Hydrodynamic coefficients of a dropper line in North Sea conditions: On the drag and inertia coefficients of a Mytilus edulis dropper line submerged in water for a wide range of Keulegan-Carpenter numbers and high Reynolds numbers

Coastal communities around the world are facing significant challenges such as erosion, flooding, and storm surges. These issues highlight the need for nature-based coastal management solutions that can help mitigate the negative impacts of these events. Coastbusters Consortium developed such a solution in the North Sea. This solution is a...

Assessment of the Dynamic Stability of Tugs in Escort Using CFD

In this thesis, the influence of a combined drift angle, heeling angle and forward speed on the stability of a tug is researched. This is done to gain insight in the stability of tugs during escorting, where they operate at high drift angles, heeling angles and forward speed. The Damen RSD 2513 tug was simulated in steady CFD simulation using...

Motion prediction of a Semi-Submersible Crane Vessel at inconvenient draft: Identifying the cause of the discrepancies on an experimental basis

During specific operations, offshore marine contractor Heerema Marine Contractors reduces the draft of their Semi-Submersible Crane Vessel (SSCV) such that the floaters are submerged in close proximity to the free surface. This draft is also known as inconvenient draft. At this draft the motions of the vessel do not fully comply anymore with the...

Optimising the Geometry of a Breakwater Connected to Large Floating Structures: Increasing the Feasiblity of Floating Cities

The development of floating islands is an attractive option to provide living/working spaces at sea, as it would be a more economical solution for many locations at sea where the water depth is high. However, large second-order wave forces cause the floating island mooring system to become expensive as the wave height increases. So, in many...

Numerical investigation of bubble entrapment with tip vortex via an Eulerian-Lagrangian approach: Bubble motion near a tip vortex

Tip vortex cavitation around the marine propeller is the primary source of the underwater noises emitted by ships. Investigating the tip vortex inception is important to understand the aforementioned side effect. The water quality, highly related to the bubbles population, surrounding the tip vortex is crucial to the tip vortex cavitation...

Maneuverability of Wind-Assisted Ships: A Time Domain Simulation Tool

Wind-assisted ships are installed with wind propulsors capable of generating thrust for aiding the propulsion of the ship, with the purpose of saving fuel by reducing the required propeller speed and thus engine power. Wind-assisted ships are becoming more common due to high fuel prices and rising environmental concerns. The subject of this...

The Influence of Aeration and Deadrise Angle on Impact: An experimental and numerical study of the influence of deadrise angle and aeration on maximum impact pressure

When sailing in heavy seas, it happens that the water washes over the bow. This shipping of water is generally divided into two types. The term white water is used when the water is more of a spray and is generally harmless. Green water is more violent and can pose a danger to the crew and structures on board. <br/><br/>Research on green water...

Ship Motion Predictions in the Time Domain: using identified linear and non-linear force coefficients

Deterministic predictions of wave induced ship motion are increasingly often used to enlarge the oper- ational envelope of ships that perform complex operations at open sea. The large amount of complex operations performed nowadays, motivates the relevance of motion predictions. The company Next Ocean provides these forecasts, based on linear...

The assessment of aerodynamic interaction between Ventifoil suction wings: A comparison between a numerical lifting line approach and full-scale RANS simulations

While the awareness of global warming rises, transport over sea remains a large contributor to green house gas emissions. New regulations imposed by the International Maritime Organization (IMO) aim to reduce the emission of green house gasses. Consequently, ship owners turn to technological solutions in order to achieve this. The Ventifoil from...

Breaking wave impacts on the front deck of a ship: An experimental and numerical study about green water on ships in focused breaking waves

Green water events on ships in extreme waves pose a considerable risk to personal, operational, and structural safety. Considering these issues, novel experiments were done to investigate the interaction between focused breaking waves and a ship at forward speed. The investigated interactions are global motion, global loads, and forces on a deck...

Towards a standardized statistical correction between RANSe-based full-scale CFD and sea trial measurement

This research considers Amels LE and SX super yachts. Bare hull, appended hull, and actuator disk simulations were performed using CFD, and compared to sea trial results. The results of the CFD are unique because they were generated after the sea trials were conducted, resulting in the ship speed in CFD and sea trial being similar. The results...

On the effect of the heave motion on the run-up flow: The case study of a 2-D rectangular structure

Wave run-up is the vertical water uprush that occurs when an incident wave impacts on a surface-piercing body. This phenomenon is particularly relevant when waves of high steepness interact with large structures as a result of significant nonlinear interactions between incident and diffracted wave fields. The extent can be further amplificated...

Feasibility evaluation of a non-destructive estimation of material properties of FRC structures using ultrasonic guided waves

Variations in the production process of fiber-reinforced composite (FRC)materials often influence the material properties of the end product more substantially than their metallic counterparts. It can be valuable for the structural performance and reliability to have a better estimation of the properties of the FRC after production. Detecting...

Preventing Injuries of High Speed Marine Craft Operators: Incorporating Spinal Injury Models in the Analyses of Various Seat Suspension Principles

On board of High Speed marine Craft (HSC), the crew and the passengers are exposed to high levels of Whole Body Vibrations (WBV) and large magnitude Repeated mechanical Shocks (RS) caused by the motions of the craft. The HSCs are typically 10 meters long, capable of reaching a maximum speed up to 50 knots and widely used by various maritime...

Surrogate Based Optimisation for hull shapes with DAKOTA toolkit

The thesis proposes a methodology for a Surrogate Based Optimisation (SBO) study and its application in the Naval Architecture field using the open-source software DAKOTA. Surrogate Based Optimisation is a useful and powerful way of reducing time and costs in hull shape optimisation. It allows the employ of exploratory data analysis techniques...

On the determination of Hydrodynamic Coefficients for Real-Time Ship Manoeuvring Simulation

For the real-time simulation of ship manoeuvring, it is required to estimate the hydrodynamic forces with high accuracy. Current methods to determine the hydrodynamic coefficients prove to be time consuming and labour intensive. In this thesis, a method based on Singular Value Decomposition is proposed to determine the hydrodynamic coefficients...

Optimized position for a sponson on the Fairplayer with respect to the ship performance

Jumbo Maritime is a heavy lift shipping and offshore transportation &amp; installation contractor. The Fairplayer is one of the J-class vessels that is capable of performing offshore installation work. The two 900 ton Huisman cranes can lift up to 1800 ton combined, but the insufficient static stability of the Fairplayer results in a maximum...