown that contrary to the homogeneous flow, the added mass operator is not symmetrical and depends on the flow through fluid density variation. The model shows also an added damping operator related to the rate of change of flow density. Added damping coefficients are found to be positive or negative, indicating the possibility of instability development into the dynamics of the structure.


Author(s):  
J.-H. Jeong ◽  
M. Kim ◽  
P. Hughes

Fluid-structure interaction (FSI) is the interaction of some movable or deformable structure with an internal or surrounding fluid flow. Therefore, fluid-structure interaction problems are too complex to solve analytically and so they have to be analysed by means of experiments or numerical simulation. This paper provides an overview of numerical methods for fluid-structure interaction evaluation in an draft IAEA technical guideline: large eddy simulation (LES), direct numerical simulation (DNS), Lattice-Boltzmann method (LBM), finite element method (FEM) and computational fluid dynamics (CFD) method. In addition to providing general applications of numerical methods for fluid-structure interaction evaluation, the paper also describes some cases applied for problems associated with single-phase flow and two-phase flow in nuclear power plants.


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