Energy harvesting from transverse galloping using a flexible crank-rod.

In this paper a coupled fluid-structure model of a flexible crank-rod connected to an electrical generator is analyzed and compared with other ways to extract energy from transverse galloping. One of the problems of energy harvesting is the conversion of linear oscillatory motion to a type of motion more compatible with an energy conversion device. One possibility is to transform the linear motion into a rotational one. The model considers a two degree-offreedom galloping oscillator where fluid forces are described resorting to a quasi-steady condition by using a quasi-steady aerodynamics model. Transverse galloping is a dynamic instability in which IDR/UPM (Instituto de Microgravedad Ignacio Da Riva, Universidad Politecnica de Madrid) has a large interest. This instability can be used for energy extraction. One possible application could be as a damping system for pressure waves in high speed railway tunnels. The wind speed induced by a pressure waves generated by a high speed train during its transit through a railway tunnel can surpass 5 m/s, and the train wake can induce speeds over 25 m/s. Due to the nature of the excitation and with a proper location for the device in the tunnel, these can be an optimal emplacement for devices based on aeroelastic instabilities such as transverse galloping.