Effect of Blade Faults on the Performance Characteristics of a Vertical Axis Wind Turbine

Due to the diminishing reserves of fossil fuels and increased pollution from exploitation of these fuels, the world is focusing on the renewable energy sources. Wind is being considered as one of the prime next generation energy sources. Considerable amount of research is being carried out on the innovative designs for maximizing the performance of wind turbines. Furthermore, a lot of research is being carried out on maintenance and condition monitoring of such systems to improve the design of these systems [1, 2, 6]. To predict likelihood of a fault in such systems a variety of fault situations are being examined either numerically or experimentally. Most of the available studies deal with the presence of a single fault in the blades/structure of the wind turbines such as missing blade, deformed blades, blades with slits etc. In the present study two different faulty conditions of the turbine blades have been investigated, both individually and in combination, in order to estimate the contribution of each fault on the performance output of a vertical axis wind turbine. The torque output is one of the most important performance parameters of a wind turbine which has been shown to be quite sensitive to the faults in the blades of the wind turbines [3, 4, 5].The results depict that the presence of faults on rotor blade/s adversely affects the torque output of a Vertical Axis Wind Turbine (VAWT) and its effects can be seen in variations in the amplitude of the torque output. The study further shows that Computational Fluid Dynamics can be used as an effective tool to evaluate and analyze the presence of faults in a vertical axis wind turbine and can be used as an add-on to novel model based condition monitoring systems. Nomenclature r Radius of VAWT (m) ω Angular velocity (rads/sec) v Linear velocity (m/sec) P Power Output from VAWT (W) T Torque Output from VAWT (N-m)