Numerical Study for the Variations of Flow Field During FKT Operation

Taiwan, surrounded by the ocean, benefits from the powerful Kuroshio Current along its eastern coastline, presenting substantial potential for harnessing marine energy resources. To capitalize on these opportunities, the National Academy of Marine Research initiated research and development efforts in 2020, focusing on key technologies for ocean current energy and conducting sea trials. These efforts are expected to culminate in the development of a Floating Kuroshio Turbine (FKT). To gain a comprehensive understanding of the FKT's underwater operations, this study employs a series of numerical simulations. Using the Navier-Stokes equations, combined with the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{k}-\varepsilon$</tex> turbulence model and dynamic mesh techniques, a numerical model for fluid-structure interaction is developed. The simulation results reveal that as flow velocity increases, the vortices behind the unit become increasingly complex. For the 20 kW FKT, the dual-blade system with counter-rotating blades reduces the downstream impact distance compared to a single-unit setup, limiting it to approximately 4 to 5 times the length of the unit's longest side. The primary objective of this study is to enhance understanding of the system's performance under different FKT, providing critical insights for future design optimizations and environmental impact assessments.