Strategy of design of wind blade for low wind speed Algerian region

This research paper aims to design a linear wind blade shape that optimizes aerodynamic performance and increases annual energy production compared to the preliminary design. The proposed 500kw fixed-speed wind turbine has a design speed ratio of 6, a blade length of 27m, a rotation speed of 14 RPM, and a NACA 4412 profile. Which was designed to the value of 5.5m/s of mean wind speed registered in North Algeria. The method involves a linearized model derived from literature, where proposed blade models have root chords reduced to 75%, 70%, and 65% of the preliminary design value and the root twist angle reduced to 35% of the initial design. The blades are made of woven fabric with a 1970 kg/m3 density density. The spar thickness is 35% of the chord length in each section, while the shell thickness is 0.5%, 1%, 2%, and 3% of the chord length in each section. The results show that the best blade design is the 65% reduced root chord with 2% shell thickness and 35% spar thickness, which provides the same annual energy production as the preliminary design and presents a 3% mass reduction.