切片理论应用于双体船运动计算时的伪共振问题

用切片理论来计算双体船流体动力系数时，在一些离散的频率上出现了共振。本文采用在二维双体剖面之间的自由面条件中引进入工粘性的技术，既不违背双体之间存在自由面的物理事实，又能有效地克服上述伪共振现象。文中对双椭球体辐射问题的计算及其与三维源汇分布法结果的比较表明，改进后的切片法可有效地应用于双体船在波浪中的运动计算。

ON FALSE RESONANCE IN APPLICATION OF STRIP THEORY TO MOTION ESTIMATION FOR CATAMARANS

Resonance would happen at some discrete frequencies on applying the strip theory to the calculation of hydrodynamic coefficients of catamarans. The phenomenon is not intrinsic in the original 3-D problem itself but is derived by adopting the strip theory to reduce the 3-D problem to the 2-D ones. In the present paper, an artificial viscosity technique is introduced in the free-surface condition on the free-surface between the twin sections, by which the above mentioned false resonance can be effectively eliminated without being contrary to the physical fact of the existence of free-surface. The comparison of the results concerning the hydrodynamic coefficients for catamaran with twin parallel ellipsoids obtained by the present strip theory and the 3-D source-sink distribution method shows that the present improved strip approach can be effectively applied to the motion estimation of catamarans in waves.