【摘要】 应用相位聚焦技术在船模拖曳水池生成了基于等波陡谱的聚焦波群,采用极点对称模态分解(Extreme-point Symmetric Mode Decomposition,ESMD)方法研究了不同组成波带宽、不同聚焦波幅的聚焦波群的演化特性,重点分析了破碎与非破碎工况聚焦波群波面升高时间历程模态函数的瞬时频率、瞬时振幅和总能量的演化特性,研究发现基于总能量演化的聚焦位置分析可以较为准确地识别非破碎聚焦波群的实际聚焦位置,可以有效地描述聚焦波群发生破碎后继续传播和聚焦的演化过程,这些发现有助于深入理解非线性瞬态聚焦波群的演化特性。更多还原

【Abstract】 Deepwater focused wave groups based on the constant wave steepness(CWS) spectrum were generated in a towing tank by means of phase-focusing technology. Characteristics of evolution of focused wave groups with different bandwidths and amplitude are investigated by employing the extreme-point symmetric mode decomposition(ESMD) method. Instantaneous frequency, instantaneous amplitude and total energy for the mode functions of the wave with and without breaking are analyzed respectively in detail. Based on characteristics of total energy evolution, the analysis is able to identify the actual focusing location of the non-breaking focused wave groups, and describe the propagation and focusing process effectively after the focused wave groups breaking These findings are helpful to deepen and enrich the understanding of evolution of nonlinear transient focused wave groups.更多还原