本文提出了一种无限深水中表面效应船(Surface Effect Ship,SES)尾波(Wash wave)数值方法.SES的尾波被表达成分布在气垫上的压力在静水中航行产生的兴波波浪场.在线性势流假设下,该尾波可解析地表示为积分形式,而其被积函数带有奇性并高频振荡.文中提出了一个变换,使变换后对不同的航速,SES船形(气垫形状)和所要计算的波浪场位置尾波计算中的被积函数是单调变化,因而易于数值计算.积分中的奇性也予以去除.数值计算结果表明本文提出的数值方法具有较高的计算效率而且结果与已发表的结果吻合良好.文中给出了一些SES船尾波(Wash wave)的计算结果,并进一步分析了SES尾波(Wash wave)中的局部和非局部波浪场成分.文中还尝试使用本文方法预报常规高速双体船的尾波(Wash wave),结果发现预报与水池测量结果相当吻合.
A numerical method is presented for predicting wash waves of Surface Effect Ships (SES)at deep waters.The wash waves of the SES are represented by the wave-making of a moving rectangular pressure distribution over the air cushion. Basing on the linear potential theory, the wash waves can be analytically expressed as integrals whose integrands oscillate with high frequency.The numerical procedure involves transformation of the integral variables,such that the integrands are monotonic for different vessel speed,shape of the pressure patch and locations of the wave to be calculated,and easy to facilitate the numerical calculation.The singularities of the integral can be also removed. Numerical results show that the present method is of high computational efficiency and with good agreement with the published results. Some results of wash waves of SES are presented and discussed.The characters of local and non-local effect parts of the wash wave of SES are discussed. Attempt is also tried to apply the present method in predicting wash wave of conversional catamaran,the comparison between the prediction and the model test measurement shows fairly good agreement.