A Numerical Investigation of Power Extraction using Biomimetic Hydrofoils for a Full Passive Oscillating Hydrokinetic Turbine

A new concept of hydrokinetic turbines based on oscillating hydrofoils using the biomimetic foils Dragonfly Canard and NREL-S814 comparing its power performance to that of a standard NACA 0015 foil is conducted in this study through the use of 2D simulations using URANS with Spalart-Allmaras as a turbulence model.The fluid conditions used in the study include =2 m/s, =997 kg/m^3, Re = 500,000, a chord length of 0.25 m, =90, and o=75 across all foils.The dimensionless frequency is f*=0.14, f*=0.20, and f*=0.12 were used across 3 cases.The heaving amplitudes used for Case 1&2 is Ho = c, while Case 3 is Ho=2c.The study gives insight into the advantages and disadvantages of using biomimetic foils.A symmetrical foil is observed to provide the best-performing foils in CP and results.Additionally, increasing the foil's frequency and heaving amplitude decreases flow detachment, improving the overall performance.