Journal of Mechanical Engineering and Sciences (Mar 2017)
Fluid-structure interaction analysis of rear spoiler vibration for energy harvesting potential
Abstract
Increasing environmental and energy concerns constitutes an encouraging development of future automobiles and autonomous vehicles that utilize cleaner and renewable energy. Although primarily an aerodynamic device, car rear spoilers experience various vibrations and limited attention has been given to exploiting these vibrations for generating alternative energy. This paper aims to investigate the potential of using the flow-induced vibration of rear spoilers on automobiles for energy harvesting. To that end, a fluid-structure interaction analysis of an inverted NACA 2408 spoiler behind an Ahmed body was undertaken. An Arbitrary Lagrangian-Eulerian flow solver was coupled to a non-linear structural dynamic solver using a commercial software application. The vibrations of the rear spoiler placed at 0, 50 and 100 mm below the top face of the Ahmed body under Reynolds number Re = 2.7 × 106 were simulated. It was found that the vibration of the rear spoiler at the highest elevation showed the largest amplitudes and strain, but the vibration of the rear spoiler at the lowest elevation offers an extended period of vibration before reaching a steady state. With the rear spoiler positioned at the highest elevation, a vibration frequency of 70 Hz and a steady-state principal strain of 350 may be achieved. These vibration levels compared well with previous investigation to sufficiently charge storage capacitors for wireless transmitters. The rear spoiler vibration may offer potential means for energy harvesting, and warrants further experiments under actual driving conditions.
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