Influence of Configuration of Hemispherical Artificial Reefs on Scouring Around Offshore Wind Power Pile Foundation

Abstract The burgeoning integration of offshore wind power and marine ranching underscores a pivotal avenue for the harmonized advancement of marine fisheries and sustainable energy. Central to this integration is the strategic deployment of artificial reefs (ARs), especially for mitigating scour around offshore wind power pile foundation (OWF). This study pioneers a three-dimensional numerical model, leveraging the prototype of China’s first offshore wind power-marine ranch demonstration project. Employing the Reynolds-averaged Navier-Stokes equations and sediment transport dynamics, the model intricately simulates fluid motion and sediment scour in the proximity of ARs and OWFs. The numerical results indicate that the proximity between a single hemispherical AR and OWF significantly dictates scour severity, with closer ARs (G/D < 2) exacerbating scour due to underdeveloped wake regions and increased turbulence. Conversely, at greater distances (G/D ratios of 2 and 3), ARs fully develop protective wake regions, effectively reducing scour depth by 37% and scour volume by 42% around the OWF. The study further reveals that specific arrangements of ARs can either mitigate or intensify scour effects. While parallel configurations of ARs demonstrate a notable reduction in scour depth and volume, this protective efficacy wanes with increasing P/L ratios, ceasing beyond a P/L ratio of 4. In contrast, a tandem arrangement of ARs, especially at a G/D ratio of 1, sharply intensifies scour volume around OWF. The findings are instrumental in guiding the design and arrangement of ARs in marine environments, aiming to enhance the structural stability of OWFs and contribute to the ecological harmony of marine systems.