Numerical Simulation of Vortex-Induced Vibration in Inclined Elliptic Cylinders for Marine Energy Applications

Vortex-induced vibration (VIV), as a typical fluid-structure interaction phenomenon, is widely observed in marine engineering structures. Due to its resonant characteristics, it has the potential to generate substantial hydrodynamic energy and is considered as a novel approach for energy development. This study employs the force element method to perform numerical simulations of VIV for an elliptic cylinder inclined at an angle of θ = 45° with two degrees of freedom, under the Reynolds number Re = 200, mass ratio m* = 10, reduced velocity Ur = 1~14, and damping ratio ξ = 0. The results are compared with those of a circular cylinder under the same parameters. The findings indicate that, when locked in, the elliptic cylinder exhibits a significant amplification in transverse amplitude compared to the circular cylinder, with a delayed and wider locking range. Additionally, the contribution of the volume vorticity lift coefficient (Clv) is stronger for the elliptic cylinder than for the circular cylinder. The elliptic cylinder at a 45° inclination demonstrates a pronounced excitation effect compared to the circular cylinder. In engineering applications, stimulating the efficiency of marine current energy generation devices can be achieved by installing inclined elliptic cylinder fairings.