Aerodynamic Design Optimization of Residential Scale Wind Turbine Blades for Lower Wind Speeds

Abstract

Sustainable power generation using wind energy has been actively pursued around the world in the last few decades. Typical off the shelf commercially available wind turbines are optimized to produce rated output power at design wind speeds of 9 m/s to 15 m/s and performance significantly degrades at off- design lower wind speeds. Such high wind speeds are not available in South East Asia in general and Pakistan in particular. Hence, commercially available high wind speed turbine solutions have not been able to produce the manufacturer’s suggested power values at lower wind speeds of 6 m/s to 7 m/s. A need has been felt to aerodynamically optimize the wind turbine blades for lower wind speeds with an aim to increase the aerodynamic efficiency of power extraction as compared to commercially available high wind speed turbines. The blades for a domestic scale horizontal axis wind turbine have been aerodynamically optimized at wind speeds of 6 m/s to 7 m/s in order to produce maximum power output with a 5 ft blade length. The power output of aerodynamically optimized blades has been compared with the power produced by commercially available wind turbine blades having same span designed for 10 m/sec wind speed. The optimized blades not only produced at least 10% increased power but have also shown lesser structural bending under the same operating conditions. This paper aims at highlighting the methodology adapted for aerodynamic design optimization of domestic scale wind turbine blades at lower wind speeds of 6 m/s to 7 m/s along with the design and analysis tools/techniques used during this research. 

Keywords

• Wind Turbine Design, Blade Optimization, Blade Element Momentum Theory, Generalized Dynamic Wake Modeling, Wind Energy