Numerical Analysis of Hydrokinetic Energy Harvesting from Flow-induced Vibration of a Cylinder with a Single Protrusion

To better capture current energy based on flow-induced vibration (FIV), a new cylindrical oscillator is proposed in this paper that attaches a single protrusion to a bare cylinder with different shapes (square, triangular, and semi-elliptical) and different circumferential locations (a = ۰°, ۴۵°, ۹۰°, ۱۳۵°, ۱۸۰°). Two-dimensional (۲D) numerical simulations were performed to investigate the vibration characteristics, equilibrium position, wake vortex mode, and energy harvesting characteristics of the cylindrical oscillator over the reduced frequency range of ۲ ≤ U*≤ ۱۴. Regarding the protrusion angle, the vibration amplitude of the cylinder was obviously enhanced at a = ۴۵° and ۱۸۰° but was suppressed at a = ۱۳۵°. Specifically, the vibration amplitude of the cylinder with the square protrusion can reach up to ۳.۱D, an increase of ۲۰۴% compared to that of the bare cylinder. Additionally, as the flow velocity increased, the equilibrium position of the vibrating cylinder at a = ۹۰° had the largest downward offset, reaching a value of -۲.۴۲D. The maximum power of ۱.۳۳ W was reached for the cylinder with the square protrusion at a = ۴۵°, but at a= ۹۰°, a stable energy recovery bandwidth was achieved. In addition, high energy harvesting efficiency was mainly concentrated on the extremely low flow velocity range, with a maximal efficiency of ۹.۶۷%.

کلیدواژه ها:

Flow-induced vibration (FIV) ، Energy harvesting ، Cylindrical oscillator ، CFD ، Passive turbulence control (PTC)