Tidal current power is one of the promising renewable energy resources with high energy density, reliable energy supply and predictability of energy production. Recently many countries,
especially the U.K., announced and launched a number of tidal farm projects. For these projects to be successfully developed, each project should maximize its efficiency and productivity. The
optimization of the tidal turbine arrangement is one of the key issues to maximize the economic feasibility of tidal farms. This study introduces the diagonal arrangement of three tidal turbines
and investigates the performance of these tidal turbines in various arrangements using 3D CFD (Computational Fluid Dynamics) analysis. A tidal turbine of which maximum power coefficient is
47.5% was used to simulate the diagonal arrangement of three turbines. The results show that the diagonal arrangement increases the rear turbine efficiency by 3% and decreases the front
turbine efficiency by 0.5%.