基于EEMD-HHT的近岸冲流带波浪非线性波动特征分析
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摘要
冲流带复杂水流运动特性是研究近岸带物质输运的关键,其中波要素的历时变化具有非平稳性、非对称性和多尺度变化等复杂非线性波动特性,分析其作用周期及趋势规律,对认识冲流带的复杂水沙动力过程至关重要。基于溃坝原理产生涌波,采用水槽试验对涌波作用下不同坡度下冲流带波浪非线性波动特征开展研究。结合EEMD和HHT方法对试验波要素数据进行统计分析,得出波浪归一化能量谱、边际谱和边际能量谱,并结合功率谱密度分析水体波动对岸滩作用的影响。结果表明,冲流带的波浪波能主要集中在低频处,约低于1 Hz。在该研究的3种试验工况下,沿着岸滩向岸方向冲流带断面最大瞬时能量会逐渐衰减,当水流分别作用2～3 s,3～5 s和3～6 s时接近波浪最大瞬时能量,对岸滩作用达到最大;岸滩坡度越陡,最大瞬时能量值出现的时间越早,对床面的作用越大。
The characteristics of complex water flow in the swash zone are the key to the study of material transport in the nearshore zone,in which the diachronic variation of wave elements has complex nonlinear wave characteristics of non-stationarity,asymmetry and multi-scale variation,and so on. The action period and trend law of the wave element were analyzed,it is very important in order to understand the complex dynamic process of water and sediment in the swash zone. Based on the dam-break principle,a flume experiment was carried out to study the nonlinear wave characteristics of the scour current belt under the action of the surge wave with different slope. EEMD and HHT methods were used to analyze the experimental wave data,and the normalized wave energy spectrum,marginal energy spectrum and marginal energy spectrum were obtained,and the influence of water fluctuation on shoreline was analyzed with power spectral density. The results show that the wave energy of the current zone is mainly concentrated at the low frequency,which is lower than 1 Hz. Under the three experimental conditions,the maximum instantaneous energy gradually decrease along the shoreline direction. The maximum instantaneous energy appears and the currents have the strongest effects on shoreline,when the currents act on the shoreline for 2-3 s,3-5 s and 3-6 s respectively. The steeper the slope of the beach is,the earlier the maximum instantaneous energy value appears,the greater the effect on the beach surface is.
The characteristics of complex water flow in the swash zone are the key to the study of material transport in the nearshore zone,in which the diachronic variation of wave elements has complex nonlinear wave characteristics of non-stationarity,asymmetry and multi-scale variation,and so on. The action period and trend law of the wave element were analyzed,it is very important in order to understand the complex dynamic process of water and sediment in the swash zone. Based on the dam-break principle,a flume experiment was carried out to study the nonlinear wave characteristics of the scour current belt under the action of the surge wave with different slope. EEMD and HHT methods were used to analyze the experimental wave data,and the normalized wave energy spectrum,marginal energy spectrum and marginal energy spectrum were obtained,and the influence of water fluctuation on shoreline was analyzed with power spectral density. The results show that the wave energy of the current zone is mainly concentrated at the low frequency,which is lower than 1 Hz. Under the three experimental conditions,the maximum instantaneous energy gradually decrease along the shoreline direction. The maximum instantaneous energy appears and the currents have the strongest effects on shoreline,when the currents act on the shoreline for 2-3 s,3-5 s and 3-6 s respectively. The steeper the slope of the beach is,the earlier the maximum instantaneous energy value appears,the greater the effect on the beach surface is.
引文
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[13]MILES J,BUTT T,RUSSELL P. Swash zone sediment dynamics:a comparison of a dissipative and an intermediate beach[J]. Marine Geology,2006,231(1):181-200.
[14]WRIGHT L D,SHORT A D. Morphodynamic variability of surf zones and beaches:a synthesis[J]. Marine Geology,1984,56(1):93-118.
[15]熊学军,郭炳火,胡筱敏,等. EMD方法和Hilbert谱分析方法的应用与探讨[J].黄渤海海洋,2002,20(2):12-21.XIONG Xuejun, GUO Binghuo, HU Xiaomin, et al.Application and discussion of empirical mode decomposition method and Hilbert spectral analysis method[J]. Journal of Oceanography of Huanghal&Bohai Seas,2002,20(2):12-21.
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[17]马玉祥.基于连续小波变换的波浪非线性研究[D].大连:大连理工大学,2010.
[18]HUANG N E,SHEN Z,LONG S R. The empirical mode decomposition and the Hilbert spectrum for nonlinear and nonstatio narytime series analysis[J]. Mathematical,Physical and Engineering Sciences,1998,454:903-995.
[19]吴耀祖.水波动力研究进展[J].力学进展,2001,31(3):327-343.WU Yaozu. Advances in water wave mechanics[J].Advances in Mechanics,2001,31(3):327-343.
[20]SCHMITT F G,HUANG Y,LU Z,et al. Analysis of velocity fluctuations and their intermittency properties in the surf zone using empirical mode decomposition[J]. Journal of Marine Systems,2009,77(4):473-481.
[21]SENTHILKUMAR R,ROMOLO A,FIAMMA V,F,et al.Analysis of wave groups in crossing seas using Hilbert Huang transformation[J]. Procedia Engineering,2015,116(1):1042-1049.
[22]HWANG P A,HUANG N E,WANG D W. A note on analyzing nonlinear and nonstationary ocean wave data[J].Applied Ocean Research,2003,25(4):187-193.
[23]李志强,陈子燊.海滩冲流带高频振动及碎波带波浪作用的模态分析[J].海洋学报,2008,30(2):161-168.LI Zhiqiang,CHEN Zishen. Analyses of modes existing in the high frequency fluctuations of beachface and wave actions in the surf zone[J]. Acta Oceanologica Sinica,2008,30(2):161-168.
[24]郭明威,倪世宏,朱家海,等.振动信号中的HHT/EMD端点延拓方法研究[J].振动与冲击,2012,31(8):62-66.GUO Mingwei,NI Shihong,ZHU Jiahai,et al. HHT/EMD end extension method in vibration signal analysis[J]. Jounal of Vibration and Shock,2012,31(8):62-66.
[25]WU Z, HUANG N E. Ensemble empirical mode decomposition:a noise-assisted data analysis method[J].Advances in Adaptive Data Analysis,2009,1(1):1-41.
[26]刘永强,李翠省,廖英英.基于EEMD和自相关函数峰态系数的轴承故障诊断方法[J].振动与冲击,2017,36(2):111-116.LIU Yongqiang,LI Cuixing,LIAO Yingying. Fault diagnosis method for rolling bearings based on EEMD and autocorrelation function kurtosis[J]. Jounal of Vibration and Shock,2017,36(2):111-116.
[27]YEH H H,GHAZALI A,MARTON I,et al. Experimental study of bore run-up[J]. Journal of Fluid Mechanism,1989,206(1):563-578.
[28]郭喜平,王立东.经典模态分解(EMD)新算法及应用[J].噪声与振动控制,2008,28(5):70-72.GUO Xiping,WANG Lidong. New algorithm of empirical mode decomposition(EMD)and its application[J]. Noise and Vibration Control,2008,28(5):70-72.
[29]许宝杰,张建民,徐小力,等.抑制EMD端点效应方法的研究[J].北京理工大学学报,2006,26(3):196-200.XU Baojie,ZHANG Jianmin,XU Xiaoli,et al. A study on the method of restraining the ending effect of empirical mode decomposition(EMD)[J]. Transactions of Beijing Institute of Technology,2006,26(3):196-200.
[30]NAKAMURA S,KATOH K. Generation of infragravity waves in breaking process of wave groups[C]∥23rd International Conference on Coastal Engineering, Coastal Engineering(Venice). New York:ASCE,1992.
[31]THORNTON E B. Energetics of breaking waves within the surf zone[J]. Journal of Geophysical Research,1979,84(8):4931-4938.
[32]RAUBENHEIMER B. Observations and predictions of fluid velocities in the surf and swash zones[J]. Journal of Geophysical Research:Oceans,2002,107(C11):1-7.
[33]卢晓东,刘艳霞,严立文.莱州湾西岸岸滩冲淤特征分析[J].海洋科学,2008,32(10):39-44.LU Xiaodong, LIU Yanxia, YAN Liwen. Analysis of character of beach erosion and accumulation in the west coast of Laizhou Bay[J]. Journal of Marine Sciences,2008,32(10):39-44.
[34]曹佳,茅志昌,沈焕庭.杭州湾北岸岸滩冲淤演变浅析[J].海洋学研究,2009,27(4):1-9.CAO Jia,MAO Zhichang,SHEN Huanting. A brief analysis of scour and silting of the tidal flats at the north bank of the Hangzhouwan Bay[J]. Journal of Marine Sciences,2009,27(4):1-9.
[35]蒋昌波,陈杰,程永舟,等.海啸波作用下泥沙运动——Ⅰ.岸滩剖面变化分析[J].水科学进展,2012,23(5):665-672.JIANG Changbo,CHEN Jie,CHENG Yongzhou,et al. Study of sediment transport by tsunami waves:beach profile evolution[J]. Advances in Water Science,2012,23(5):665-672.
[36]程永舟,潘昀,蒋昌波,等.破碎波作用下沙质海床床面形态变化试验[J].水科学进展,2014,25(2):253-259.CHENG Yongzhou,PAN Yun,JIANG Changbo,et al. An experimental study on profile changes of sandy seabed under breaking waves[J]. Advances in Water Science,2014,25(2):253-259.
[2]王扬圣,陈子燊,刘萌伟.基于希尔波特-黄变换的海滩碎波带水体波动特征分析[J].中山大学学报(自然科学版),2008,47(1):112-115.WANG Yangsheng,CHEN Zishen,LIU Mengwei. Analysis of water oscillations in beach-surf zone based on HilbertHuang transform[J]. Acta Scientiarum Naturalium Universitatis Sunyatseni,2008,47(1):112-115.
[3]严恺,梁其荀.海岸工程[M].北京:海洋出版社,2002.
[4]陈杰,蒋昌波,刘虎英,等.潜堤对破碎区至冲泻区水动力特性影响数值分析[J].水科学进展,2011,22(3):382-390.CHEN Jie,JIANG Changbo,LIU Huying,et al. Numerical analysis of surf and swash zone hydrodynamics under the influence of submerged breakwater[J]. Advances in Water Science,2011,22(3):382-390.
[5]ELFRINK B,BALDOCK T. Hydrodynamics and sediment transport in the swash zone:a review and perspectives[J].Coastal Engineering,2002,45(3):149-167.
[6]BROCCHINI M, BALDOCK T E. Recent advances in modeling swash zone dynamics:influence of surf-swash interaction on nearshore hydrodynamics and morphodynamics[J]. Reviews of Geophysics,2008,46(3):1-21.
[7]PULEO J A,BUTT T. The first international workshop on swash-zone processes[J]. Continental Shelf Research,2006,26(5):556-560.
[8]ALSINA J M,CACERES I. Sediment suspension events in the inner surf and swash zone. Measurements in large-scale and high-energy wave conditions[J]. Coastal Engineering,2011,58(8):657-670.
[9]JIANG C B, DENG B, HU S X, et al. Numerical investigation of swash zone hydrodynamics[J]. Science China Technological Sciences,2013,56(12):3093-3103.
[10]GUZA R T,THORNTON E B. Swash oscillations on a natural beach[J]. Journal of Geophysical Research Oceans,1982,87(C1):483-491.
[11]ALSINA J M,CACERES I,BROCCHINI M,et al. An experimental study on sediment transport and bed evolution under different swash zone morphological conditions[J].Coastal Engineering,2012,68(10):31-43.
[12]MASSELINK G, RUSSELL P. Flow velocities, sediment transport and morphological change in the swash zone of two contrasting beaches[J]. Marine Geology,2006,227(3):227-240.
[13]MILES J,BUTT T,RUSSELL P. Swash zone sediment dynamics:a comparison of a dissipative and an intermediate beach[J]. Marine Geology,2006,231(1):181-200.
[14]WRIGHT L D,SHORT A D. Morphodynamic variability of surf zones and beaches:a synthesis[J]. Marine Geology,1984,56(1):93-118.
[15]熊学军,郭炳火,胡筱敏,等. EMD方法和Hilbert谱分析方法的应用与探讨[J].黄渤海海洋,2002,20(2):12-21.XIONG Xuejun, GUO Binghuo, HU Xiaomin, et al.Application and discussion of empirical mode decomposition method and Hilbert spectral analysis method[J]. Journal of Oceanography of Huanghal&Bohai Seas,2002,20(2):12-21.
[16]COOLE J W,TUKEY J W. An algorithm for the machine calculation of complex flourier series[J]. Mathematies of Computation,1965,19:297-301.
[17]马玉祥.基于连续小波变换的波浪非线性研究[D].大连:大连理工大学,2010.
[18]HUANG N E,SHEN Z,LONG S R. The empirical mode decomposition and the Hilbert spectrum for nonlinear and nonstatio narytime series analysis[J]. Mathematical,Physical and Engineering Sciences,1998,454:903-995.
[19]吴耀祖.水波动力研究进展[J].力学进展,2001,31(3):327-343.WU Yaozu. Advances in water wave mechanics[J].Advances in Mechanics,2001,31(3):327-343.
[20]SCHMITT F G,HUANG Y,LU Z,et al. Analysis of velocity fluctuations and their intermittency properties in the surf zone using empirical mode decomposition[J]. Journal of Marine Systems,2009,77(4):473-481.
[21]SENTHILKUMAR R,ROMOLO A,FIAMMA V,F,et al.Analysis of wave groups in crossing seas using Hilbert Huang transformation[J]. Procedia Engineering,2015,116(1):1042-1049.
[22]HWANG P A,HUANG N E,WANG D W. A note on analyzing nonlinear and nonstationary ocean wave data[J].Applied Ocean Research,2003,25(4):187-193.
[23]李志强,陈子燊.海滩冲流带高频振动及碎波带波浪作用的模态分析[J].海洋学报,2008,30(2):161-168.LI Zhiqiang,CHEN Zishen. Analyses of modes existing in the high frequency fluctuations of beachface and wave actions in the surf zone[J]. Acta Oceanologica Sinica,2008,30(2):161-168.
[24]郭明威,倪世宏,朱家海,等.振动信号中的HHT/EMD端点延拓方法研究[J].振动与冲击,2012,31(8):62-66.GUO Mingwei,NI Shihong,ZHU Jiahai,et al. HHT/EMD end extension method in vibration signal analysis[J]. Jounal of Vibration and Shock,2012,31(8):62-66.
[25]WU Z, HUANG N E. Ensemble empirical mode decomposition:a noise-assisted data analysis method[J].Advances in Adaptive Data Analysis,2009,1(1):1-41.
[26]刘永强,李翠省,廖英英.基于EEMD和自相关函数峰态系数的轴承故障诊断方法[J].振动与冲击,2017,36(2):111-116.LIU Yongqiang,LI Cuixing,LIAO Yingying. Fault diagnosis method for rolling bearings based on EEMD and autocorrelation function kurtosis[J]. Jounal of Vibration and Shock,2017,36(2):111-116.
[27]YEH H H,GHAZALI A,MARTON I,et al. Experimental study of bore run-up[J]. Journal of Fluid Mechanism,1989,206(1):563-578.
[28]郭喜平,王立东.经典模态分解(EMD)新算法及应用[J].噪声与振动控制,2008,28(5):70-72.GUO Xiping,WANG Lidong. New algorithm of empirical mode decomposition(EMD)and its application[J]. Noise and Vibration Control,2008,28(5):70-72.
[29]许宝杰,张建民,徐小力,等.抑制EMD端点效应方法的研究[J].北京理工大学学报,2006,26(3):196-200.XU Baojie,ZHANG Jianmin,XU Xiaoli,et al. A study on the method of restraining the ending effect of empirical mode decomposition(EMD)[J]. Transactions of Beijing Institute of Technology,2006,26(3):196-200.
[30]NAKAMURA S,KATOH K. Generation of infragravity waves in breaking process of wave groups[C]∥23rd International Conference on Coastal Engineering, Coastal Engineering(Venice). New York:ASCE,1992.
[31]THORNTON E B. Energetics of breaking waves within the surf zone[J]. Journal of Geophysical Research,1979,84(8):4931-4938.
[32]RAUBENHEIMER B. Observations and predictions of fluid velocities in the surf and swash zones[J]. Journal of Geophysical Research:Oceans,2002,107(C11):1-7.
[33]卢晓东,刘艳霞,严立文.莱州湾西岸岸滩冲淤特征分析[J].海洋科学,2008,32(10):39-44.LU Xiaodong, LIU Yanxia, YAN Liwen. Analysis of character of beach erosion and accumulation in the west coast of Laizhou Bay[J]. Journal of Marine Sciences,2008,32(10):39-44.
[34]曹佳,茅志昌,沈焕庭.杭州湾北岸岸滩冲淤演变浅析[J].海洋学研究,2009,27(4):1-9.CAO Jia,MAO Zhichang,SHEN Huanting. A brief analysis of scour and silting of the tidal flats at the north bank of the Hangzhouwan Bay[J]. Journal of Marine Sciences,2009,27(4):1-9.
[35]蒋昌波,陈杰,程永舟,等.海啸波作用下泥沙运动——Ⅰ.岸滩剖面变化分析[J].水科学进展,2012,23(5):665-672.JIANG Changbo,CHEN Jie,CHENG Yongzhou,et al. Study of sediment transport by tsunami waves:beach profile evolution[J]. Advances in Water Science,2012,23(5):665-672.
[36]程永舟,潘昀,蒋昌波,等.破碎波作用下沙质海床床面形态变化试验[J].水科学进展,2014,25(2):253-259.CHENG Yongzhou,PAN Yun,JIANG Changbo,et al. An experimental study on profile changes of sandy seabed under breaking waves[J]. Advances in Water Science,2014,25(2):253-259.