Research on the hydrodynamic performance of a small ocean current turbine with deflectable blades

In recent times, there has been a significant focus on harnessing hydrokinetic energy in the vast depths of water, with the aim of effectively supplying electrical energy to unmanned underwater mooring platforms situated underwater. This paper delves into the feasibility of utilizing a vertical axis turbine as a sustainable and reliable source of electrical energy supply for unmanned underwater mooring platforms. Additionally, it presents a novel drag-type vertical axis turbine that incorporates blade adaptive tuning. This innovative design aims to enhance the hydrodynamic efficiency of the turbine by reducing the drag force experienced. In order to assess the hydrodynamic capabilities of the newly proposed turbine, numerical simulations were conducted at various tip speed ratios, while also comparing its performance to that of a fixed blade turbine. The findings indicate a noteworthy enhancement in the power coefficient of the innovative turbine, exhibiting a maximum improvement of 71.14%. Notably, the performance of the new turbine is contingent on the stiffness of the blade's torsion spring. As the torsion spring stiffness increases, the power coefficient of the turbine initially rises before reaching a peak and subsequently declining. Remarkably, the power coefficient of the turbine reaches its maximum of about 0.205 when the tip speed ratio is set to 0.6.