Rotor Diameter (\( D_r = \sqrt{\frac{8 P_h}{\pi \rho_w \xi V^3}} \)):

Where:

• \( D_r \) is the rotor diameter, in meters (m).
• \( P_h \) is the hydraulic power, in watts (W).
• \( \rho_w \) is the density of water, 1000 kg/m³.
• \( \xi \) is the overall system efficiency, typically 0.1.
• \( V \) is the wind velocity, in meters per second (m/s).