Using the wind as an additional propelling force for modern cargo ships is on the rise. This is due to the regulations about greenhouse gas emissions. Various wind units are available to create a propelling force for the ship. One of these wind units is the suction wing. A couple of ships are equipped with it, like the Amadeus Saffier. Some reasons for choosing a suction wing are the compactness, controllability from the bridge and the ability to create higher lift than traditional sails.
The suction wing in itself has already been researched. Next to that, the optimal position in terms of counteracting its forces with the ship’s hydrodynamic forces is investigated. In the middle of these two lies the gap of the actual forces and interactions between the ship and the suction wing at sea.
This research investigates the interaction effects between the ship, deckhouse and wind units and how they influence the forces. The goal is to get insight into the interaction effects and their consequences.
Based on that, the suction wings can be positioned on the ship with minimal interaction and on fewer disturbed regions. Moreover, knowing the suction wing forces, which are expected to be generated at sea, leads to better estimations of the engine power reduction and savings in emissions. Additionally, this knowledge can be applied to design the ship and suction wings more effectively for use at sea on a wind-assisted vessel. All of this helps to optimise the wind-assisted ships and reduce emissions.
Computational fluid dynamics (CFD) simulations with the RBVMS (residual-based variational multiscale) code were conducted to get insight into the flow. A simple, real-size model of a ship hull, deckhouse and suction wing was created for the CFD simulation. The ship and suction wing were simulated separately, but also in a combined case. Results were obtained for two wind conditions, respectively a uniform wind of 10 m/s and a logarithmic wind profile in an apparent wind angle of 30∘. Reliable results were achieved based on a mesh size study for the individual cases. Additional studies were done for the suction wing to get reliable results. These included a domain size study and the calculation in 2D and 3D. Moreover, a realistic suction pressure and blowing velocity were identified and matched for each wind condition. The lift and drag coefficients were validated with experiments.
The 2D and 3D simulations of the suction wing showed that the 3D case is not an extrapolation of the 2D case. In the 3D simulation, the lift-induced drag plays a strong role, which is produced by the tip vortices.
The interaction effects were investigated with vector plots, the lift and drag coefficient and frequency spectra. The frequency spectra were realised through a polynomial fit of the forces and the Discrete Fourier Transform. The results showed a strong interaction between the ship and the suction wing. Especially close to the ship deck, more turbulence and a change in wind speed can be seen. For the simulated cases, the deckhouse stayed unaffected.
Superposition was investigated to determine if it is possible to have a faster way of knowing the wind above the ship deck at different angles and ship configurations at sea. Linear superposition was applied to the single simulations to compare them with the full simulation. Linear superposition can not represent the full simulation. Nevertheless, it can be used to get a better approximation of the flow behaviour of the full simulation than using only one single simulation.

Technological advancements are increasing system complexities, posing challenges for modern warship design. Early-Stage Ship Design (ESSD) is a vital stage, involving critical decision-making with limited information. The early-stage design of warships entails intricate decision-making considering temporal influences, interdependencies, external factors, trade-offs, high costs, evolving requirements, and other challenges. Developing well-defined system architectures is essential for managing these complexities. Model-Based Systems Engineering (MBSE) is pivotal for overcoming precision issues, inconsistencies, and difficulties in maintaining and reusing information associated with conventional document-centric approaches in systems engineering (SE).
Despite the growing popularity of MBSE, the maritime industry continues to rely on traditional document-centric approaches, lagging behind other sectors in adopting MBSE. These challenges stem from a lack of empirical evidence demonstrating MBSE's full benefits and confusion regarding its implementation practices. Moreover, there is a lack of comparative studies that assess how well MBSE tools are tailored for naval warship design. Thus, this research explores the value of MBSE in the early design stage of naval vessels. Specifically, the research aims to validate and demonstrate MBSE's benefits in developing systems architecture for warships, focusing on operational, functional, logical, and physical perspectives within the context of ESSD. By analyzing industry approaches and utilizing two representative modeling tools, this thesis provides practical insights, clarifies MBSE practices, and promotes its effective implementation in future naval design projects.
A structured research process is formulated to achieve the thesis objective. It begins by defining the mission, capabilities, and requirements. For illustration purposes, a hypothetical Landing Platform Dock vessel mission is chosen, necessitating the creation of fictitious capabilities and requirements. MBSE tools Capella and CDP4-COMET are then selected for this analysis. Next, a metamodel is established for a unified understanding among stakeholders, guiding decision-making throughout the design process. Once the baseline models are constructed, the validation and verification capabilities of the tools are evaluated. The baseline models are modified to simulate the dynamic nature of warship design. Finally, the tools are systematically assessed based on selected key MBSE factors: consistency, traceability, flexibility, and trade-offs.
Transitioning to conclusions, the analysis reveals that both tools effectively validate anticipated benefits. By synthesizing the knowledge gained, it is concluded that MBSE can enhance and accelerate the design process during the early design phase of warships. Capella demonstrates superior performance in the early design stages, whereas CDP4-COMET excels in the latter design stages. This emphasizes the critical role of integrating MBSE tools to enhance design outcomes, leveraging their strengths across diverse phases effectively. Thus, integrating MBSE tools and establishing a unified source of truth is one crucial aspect of advancing MBSE in ship design. Further recommendations are detailed in the thesis.

Climate change due to greenhouse gas emissions is prompting the IMO to reduce emissions by 80% by 2050. This thesis focuses on designing modular propulsion systems for mid-speed sailing vessels to meet these regulations. It designs a framework to generate and swiftly evaluate propulsion system designs on the basis of five performance indicators: Weight, Volume, Life Cycle Costing, Modularity and Emissions. Additionally, the framework is proven on the basis of a case study, which results in a modular concept.

The traditional approach of extrapolating the experimentally measured model resistance of a ship to full scale is based on the Froude assumption or the form factor assumption, where the viscous part and wave-making part of the resistance are dealt with in deep water. In shallow water, however, the water-depth dependency of flat-plate/ship frictional resistance as well as form- and wave effects are expected. It is found in this research that all of these three properties are deviating more or less clearly from the traditional understanding from certain water depths. In this dissertation, a correct understanding of the resistance of ships in shallow water from the very basis is provided to build a new approach to improve resistance prediction considering the water-depth dependency of the three features mentioned above. A method is proposed to improve the extrapolation of ship resistance for model-scale tests carried out in shallow water. The effects of limited water depths on the three components of ship resistance (i.e., frictional resistance, viscous pressure resistance, and wave-making resistance) have been studied individually. Empirical formulas have been developed for three ship types in various water depths. This approach can benefit all further qualities of the ship, e.g., a reliable performance prediction, truly valid rules for ship design and even future work on understanding ship propulsion in (extremely) shallow water when navigating in inland waterways and coastal waters. It also allows the further application of the well-accepted extrapolation method with at the same time taking into account the inherent deviations in shallow water.