Wave-induced vibration of a fully submerged horizontal cylinder close to a free surface: a theory and experiment

This paper presented theoretical and experimental models for the investigation of the amplitude of the vertical motion of a cylinder by a two-dimensional linear wave, passing through a circular horizontal cylinder close to the free surface in water. To consider the effect of the free surface, the Gap ratio = d/a was introduced by dividing the distance d between the centre of the cylinder and the water surface by the radius a of the cylinder. In this study, the smaller the Gap ratio, the greater the effect of the free surface, and it was theoretically calculated that it caused severe fluctuations in the hydrodynamic coefficients. In particular, by expanding previous studies for the calculation of hydrodynamic coefficients, the oscillating amplitude of the cylinder close to the free surface was proved by experiment.

Automated summary

Theoretical and experimental models were presented for investigating the vertical motion amplitude of a cylinder near the free surface in water by a two-dimensional linear wave. The introduction of the Gap ratio allowed for consideration of the free surface effect, with smaller ratios resulting in greater impact. Experimental results confirmed the theoretical predictions, showing severe fluctuations in hydrodynamic coefficients at smaller Gap ratios.