浅窄航道非线性兴波阻力数值计算

Numerical Calculation of Nonlinear Wave-making Resistance in Restricted Water

应用Rankine面元法计算船舶在浅窄航道中作匀速直航运动时的非线性兴波阻力.基于势流理论,在船体表面、自由面以及岸壁分布Rankine源来表达流场速度势,利用迭代方法满足非线性自由面边界条件,采用映像法满足水底边界条件,采用网格错位法满足辐射条件.以Wigley数学船型为例进行计算,通过改变航速和航道宽度参数,得到相应的兴波阻力.通过分析不同航速下航道宽度变化对兴波阻力的影响,得到了一些有意义的结论.

A Rankine Panel Method is developed for calculating the nonlinear wave-making resistance of a ship moving forward with a constant speed in restricted water. On the basis of potential theory, the disturbance velocity potential is expressed by a Rankine source distribution on the body surface, free surface and bank sides. The nonlinear free surface condition is satisfied in an iteration manner, whereas the boundary condition on the bottom is satisfied by the method of images, and the radiation condition is satisfied by the numerical technology of staggered grids. Numerical calculations are conducted for a mathematical Wigley ship and results are obtained for the ship at different speeds and widths of waterway. The effect of the width on the resistance is analyzed and some meaningful conclusions are drawn.