Effects of the Hydrofoil Geometry on the Small Horizontal Hydrokinetic Turbines' Performance.

This article presents the findings from a numerical study on hydrokinetic turbines for application in isolated and low populated areas. A numerical code for the determination of the performance of horizontal axis hydrokinetic turbine is developed based on the blade element momentum method, optimized and validated. It is intended to investigate hydrofoils which are easy to manufacture and to maintain. These hydrofoils include hydrofoil and the Joukowski J 0015, GO 410, flat plate and NACA 0024 (reference) hydrofoils. The effects of the chord and twist angle distributions are investigated, and their influence on the hydrodynamic performance is evaluated. The results showed that the linear twist angle distribution along the blade showed the best performance. The power coefficient for the Joukowski J 0015-, Gottingen GO 410- and NACA 0024-based rotor blades is, respectively, 0.512, 0.506 and 0.513 indicating the good performance of the Joukowski hydrofoil. The combination of the Joukowski J0015 hydrofoil with linear chord and twist distributions showed the best performance. The flat plate hydrofoil-based rotor with constant chord and linear twist angle distributions showed a reasonable power coefficient of 0.324 and can be a viable solution considering facility of manufacturing and maintenance. [ABSTRACT FROM AUTHOR]