Harnessing Energy from Wind Induced Vibrating Structures

Abstract

This paper focuses on the harnessing of energy from fluid induced vibrations of bluff bodies due to the phenomenon of vortex shedding. Vortex shedding causes oscillating drag and lift forces due to which the bluff body in question experiences transient forces causing it to vibrate. An experiment has been conducted to investigate the potential of such vibrations and its probable usefulness. Maximum achievable efficiency of the system has been calculated and techniques to convert this mechanical energy into electrical energy have been discussed. In this experiment the bluff body used is a simple circular cylinder. The model developed works on the phenomenon of vortex shedding and resonance. The innovation of the setup is that the natural frequency of the structure can be easily altered by changing the relative distance between two of the mounting springs or by simply using springs of a different stiffness, as a result it can be ensured that the natural frequency of oscillation of the structure is always nearly matched to the frequency of vortex shedding for a wide range of wind velocities thereby ensuring a near resonance condition always.