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Effect of Nonlinearity on Groupiness of Random Wave Fields

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China Ocean Engineering 1999年第4期14卷 459-466页

作者：于定勇徐德伦郑建国 Engineering School Ocean University of Qingdao Qingdao 266071 China Physical Oceanology Laboratory Ocean University of Qingdao Qingdao 266071 China

Theoretical studies so far on random wave groups have all been in Linear ways. Methods to simulate random wave groups, an important subject in ocean engineering, also employ relationship resulting from a Gaussian process. Many filed measurements have shown that the real sea surface displacement deviates somewhat from Gaussian distribution. Tayfun et al, have further depicted in theory that the envelope spectral peak frequency is constantly zero for a Gaussian process which means that the groupiness factors will be constants, too. In this paper, the effect of nonlinearity on groupiness of a random wave field is examined via the theoretical results derived by Tayfun et al. from an expression of amplitude-modulated Stokes waves. When the surface displacement is treated as a non-Gaussian process, it is found that the group height factors GF(1) and GF(2) proposed by Zhao et al. and Yu et al., respectively, depend on a nonlinearity factor as well as a spectrum-bandwidth factor, deferring from the case of a Gaussion process. Comparison between the theoretical results and the field data shows a favorable agreement in consideration of errors from instrumentation and measuring means. The significance of the results is also discussed.

关键词： groupiness factor wave envelope nonlinearity

On the Bandwidth Parameter of Wind-Wave Spectra

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China Ocean Engineering 1999年第4期14卷 443-452页

作者：刘学海郑桂珍徐德伦 Physical Oceanography Laboratory Ocean University of Qingdao Qingdao 266003 China

In Light of the analysis of the physical implication and underlying assumption of the bandwidth parameter epsilon of wave spectrum, a time-averaging method is used to evaluate epsilon of the JONSWAP spectrum for different sea states. The resulting values of epsilon, which vary from 0.44 to 0.53 depending on the dimensionless fetch, are physically meaningful and reasonable. The same method is also used to compute epsilon from wind-wave records measured in a flume under different wind speeds at different fetches. The computed values of epsilon, which vary with wind fetches and speeds too, are compared with those evaluated for the JONSWAP spectrum.

关键词： sea-wave spectra spectral bandwidth microscale averaging

A Maximum-Entropy Compound Distribution Model for Extreme Wave Heights of Typhoon-Affected Sea Areas

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China Ocean Engineering 2012年第1期26卷 49-58页

作者：王莉萍孙效光吕可波徐德伦 College of Mathematical Science Ocean University of China College of Physical and Environmental Oceanography Ocean University of China

A new compound distribution model for extreme wave heights of typhoon-affected sea areas is proposed on the basis of the maximum-entropy principle. The new model is formed by nesting a discrete distribution in a continuous one, having eight parameters which can be determined in terms of observed data of typhoon occurrence-frequency and extreme wave heights by numerically solving two sets of equations derived in this paper. The model is examined by using it to predict the N-year return-period wave height at two hydrology stations in the Yellow Sea, and the predicted results are compared with those predicted by use of some other compound distribution models. Examinations and comparisons show that the model has some advantages for predicting the N-year return-period wave height in typhoon-affected sea areas.

关键词： maximum entropy principle typhoon occurrence-frequency N-year return period wave heights maximumentropy compound distribution

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二维海浪波包跨水平特征量及其应用

海洋学报 2003年第2期25卷 18-24页

作者：郑桂珍范海梅徐德伦中国海洋大学物理海洋实验室山东青岛266003

将Adler关于二维随机波场跨水平特征量的理论应用于二维线性随机海浪,严格导出了二维海浪波包的跨水平特征量表达式,并利用该式讨论了给定时刻二维海浪的一种几何结构——大波簇集情况。对于海面上波高均超过较高参考水平的一簇大波,给... 详细信息

将Adler关于二维随机波场跨水平特征量的理论应用于二维线性随机海浪,严格导出了二维海浪波包的跨水平特征量表达式,并利用该式讨论了给定时刻二维海浪的一种几何结构——大波簇集情况。对于海面上波高均超过较高参考水平的一簇大波,给出了一个计算其中波峰平均个数的公式,它与Glazman所给出的公式不同另外还给出计算上述大波簇平均面积的公式。最后结合现有的海浪万向谱给出一些具体计算结果,并对这些结果进行了讨论。

关键词：二维海浪几何结构波包

由JONSWAP谱和PM谱计算的风浪波高之间的关系

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海洋湖沼通报 1987年第1期 1-4页

作者：徐德伦山东海洋学院

一、序言 60年代中期以后,PM（Pierson-Moscowitz）谱在海浪研究及有关的工程问题中得到广泛的应用。众所周知,PM谱是由充分成长的风浪观测谱拟合而得到的,它代表充分成长的风浪。70年代中,根据JONSWP（Joint North Sea Wave Project）... 详细信息

一、序言 60年代中期以后,PM（Pierson-Moscowitz）谱在海浪研究及有关的工程问题中得到广泛的应用。众所周知,PM谱是由充分成长的风浪观测谱拟合而得到的,它代表充分成长的风浪。70年代中,根据JONSWP（Joint North Sea Wave Project）观测的2,500个有限风区风浪谱并参照PM谱又提出了JONSWAP谱

关键词：无因次风区谱形风浪波高谱峰频率 JONSWAP PM

A Refined Method for Estimating the Annual Extreme Wave Heights at A Project Site

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海洋工程：英文版 2003年第1期17卷 21-32页

作者：徐德伦范海梅张军 Physical Oceanography Laboratory Ocean University of China

This paper presents a refined method for estimating the annual extreme wave heights at a coastal or offshore project site on the basis of the data acquired at some nearby routine hydrographic stations. This method is based on the orthogonality principle in linear mean square estimation of stochastic processes. The error of the method is analyzed and compared with that of the conventional method. It is found that the method is able to effectively reduce the error so long as some feasible measures are adopted. A simulated test of the method has been conducted in a large scale wind wave flume. The test results are in good agreement with those given by theoretical error analysis. A scheme to implement the method is proposed on the basis of error analysis. The scheme is so designed as to reduce the estimation error as far as possible. This method is also suitable to utilizing satellite wave data for the estimation.

关键词： annual extreme wave height estimation refined method simulated test

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海上结构物的Ringing现象

海岸工程 1997年第3期16卷 6-11页

作者：于定勇徐德伦李瑞杰青岛海洋大学 266003

介绍近年来新发现的海上结构物在高海况下遇到的一种现象─—ringing高频共振响应现象及这一现象现有的研究成果，包括该现象的发现过程、特征、产生的机理及研究方法等。提出了研究ringing现象的一种可能的新方法。

关键词： ringing 高频共振响应海上结构物海上石油平台

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白浪覆盖率模式中参量的研究

海洋与湖沼 2009年第1期40卷 8-11页

作者：于定勇刘华兴李晶李翠琳徐德伦中国海洋大学工程学院青岛266100 DHI-NTU Water & Environment Research Center School of Civil and Environmental EngineeringNanyang Technological Universitysingapore639798 中国海洋大学海洋环境学院青岛266100

在波面位移为正态过程的假定下,推导出一种以平均周期和风速为参量的白浪覆盖率公式W=1-Φ〔5.11094〔T/U10〕0.7576〕。依据摩擦风速和U10的表达式,进一步推导出白浪覆盖率依赖于摩擦风速的形式W=1-Φ〔0.5227〔T/U*〕0.7576〕。考虑... 详细信息

在波面位移为正态过程的假定下,推导出一种以平均周期和风速为参量的白浪覆盖率公式W=1-Φ〔5.11094〔T/U10〕0.7576〕。依据摩擦风速和U10的表达式,进一步推导出白浪覆盖率依赖于摩擦风速的形式W=1-Φ〔0.5227〔T/U*〕0.7576〕。考虑到在实际应用中,经常需要用波龄描述波浪的状态,将白浪覆盖率表示成一种形式简单的波龄的函数W=1-Φ(3.6496ξ0.7576),与Monahan等的海上测量数据符合良好。

关键词：白浪覆盖率风浪破碎概率摩擦风速波龄

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海浪的特征波陡

海岸工程 1999年第3期18卷 5-12页

作者：郑桂珍徐德伦刘学海青岛海洋大学山东青岛266003

在现有的海浪要素统计分布的理论框架下具体地推导了二维海浪波高与波长的联合统计分布、波长统计分布以及波陡的统计分布。在此基础上对特征波陡的定义及其随风要素的变化规律做了较为细致的讨论。

关键词：波长波陡特征波陡统计分布海浪