Flow and Performance Characteristics of a Double-Blade Hydrofoil

While our planet is rapidly approaching an environmental crisis under the dominant use of depleting fossil fuels, the need for exploiting all forms of new, small carbon foot-print, renewable, and clean energy resources are increasing in the same proportion. Therefore, the need for exploring all types of clean energy resources that the world has- some of which might have not attracted sufficient attention before- is essential in order to implement sufficient, efficient, and widely use all them. In this respect, operational effectiveness of the wind and hydrokinetic turbines depend on the performance of the airfoils chosen. Using double-blade airfoils in the wind and hydrokinetic turbines, minimum wind and hydrokinetic flow velocities to produce meaningful and practical mechanical power reduces to 3- 4 m /s for wind turbines and 1-1.5 m/s or less for hydrokinetic turbines. Consequently, double-blade hydrofoils may re-define the potentials of wind power and hydrokinetic power of the countries in positive manner.