波流联合作用下的物体上的波浪绕射力

Wave Diffraction Forces on an Arbitrary Body in Waves and Current

本文研究了在波流联合作用下的任意三维物体的波浪绕射问题,建立了求解物体上的波浪绕射力的时域解理论模型。本文证明了对于任意三维物体,如果在自由面条件简化时,假设定常兴波势为有限量阶,则在波浪绕射力公式中,不存在含有绕射势的水线积分项。从数学上证明了水线积分项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。在此基础上,本文提出了在波流联合作用情况下,作用在物体上的绕射力与辅助辐射势之间的关系式,从而不须求解绕射势便可得到绕射力。

A diffraction problcm for a surface ship travcling at a constant forward speed in waves is studied by time-domain analysis. Diffraction force are described using the incident wave potential and the proposed auxiliary-radiation potential.Therefore the diffraction forces in time-domain are obtained without computing the diffraction potential.In this paper, it is mathematically proved that for an arbitrary floating body, the term of the waterline integral in the formula for computing diffraction forces will be eliminated, assuming the fluid disturbance due to steady forward motion is not small in free-surface condition. Physically the term of waterline integral is the result of interaction between the fluid disturbance due to steady forward motion and unsteady wave motion.The present method is a major step forward in the development of design and prediction tools for ship motions and loads with forward speed.