Performance improvement of archimedean spiral tidal current turbine based on parameter optimization

Abstract

To enhance the energy harvesting efficiency and operational stability of the turbine under low flow rate conditions, this paper introduced an Archimedean spiral horizontal axis turbine designed for low-speed currents. The influence of turbine on flow field and hydrodynamic characteristics under different tip speed ratios (TSR) were studied by changing the structure parameters and blade arc profile. A mathematical model was established based on mass conservation equation, and the relationship between the structure of the steam turbine torque was deduced. The results show the Archimedean spiral turbine displays higher capacitive coefficient at low TSR. With the increase of the pitch size, both the wake effect and the drag coefficient decrease smoothly, and the average power coefficient firstly increases and then decreases. When the D/L value equals 0.833, the capacitation efficiency reaches the highest value. The blade arc has a significant impact on the turbine efficiency, and different arcs adapt to different TSR conditions. Simulation results show the reasonable range of blade spacing is from 0.1D to 0.16D, otherwise the hydrodynamic performance of the turbine drops sharply. The findings of this study provide valuable insights for the design of turbines optimized for low-flow environments.