正交直墙前直立圆柱振荡问题的研究

Study on the Oscillation of a Uniform Cylinder in Front of Two Vertical Walls Intersecting Normally

应用镜像原理 ,将正交直墙前单个圆柱在静水中的振荡问题 ,转化为 4个对称布置圆柱在静水中的振荡问题 ,由此应用速度势的特征函数展开法 ,建立了正交直墙前直立圆柱振荡问题的解析解。通过数值计算研究了圆柱与正交直墙间距离大小、水深等因素对附加质量和辐射阻尼的影响。计算结果表明 ,正交直墙前圆柱上的附加质量和辐射阻尼将明显增大 ,且随着波数的变化而发生振荡 ;

Based on the image theory, the oscillation of a cylinder in front of two vertical walls intersecting normally in the otherwise static water is transformed into the oscillating problem of four symmetrically arranged cylinders. The transformed problem is solved by an analytical method based on eigenfunction expansion. Numerical experiment has been performed in order to examine the influence of the distances between the cylinder and the walls and water depth on the added mass and radiation damping of the cylinder. The calculation shows that the added mass and radiation damping of the cylinder in front of the two vertical walls increase abruptly. The added mass and radiation damping oscillate with wave number, and the oscillating frequency increases with the increase of the distances between the cylinder and the walls. Furthermore, the added masses and radiation damping are linear with the water depth in the range of low frequencies.