In 2022 the first 12 MW offshore wind turbines are expected to be installed. Due to the continuous upscaling of wind turbine generators new problems are expected to arise during the installation of the turbines. Especially the workability of the installation of larger wind turbine blades, which are already causing problems during the installation of 8.4 MW turbine blades, are questioned by Van Oord. This research focuses on the alignment process of the blade with the hub, which is considered to be the limiting factor in installing wind turbine blades. The ultimate goal is to reduce single blade installation times by facilitating the alignment process To investigate how different environmental conditions influence the dynamic behavior of the blade in the alignment process, a numerical model is developed. The motions of the blade, forces in the taglines and aerodynamic forces on the blade are evaluated for different environmental conditions during 30-minute simulations in the time domain. Wind velocity, turbulence intensity and the angle of the incoming wind relative to the blade are environmental parameters that influence the motion of the blade. Results for a 8.4 MW reference turbine blade are compared to a 12 MW turbine blade and conclusions are made concerning the installation workability for larger turbine blades. Results show that the displacement of the blade root is caused by the rotation of the blade and installation tool around its x- and z-axis. The response spectrum of the blade root motions contains a significant amount of energy at the lower frequency part of the spectrum. In this part the first and second natural frequency of the system occur, which correspond to the rotations that are the main causes of the blade root displacement. The effect of wind speed, turbulence and incoming wind angle on the response of the blade is significant. Furthermore simulations are conducted for different rotation angles of the blade in the blade installation tool, which can result in large reduction, around 50%, of blade root motions. The responses of larger turbine blades (length 107 metre) increase compared to a smaller turbine blade (length 80 metre). Workability is expected to decrease due to the increase in blade root motions. Based on the results of the analysis, several improvements are proposed for decreasing the blade root motions using the existing tagline set up. Using a different angle of the blade in the installation tool and increasing the tagline tension both decrease blade root motions. A solution using an extra tagline is proposed and discussed to show how the current setup could be improved.

New vessels need to remain fuel flexible in order to handle the uncertainties of the future regarding the available alternative fuels aiming to lower their environmental impact. On the other hand, it is even more challenging for existing vessels that are not fuel flexible to successfully improve their carbon impact. The current study examines the combustion characteristics of alternative maritime fuels including methanol and hydrogen in the compression-ignited internal combustion engines of Bravenes that burn diesel fuel, as well as the implications these fuels have on the environment and on safety when used onboard ships. The diesel fuel still acts as the main fuel but also as the ignition fuel for the injected additives. The purpose of the additives is for the substitution of diesel and to offer more complete combustion in the cylinders. Van Oord is already implementing the Fuelsave Marine+ technology on board Bravenes. This technology aims to reduce harmful emissions like ABe and greenhouse gases while also increasing engine efficiency in order to contribute to the overall energy transition effectively. Therefore, the primary goal of this research is to examine if there are any potential impacts of the technology on the efficiency, emissions, and fuel consumption of Bravenes engines.

The model used is able to characterize the combustion of the engine using the Seiliger combustion shape parameters a, b and c. These parameters consider the combustion efficiency, the ignition delay, and the heat fractions of the potential heat for the appropriate stages. The effects of the additives in small quantities can be seen in the combustion duration and the ignition delay of the combustion. In order to properly model the additional fuels effects some of the diesel mass needed to be substituted with methanol mass to provide the same energy content in the cylinder. Attention was also given to the proper selection of the KN&𝑋𝑏 parameters impacting the combustion shape parameters, and as a result the pressures and temperatures in the engine.

The results of the model for the diesel and diesel with additives operation predict a decrease in diesel fuel consumption which is a good indication of 𝐶𝑂2 emissions reduction. The peak cylinder pressures have increased with the additives injection and the peak temperatures as well which indicate an increase of 𝑁𝑂𝑥 emissions. The increase in the temperatures is not something expected in reality and could be due to a modeling effect. The indicated work of the engine combustion cycle also improved for the Fuelsave technology but due to the increase in peak pressures the mechanical efficiency decreased resulting in reduced effective efficiency. The selection of the Seiliger settings, which allowed
for a higher heat loss efficiency than was realistically anticipated, is another factor contributing to the decrease in effective efficiency. All in all, proper measurement campaign needs to be performed to show the clear effects of the technology as a retrofit solution on board existing vessels for efficiency and emission reduction.