A Hybrid Metaheuristic-Based Approach for the Aerodynamic Optimization of Small Hybrid Wind Turbine Rotors

Table 1

Nomenclature of the BEM model.

Local axial induction factor		Free-stream wind speed [m/s].; Wind speed before crossing the blade segment.
Local tangential induction factor		Tangential flow speed after crossing the blade segment [30].
		Air density [kg/m^3].; Kinematic viscosity [m^2/s].
Azimuthally averaged axial induction factor; Azimuthally averaged tangential induction factor		Lift coefficient.; Drag coefficient.; Airfoil chord length [m].; Angle-of-attack [°].; Twist angle [°].; Inflow angle [°].; Rotor angular speed [rad/s].
Radial and azimuthally averaged axial induction factor		Chord radial solidity.; Number of blades.; Normalized radial position.
Reference tangential flow speed at a local segment [30]		Normalized radius of the blade root.; Radial distance [m].
Average axial flow speed crossing the rotor		Blade radius [m].; Rotor swept area [m^2].; Tip speed ratio.
Average axial flow speed in the far wake, where the; pressure has reestablished to the atmospheric value		Tangential force coefficient.; Normal force coefficient.