利用满足自由表面条件的时域格林函数求解波浪与浮体相互作用问题时，对于外飘型浮体计算结果时常发散。针对此问题，建立了内外场时域快速匹配边界元模型，通过与解析解对比，验证了数值模型的有效性。其次，利用所建立的匹配边界元模型，研究了流场记忆速度势随时间的变化特点。针对长时间模拟，时间卷积积分项导致模拟失败问题，提出了利用Laguerre函数对记忆速度势时间变量进行级数逼近，以对时间卷积积分进行解析计算，并对级数收敛速度进行了研究。最后，为加快级数收敛速度，引入了放缩系数，并对其特性进行了探讨。数值结果表明，通过引入放缩系数，可以利用较少的级数项来逼近速度势的时间变量，能够很好地描述记忆速度势的脉冲特性。%The divergence phenomenon will happen when the transient free surface Green function method is adopt⁃ed to simulate the motion response of the ships with large flare. To avoid that problem, the Rankine⁃Green panel method is proposed , and the accuracy of this method is verified by the comparision with the analytical solutions. Then the hybrid method is used to investigate the variation properties of the memory velocity potential wiht respect to time, and the Laguerre function is introduced to express the memory potentials in the Laguerre series form. Therefore , the temporal convolution integral of the memory potentials with the Green function can be computed ana⁃lytically, which ensures the long time simulations. Besiedes, to accelerate the convergence speed of the Laguerre series, a flexible parameter is introduced and its features are discussed. The numerical results show that the tempo⁃ral variable of the memory potential can be approximated by less Laguerre series terms with a flexible parameter, which means that the Laguerre series can give a reasonable description of the impulse properties of the memory ve⁃locity potential.
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