Impact of Blade and Solidity on the Performance of H-Darrieus Hydrokinetic Turbines by CFD Simulation

Abstract

Purpose: In the present work, the 2D design of H-Darrieus turbines with a diameter of 900 mm and NACA blades 0018, 0025, 2415, and 4415 has been carried out for the solidity values of 0,5; 1 and 1,5. In order to know its maximum performance. Method/design/approach: The 2D simulations were developed with the ANSYS® FLUENT package in the transient state, varying the angular velocity (ω) for a peak velocity ratio (TSR) of 1 to 7 and the SST K-ω turbulence model, for a constant water flow rate of 1 m/s. This in order to know the results of the torque (Nm) generated and thus calculate the power coefficient (Cp). Results and conclusion: The NACA 0018 blade reached a power coefficient of 0,604 for a solidity of 0,5, followed by NACA 2415 blade at the same solidity with a maximum Cp of 0,594. On the other hand, the NACA 0025 blade for solidity of 1 reached a maximum Cp value of 0,570, while the NACA 4415 profile with a solidity of 1,5 obtained a maximum value of 0.495. Research implications: These results of maximum Cp values were given in a TSR range of 2 to 4 with a mean value of 3,5 for NACA profiles 0018 and 2415. Thus, evidencing the behavior of this type of turbine reaching maximum values to then begin to decrease. Originality/value: The present work contributes to the understanding of the impact of geometrical parameters on the operating coefficient of H-Darrieus.