偶极分布法计算近水面水翼的升力和兴波

DOUBLET DISTRIBUTION METHOD FOR CALCULATION LIFT AND WAVE PATTERN OF A HYDROFOIL

本文用水翼中拱面和尾涡面上偶极分布的方法计算在静水翼航状态下水翼的水动力性能。由于导出了计及兴波影响的四边形偶极单元的诱导速度计算公式,折曲状的尾涡位置可以比较精确地迭代确定,所以水翼升力和兴波的计算比以往的方法有较大改进,并可为多翼系统干扰的计算提供依据。

A numerical method is presented for calculating the hydrodynamic characteristics of a hydrofoil moving with constant forward velocity at fixed depth of immersion beneath the water surface. The principal feature of the method is to distribute doublet on the mean-camber surface of the foil and the trailing vortex sheet. With consideration of surface wave effects formulas for computing velocity at any field point induced by a moving quadrilateral panel of uniform doublet distribution are derived and have been utilized in the iterative procedure to determine the downstreamlocation and roll-up of the trailing vortex sheet. Thus the calculations of lift force and the surface pattern have been improved by comparing with the vortexlattice methods. The paper also provides the theoretical basis for predicting the interference of a multi-hydrofoil system.