Fatigue Life Assessment on the Star Frame of the Ampelmann System

Comparative Fatigue Analysis of a Tidal Turbines Support Structure

Reduced - complexity experiment for validating Fluid-Structure Interaction in ComFLOW

Human activities in marine environment are expanding to more remote locations, exposing offshore structures and commercial vessels to more adverse environmental conditions. On the other hand, market has a continuous demand for more cost efficient designs. Therefore, the need for more sophisticated computational tools arises. In these tools, the...

Low Frequency Second Order Roll of a Semi-Submersible Crane Vessel

Heerema Marine Contractors is constructing a new semi-submersible crane vessel, the Sleipnir. Due to low initial stability, semi-submersibles may present significant wave induced resonant motions in heave, roll and pitch. For practical reasons, especially the roll motion could play a limiting factor for future lift operations of the Sleipnir. In...

Dynamics of Vortex Cavitation

This thesis describes the mechanisms with which tip vortex cavitation is responsible for broadband pressure fluctuations on ship propellers. Hypotheses for these are described in detail by Bosschers (2009). Validation is provided by three main cavitation-tunnel experiments, one on a model propeller and two on a stationary wing. These have...

Application of extreme value theory for the assessment of turret moored floating structures

In the design of mooring systems, it is a common practice to use a 100-year design environment to calculate extreme responses. Statistical inference is executed on the environmental data to produce a 100-year environment. This 100-year environment is then simulated to calculate the loads that occur when the vessel is under the influence of the...

Proactive Control of Fast Ships: Improving the seakeeping behaviour in head waves

Fatigue resistance of welded joints in aluminium high-speed craft: A total stress concept

Crew transfers, surveillance duties and {security, rescue, interception} operations at sea typically require high-speed craft. Aluminium is quite often selected as hull structure material because of its weight save potential in comparison to steel. The fatigue strength, however, may become a point of concern because of the decreased Young’s...

Longitudinal ultimate bending strength analysis of ship structure for emergency response

The last three years have witnessed many maritime accidents (like “Costa Concordia”, “Mol Comfort”, “MV Smart”, etc), which led to serious consequences including the loss of human life and asset and environment pollution. In order to mitigate loss, maritime emergency response requires time-saving. So, a fast numerical tool is very important for...

Analysis of a Hybrid RaNS-BEM Method for Predicting Ship Power

Predicting the equilibrium between a ship’s required thrust and resistance is a complicated problem. Shipyards have to pay big penalties when a ship does not run at its design speed at a specified required power. An accurate prediction of the ship’s self-propulsion point is thus of huge importance. In the determination of the self-propulsion...

Ocean Waves Reanalysis of Operational Based Method: Wave Forecast Error based on the encountered OCTOPUS wave database

Dockwise started in 2008 with the OCTOPUS motion monitoring and captain decision support system for performance optimization and bad weather routing capacity. The OCTOPUS-Onboard system gathers weather and motion data, which is collected in the OCTOPUS database. This database includes the encountered weather data and the measured accelerations...

The effect of sloshing in partially filled spherical LNG tanks on ship motions

This report describes two methods to analyse the effect of sloshing on ship motions. The first method applies linear potential theory on both the barge and the internal tanks. For the barge the radiation, diffraction and incoming wave potentials are solved. For the internal tanks only the radiation potential is calculated, as there are obviously...

Improving the operability of planing monohulls using proactive control: From idea to proof of concept

The demand to sail at high forward speeds in both calm water and in a seaway remains high. For various patrol, search and rescue or military operations attaining high forward speeds is essential. In head and bow quartering seas, the main factor for voluntary speed reduction is the occurrence of large vertical peak accelerations. The occurrence...

The effect of platform motions on turbine performance: A study on the hydrodynamics of marine current turbines on the floating tidal energy converter BlueTEC

Application of the computational fluid dynamics solver FLUENT to keels of sailing yachts

The keel of a sailing yacht has been shown to constitute a significant part of the overall resistance. Where the details of this effect are not yet fully understood, Computational Fluid Dynamics (CFD) analysis might reveal mechanisms unseen to the experimental eye. An important step in CFD application is the simulation of a number of validation...

Aircushion Supported Mega-Floaters

The increase of the global population and expanding coastal mega-cities will necessitate an innovative pursuit of the utilization of the ocean space in which mega-floaters will play an important role in the future. These types of structures are very large floating artificial islands that can be used for various facilities and purposes similar to...