Numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder

This paper presents a 2-D numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder. A mathematical model of numerical wave tank with two-way fluid-solid interactions were developed and validated. The wave-induced vibrations of a single-degree-of-freedom cylinder were simulated at eleven gap ratios (d / a = 8, 10, 12, 14, 16, 18, 20, 22, 24, 28 and 32). Numerical results indicate that significant nonlinear characteristics are introduced into the originally linear waves with the presence of cylinder. Based on the variation characteristics of cylinder vibration amplitude, the gap ratios can be divided into three ranges, i.e., the uncertain range (8 ≤ d / a ≤ 14), quasi-linear range (14 ≤ d / a ≤ 20) and linear range (20 ≤ d / a ≤ 32). Under the same wave condition, the gap ratio does not affect the frequencies of vortex shedding and cylinder vibration. The presence of the cylinder complicates the flow field and suppress the vortex shedding around the cylinder.