【摘要】 通过对波动传递函数的逆傅里叶变换建立脉冲响应函数的解析表达式,在仅已知不规则波波面过程线的情况下,利用脉冲响应函数与已知波面序列的卷积求得不规则波的速度场,并计算不规则波浪序列引起的水质点速度、加速度。通过与线性波浪叠加法的对比验证了方法的正确性,并应用Morison方程计算小尺度圆柱上的不规则波浪力。对不规则波浪力进行频谱分析得到:在非线性较弱时,脉冲响应法求得的波浪力谱与线性谱分析法的波浪力谱较为接近。随着波浪非线性的增强,脉冲响应法求得的速度力谱与线性谱分析法相比峰值不断增大,在低频和高频处能量增多,在主要能量区的谱宽也不断增加,而惯性力谱与线性谱分析方法结果基本相同。更多还原

【Abstract】 An analytical expression of the impulse response function was presented by the inverse Fourier Transform of the transfer function.The velocity of irregular waves was gained by calculating the convolution of the time history of wave and the impulse response function,for the case where only the wave time history of irregular waves was known.By a comparison with the superposition method of the linear irregular waves,the proposed approach was verified and the irregular wave forces were calculated by using Morison equation.Results of spectrum analysis show that the spectrums of wave forces from the impulse response method are close to that of linear spectrum analysis method in condition of weak nonlinearity.For the velocity forces,with the increase of nonlinearity,the energy increase in the high and low frequency regions of spectrums and peak values continue to increase by using impulse response method.Meanwhile,the spectral width of the main energy region is also increased.For the inertial forces,the spectrums are in fact identical by using the two methods.更多还原