CFD analysis of horizontal axis wind turbine braking system using chordwise spacing

Abstract

Wind energy is an environment- friendly and efficient source of renewable energy to meet the growing demand for energy. The wind turbines are designed to operate at rated wind speed. The sudden wind acceleration and wind gusts can overload the tower head causing immediate damage to the mechanical drive train shaft, gearbox, and turbine blade. The various aerodynamic braking systems are presently used to control the rotational speed of the wind turbine at extreme wind velocity. In this proposed approach, it is attempted to control the over speeding of the wind turbine aerodynamically by providing the chord wise spacing (slot) on the blade. The spacing provided on the blade alters the pressure distribution between the pressure side and the suction side of the turbine blade that brings down the rotational speed of the wind turbine within the allowable limit. In this approach, the over speeding of the wind turbine blades is effectively controlled without affecting the power generation. The primary parameter of the spacing i.e. chord wise position of the spacing is computationally analyzed.