船体湿表面脉动压力预报的三维非线性方法

本文给出了一种预报船体湿表面脉动压力响应的三维非线性时历模拟方法.计及瞬时物面变化引起的各种非线性因素,在时域内建立船体非线性运动方程.在每一时刻,认为船体以其瞬时平均湿表面为平衡位置做简谐振荡运动,利用三维线性频域解来简化运算.在此基础上,进一步将绕射和辐射问题在静平衡位置求解,仅考虑占主导地位的入射波和静恢复力变化的非线性,作为一种兼顾工程需要的计算精度和计算效率的简化方法.以此方法为基础编制了计算机程序,对实船进行了计算,并与模型试验进行了对比.分析比较表明,该方法能够给出令人满意的船体湿表面脉动压力响应预报结果.

3-D nonlinear computational method of dynamic pressure on ship wetted surface

A three-dimensional nonlinear time history simulation method of dynamic pressure on ship wetted surface is presented in this paper.Considering the nonlinear factors due to the alteration of instantaneous body surface,the equations of nonlinear ship motions are established in time domain.At each time step,on the assumption that the ship is oscillating in harmonic mode with the instantaneous mean wetted surface as the balanced position,the three-dimensional linear frequency domain solutions will be applied to simplify the computation.Furthermore,on the basis of above,the diffraction and radiation problem are solved under still balanced position,and only consider the dominant nonlinear factors of incident wave forces and hydrostatic restoring forces,which are taken as the simplified method for the engineering needs of both accuracy and efficiency.A computer program based on this method was developed,and calculation examples were illustrated.Analysis results show that the method can give satisfying prediction of dynamic pressure responses on ship wetted surface.