ABSTRACT

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.

摘要

本文提出了通过二维线性波研究圆柱体垂直运动幅度的理论和实验模型，该二维线性波穿过靠近水中自由表面的圆形水平圆柱体。为了考虑自由表面的影响，通过将圆柱中心与水面之间的距离 d 除以圆柱半径 a 来引入间隙比 = d/a。在本研究中，间隙比越小，自由表面的影响越大，从理论上计算，它会引起水动力系数的剧烈波动。特别是通过扩展前人对水动力系数计算的研究，通过实验证明了靠近自由面的圆柱体的振荡幅度。