Suspension ships belong to a novel ship type that employs a suspension system as part of the ship’s body. Suspensions used in land vehicles are well-known for their abilities of enhancing land holding performance and isolating shocks to improve ride comfort. The adoption of suspension systems in ships aims to achieve similar functions. However, it is important to note that the ocean wave...
Conventional space-time domain simulations suffer from the explicit breaking of continuum symmetries, once a mesh is introduced. In turn, central quantities, such as e.g. energy or angular momentum do not remain preserved after discretization. In this talk we present a novel geometric variational discretization for second order initial value problems (IVPs) [1], which builds upon insight from...
Offshore support structures are critical for offshore bottom-fixed wind turbines. The support structures are generally subjected to a harsh environment and require a design life of more than 20 years. However, the design validation of the support structure normally needs thousands of simulations, especially considering the fatigue limit state. Each simulation is quite time-consuming. This work...
Submarine pipelines can be divided into three types based on their laying status: pipelines laid flat on the seabed, pipelines without buried, and pipelines buried in shallow trenches. In addition, there is also a suspended span state caused by waves and currents erosion. The four laying states of submarine pipelines indicate that the seabed, as the foundation supporting the pipeline, must...
The dynamic responses of a floating dock under corrosion-induced accidents are studied using a numerical method. The numerical model is developed to simulate the dynamic process of the floating dock’s operations, which includes a six-degree-of-freedom (6-DOF) model, a hydrostatic force model, a hydrodynamic force model, and a hydraulic model. The hydrostatic force model is developed using the...
Submersible fish cages are designed for installing in the open sea sites that are subjected to violent sea conditions to reduce the hydrodynamic forces acting on the fish cages. To assess the dynamic responses of a single point mooring submersible fish cage under the rough sea conditions, a numerical model including hydrodynamic and structural methods is proposed. The waves and currents are...
Wave-induced motions and loads on a moored and articulated multibody offshore structure are investigated through numerical analysis. A coupled mooring-joint-viscous flow solver is employed to account for mooring dynamics, joint restrictions, nonlinear rigid body motions, and viscous flow effects. The study focuses on two modular floating structures (MFSs) connected by a flexible joint, with...
This study investigates optimizing the front wall geometry of an Oscillating Water Column (OWC) chamber to enhance turbine performance and output efficiency when harnessing progressive waves with consistent periods and wavelengths. Numerical Wave Tank (NWT) adopted simulations carried out using ANSYS-Fluent package, VOF method with multiphase flow (air-water) where 2-D wave motion of NWT...
The offshore wind energy industry has witnessed rapid growth in the past decade. Still, there is a lack of commercial floating wind projects due to the relatively high development costs and other factors. To facilitate the holistic evaluation of floating wind farms in Norway, this article investigates the levelized cost of energy of a floating offshore wind farm and its economic feasibility....
Transport dynamics and mapping of marine litter pathways are of relevant attention today due to its imposed environmental, social, and economic threat. As such, an abundance of models inspecting ocean dynamics and particle tracking systems have populated the literature. This study couples with these existing models by defining a generalized framework called “MATT’S PATROLL: MArine liTTer’S...
In this study, we are addressing the energy issues related to offshore technologies. Due to stringent emission and fuel efficiency standards, there has been a great deal of interest in energy conversion technologies. Among various energy conversion systems, thermoelectric generator (TEG) has garnered much attention because of its advantages, such as solid-state energy conversion, small and...
Abstract:
The present paper investigates the hydrodynamic performance of the Vortex-Induced Motion Energy Converter (VIMEC) oscillator modeled in OpenFOAM computational fluid dynamics (CFD) framework. The model employs an overset (chimera) grid approach to allow time-domain simulations with large body displacements and complex motion patterns.
A series of sensitivity and validation...
In normal de-ballasting operations of floating docks, each ballast pump manages a specific group of ballast tanks, independently of the others. However, if one pump is malfunctioning, a connection valve between the group and its adjacent group is opened, allowing its adjacent pump to control two groups of tanks simultaneously. This study aims to investigate the de-ballasting dynamic process in...
The dynamic behaviours of the lifting operation of a gravity-type fish cage under calm sea conditions are investigated in this study using an extended position-based dynamics (XPBD) method to obtain the structural deformations of the aquaculture nets. The original XPBD is improved to accurately predict the tensions of the aquaculture nets by applying correction forces. The present XPBD is...
On-bottom stability design for shallow water cables and pipeline sections has primarily been performed adopting analytical methods or 1D and 2D computer tools that does not correctly account for effects such as tension developments, free spans, open trenches, seabed features or curved sections along the route. These effects have been studied and addressed in the recent DROPS JIP Phases I and...
The concept of a suspended inter-array power cable assumes that the cable floats submerged within the water column instead of being laid on the seabed. This setup requires additional equipment, such as buoyancy modules or buoys, to achieve the desired cable configuration. The implementation of buoyancy modules introduces abrupt changes in stiffness between the cable sections with clamped-on...
Gas-Liquid cylindrical cyclone separator (GLCC) is a compact separator that has been widely used in petroleum production. The inlet configuration has significant influence on the separating capacity of the GLCC separator. By using both FEM simulation and practical experiments, three inlet configurations and twelve inclined angles are investigated to find the optimal inlet configuration for...
Recently, due to the nearshore oil fields in Vietnam were nearly exhausted, oil and gas extraction proceeds to deeper water areas using the mooring floating offshore structures. Therefore, the durability of the mooring system in deep water should be studied through determining the dynamic tension of the mooring line system using random wave models. However, full stochastic dynamics analysis...
Dynamic responses of a combined wind and wave energy system which consist of a 5MW semi-submersible floating offshore wind turbine (FOWT) and a torus-shaped wave energy converter (WEC) are investigated. In the investigated configuration, the torus WEC is constrained to only move in the heave direction with respect to the FOWT. This results in a two-body dynamic system that allows for the...
