计算斜航船流场和水动力的细长体理论数值方法

An Improved Numerical Procedure for Drifting Ship on the Slender Body Theory

本文考查了细长体理论数值方法中的数学问题，指出了用在其他论文中的一个有疑问的公式．椭圆的理论解被用来修正船首部因细长假设无效而导致的力的偏差，其中椭圆几何参数根据首部形状和体积求偶．为考虑尾部泄出的涡片，讨论了离散涡模拟和虚拟物体模拟，离散涡模拟看来在尾流可视化方面更合理．几条船计算的力分布及尾流场和试验结果吻合良好。

This paper reviews the mathematical problems in the numerical method of the slender body theory and points out a questionable formula used in the other papers.The theoretical solution of ellipsoid is applied in the revision of the force near the ship bow for the invalidation of slenderness assumption.The geometric parameters of ellipsoid are evaluated according to the bow’s shape and volume.To consider the vortex sheet emersed from the stern contour,the discrete vortices simulation and the imagined body simulation has been discussed and the discrete vortices simulation seems to be more meaningful in the visualization of astern flow.The calculated force distributions and the astern flow fields of several ships agree with the experimental results well.The calculated flow fields successfully reflect the effect of ship’s stern shape on the wake.