This paper studies the sensitivity of drivetrain condition monitoring system (CMS) signals to blade damage, exploring how these signals, particularly vibration, can serve as a potential tool for detection and tracking damage progression. This is achieved using a decoupled simulation approach, combining an aeroelastic solver with a drivetrain model. First, aeroelastic simulations are performed in OpenFAST, where the low-speed shaft (LSS) forces, moments, and tower top position vector are extracted and transferred to the drivetrain model. The drivetrain is modelled using the multi-body simulation environment SIMPACK. Blade damage is introduced in OpenFAST by reducing stiffness in the flap-wise or edgewise direction. The reference DTU-10MW onshore wind turbine is used as a test case. First, the impact of blade damage on LSS shear forces is analysed. Then the drivetrain response is assessed using virtual velocity sensors placed at the main bearing, rear bearing and gearbox housing. Results indicate that damage occurring in the blade mid-span region shows higher sensitivity compared to tip and root locations. A positive correlation is observed between LSS shear force and bearings side-side velocity, with higher forces leading to increased vibration. Additionally, the trend suggests that higher stiffness reduction results in higher velocity, indicating damage progression.

In recent times, the point absorber Wave Energy Converter (WEC) has gained popularity due to its practicality. Investigating the parameters of the Hydraulic Power Take-Off (HPTO) in the WEC, including hose diameter and check valve variations, is crucial. This study analyzes optimization using the Sequential Quadratic Programming (SQP) method in MATLAB/SimScape, leading to a more comprehensive understanding of the interactions among HPTO components, such as hydraulic cylinders, check valves, hoses, accumulators, motors, and generators. Key system performance indicators, including pressure drop, flow rate, and power output, were assessed in both single and two-point absorber HPTO configurations. The optimization process yielded a maximum hydraulic power output of 7.33 kW, a mechanical power output of 6.41 kW, and an electrical power output of 5.4 kW using a 2-inch hose diameter. Additionally, utilizing a two-point absorber model enhanced power generation capacity by 47.4%, reaching 9.45 kW. The findings highlight the significant pressure drop at the check valve, with the 2-inch hose model experiencing a drop of 31.874 bar. These results demonstrate that optimizing HPTO parameters can significantly improve the efficiency of converting wave energy into electricity, providing valuable design recommendations for WEC technology.

In this paper, the hydroelasticity of two segmented ship models (Barge and KVLCC2) is investigated by experimental and numerical methods. A two-way Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) coupled method is adopted and further validated its accuracy against experimental results. The current approach emphasizes the overall convergence between two solvers, maintaining a strongly coupled manner to comprehensively address the fluid-structure interaction phenomenon, including the added mass effect. A series of experiments of a segmented Barge and KVLCC2 under various wave conditions were firstly conducted. The motions of the models are measured and the displacement Response Amplitude Operators (RAOs) are calculated. The CFD-FEA coupled method is demonstrated in agreement with experimental results by comparing the numerical prediction with the tank test results in terms of motion, affirming the validity and robustness. Finally, the hydroelastic response is discussed and investigated.