Energy Harvesting Potentials of Flow-Induced Vibrations for Trapezoid and Square Bodies: Numerical Simulations and Analyses

摘要

Energy harvesting through various flow-induced vibrations has been extensively studied for the last two decades. The focus of this work is to numerically simulate transverse galloping and vortex-induced vibration phenomena of square and trapezoid cylinders for energy harvesting at various angles of incidence. The structure is modeled as elastically mounted supported by linear spring and damper. Incompressible Navier-Stokes equations are the governing equations for the flow. The mass ratio is set as 15.1 while the damping ratio is 0.00295 giving mass-damping ratio of 0.0000695. Numerical simulations are performed at Reynolds number (Re) of 2500 based on the in-flow velocity and the width of the cylinder. The motion of the structure under the influence of forces is implemented through a user-defined function (UDF) dynamically hooked to the flow solver. Wind-induced transverse vibration of the bodies (galloping and vortex-induced vibration) is then simulated at different reduced velocities. The simulated data is also compared with those of previous experimental work. The results demonstrate that a trapezoid body has an extended range of galloping instability as compared to a square cylinder thus providing better energy harvesting potential.