【摘要】 本文研究了水面船舶(物体)在波浪中航行时的绕射问题,求得了有航速船舶绕射问题线性时域解的理论模型.提出了计算波浪绕射力的公式.对于细长形的船舶.作者给出了计算波浪扰动力的公式,使得在时域中有航速船舶波浪扰动力的计算,可以用辐射势和入射波势来表示,而不须求解绕射势.利用本文所提出的波浪扰动力公式.在求解波浪扰动力时,对于任意多的入射波频率,只要解算积分方程一从而大大节省了计算工作量。本文还证明了在波浪中航行的一般三维物体,如果在自由面条件简化时,假设定常兴波势为有限量价,则在波浪绕射力公式中,不存在水线积分项。从数学上证明了水线积分项在物理上反映了自由面条件中定常兴波势和不定常势之间的耦合效应。在算例中,运用本文导出的波浪扰动力公式对 Wigley 船型进行了波浪扰动力的求解,与试验结果和现有理论方法的数值结果进行了比较,吻合良好.本文还对各种参数的影响进行了讨论,对计算结果所反映的物理现象作了分析。更多还原

【Abstract】 A diffraction problem for a surface ship traveling at a constant forward speed in waves is studied by time-domain analysis.Diffraction forces are described according to the incident wave potential and the auxiliary-radiation potential corresponding to the motion in opposite direction.A proposed“D.Z.Z.formula”for computing wave exciting forces is presented,therefore the exciting forces in time-domain can be given without computing the diffraction potential.The resulting integral equations of the auxiliary -ra- diation potentials need to be solved only once for all incident wave frequencies,which saves CPU time greatly,so the results in the time-domain theory can be used in engi- neering for practical purpose. This paper also proves mathematically that for an arbitrary floating body,the term of the waterline integral in the formula for computing diffraction forces will be eliminat- ed,assuming the fluid-disturbances due to steady forward motion is not small in free- surface condition,physically the term of waterline integral is the result of interaction be- tween steady forward motion and unsteady wave motion. Comparisons are shown among the results of time-domain computations,conven- tional frequency-domain calculations and experiments,which validate and demonstrate the efficiency of the method and the proposed D.Z.Z.formula.更多还原