基于Rankine源和Kelvin源格林函数求解兴波阻力的复合算法

Wave resistance calculation method combining Green functions based on Rankine and Kelvin source

[目的]运用边界元法计算船舶兴波阻力基本上是先求解船体附近的速度分布,然后采用伯努利方程进行压力积分,其计算过程复杂,且误差非常大。[方法]提出一种可快速计算船舶兴波阻力的复合算法,利用Rankine源格林函数求解船体表面源强,结合Lagally定理进行受力计算,并基于Kelvin源格林函数求解船舶兴波阻力。运用该算法对Wigley船的兴波阻力进行计算。[结果]计算结果表明,所用算法相较于运用线性兴波阻力中的薄船理论得到的结果精度更高,而且与完全使用Kelvin源格林函数的算法相比效率也更高。[结论]所用算法可在计算兴波阻力时作为精度与效率之间的一种折中方法。

[Ojectives] At present, the Boundary Element Method （BEM） of wave-making resistance mostly uses a model in which the velocity distribution near the hull is solved first, and the pressure integral is then calculated using the Bernoulli equation. However, the process of this model of wave-making resistance is complex and has low accuracy. [Methods] To address this problem, the present paper deduces a compound method for the quick calculation of ship wave resistance using the Rankine source Green function to solve the hull surface＇s source density, and combining the Lagally theorem concerning source point force calculation based on the Kelvin source Green function so as to solve the wave resistance. A case for the Wigley model is given. [Results] The results show that in contrast to the thin ship method of the linear wave resistance theorem, this method has higher precision, and in contrast to the method which completely uses the Kelvin source Green function,this method has better computational efficiency. [Conclusions] In general, the algorithm in this paper provides a compromise between precision and efficiency in wave-making resistance calculation.