共查询到20条相似文献，搜索用时 390 毫秒
1.
用60个波高仪组成2m×2m的方阵,同步测量波面过程,用Doppler声学流速仪获得了二维正向和斜向规则波、二维正向和斜向随机波以及三维随机波浪场中不同水深处的同步Euler水质点速度各方向分量的高精度的时间过程资料.以此为出发点,讨论了分段式造波机生成波浪的周期分布特征,发现三维随机波浪周期分布的μ值与二维随机波浪比较有明显增大的趋势.分别从速度合矢量方向与波向的吻合程度(对二维波浪)、"多点波面"组合与"波面-水质点速度"组合两种方式得到方向谱的吻合程度(对三维随机波浪)等不同角度,论证了分段式造波机产生的波浪的内外部结构的一致性. 相似文献
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海浪方向谱的现场观测与分析 总被引：3，自引：0，他引：3
方向谱是海浪的基本性质之一。本文在国内首次采用测波仪阵列法在渤海采油平台上成功地观测到海浪方向谱，给出了当地随波浪成长而变化的方向谱表达式。观测前采用数模和模型试验方法，对阵列的布置型式、测波仪间距和平台等对观测结果的影响，以及现有各种方向谱分析方法的精度等进行了对比分析，为提高观测精度，保证方向谱分析的质量提供了依据。 相似文献
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分段式造波机生成波的方法和特性 总被引：2，自引：0，他引：2
本文叙述了分段式造波机生成波的理论和方法，通过试验确定了造波板前过渡段的长度，研究了分段式造波机生成波浪的特性，并将规则波的试验结果与理论结果进行了比较，给出了有效实验区的范围，可供实际应用时参考。 相似文献
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多向随机波的实验室模拟 总被引：3，自引：2，他引：3
海浪是一种多向随机波。本文首先对常用的多向随机波的数值模拟方法——双迭加法进行改进,建议了频率方向对应法,并给出了合适的模拟参数。此法能产生比较符合实际的波浪。在此基础上论述了三维随机波的物理模拟方法,并对多向随机波试验中的几个重要问题进行了探讨。 相似文献
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多向不规则波浪生成的数值方法 总被引：4，自引：3，他引：4
实际的海浪是三维(多方向)的,海浪的方向分布对于海浪折射、绕射及泥沙运动等的研究具有重要的意义,因而人们利用多向不规则造波机对它进行物理模型试验研究.同时,基于合适的数学模型,可在计算机上产生长时段的多向不规则波浪,用于研究海浪的基本特性及其对工程建筑物的作用,也是一种方便经济有效的手段,这也是制作多向不规则波造波机控制信号的基础.因此,如何由数模有效地合成多向不规则波浪,日益受到人们的重视.常用的一种方法是把海浪看作由无数不同频率和不同方向的组成波线性叠加而成,因而将模拟二维波浪的方法[1]直接推广应用于三维波浪的模拟.但是这样模拟所得的波浪往往是空间上不均匀,时间上会重复出现,需要进一步研究改进.本文首先给出了多向不规则波的三种模拟方法,并对其模拟结果进行了分析检验,给出了较理想的海浪模式.在此基础上,研究了模拟所得波浪的基本特征和模拟参数的确定. 相似文献
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本文对大窑湾海域观测的波浪资料(1985-06～1986-05,使用ENDECO 956型测波浮标)进行了分析。计算了平均方向、长峰系数和平均散角等方向特征参数,讨论了这些参数的特性和相互间的关系。研究了由观测资料获得的方向集中度参数S与风的关系以及与波-波间相互作用的关系,给出了它们之间的经验表达式,即方向函数,从而提出了该海域的方向谱形式。 相似文献
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多向不规则波有效试验区的扩展法 总被引：3，自引：2，他引：3
实验室中一般采用分段式造波机来产生斜向或多向波，但其中存在几个问题，最主要的是有效试验区较小。扩大有效试验区的常用方法是采用边墙反射法。本文首先叙述了应用边墙反射产生斜向波和多向波的方法，通过物理模型试验对该方法进行了验证，试验结果表明采用边墙反射的确可以扩大有效试验区的范围。 相似文献
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Satellite-based RAR performance simulation for measuring directional ocean wave spectrum based on SAR inversion spectrum 总被引：1，自引：0，他引：1
Some missions have been carried out to measure wave directional spectrum by synthetic aperture radar (SAR) and airborne real aperture radar (RAR) at a low incidence. Both them have their own advantages and limitations. Scientists hope that SAR and satellite-based RAR can complement each other for the research on wave properties in the future. For this study, the authors aim to simulate the satellite-based RAR system to validate performance for measuring the directional wave spectrum. The principal measurements are introduced and the simulation methods based on the one developed by Hauser are adopted and slightly modified. To enhance the authenticity of input spectrum and the wave spectrum measuring consistency for SAR and satellite-based RAR, the wave height spectrum inversed from Envisat ASAR data by cross spectrum technology is used as the input spectrum of the simulation system. In the process of simulation, the sea surface, backscattering signal, modulation spectrum and the estimated wave height spectrum are simulated in each look direction. Directional wave spectrum are measured based on the simulated observations from 0° to 360°. From the estimated wave spectrum, it has an 180° ambiguity like SAR, but it has no special high wave number cut off in all the direction. Finally, the estimated spectrum is compared with the input one in terms of the dominant wave wavelength, direction and SWH and the results are promising. The simulation shows that satellite-based RAR should be capable of measuring the directional wave properties. Moreover, it indicates satellite-based RAR basically can measure waves that SAR can measure. 相似文献
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针对由多点波面资料进行方向谱分析过程中发现的问题，利用数值模拟的方法研究了互谱分析中光滑点数，光滑次数，采样长度，采样间隔，波浪入射方向，波浪的多向性等因素对方向谱分析结果的影响，得出一些有意义的结论。 相似文献
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波浪谱分析是研究随机波浪、构建波浪模型、计算海浪要素的主要方法,也是海洋工程设计、波浪能应用研究等的重要依据。目前对于现场波浪数据的获取仅局限于波浪特征参数和部分频段数据,为了获取准确有效的波浪谱信息,提出微机电系统(Micro-Electro-Mechanical System,MEMS)和全球定位系统(Global Positioning System,GPS)测波传感器相结合的波浪谱数据获取方法以及利用北斗短报文数据传输的通信方式。综合考虑波浪谱数据特点和北斗短报文通信能力,波浪谱数据选用半精度数据类型编码并设计了相应的数据传输格式。现场海试结果表明该方法对于全波谱数据计算和传输较为准确,有效波高、峰值周期、平均波向和方向扩展的准确率相比于单独GPS传感器计算结果分别提升了12.5%(0.1m)、5%(0.2s)、8%(13°)和13%(8°),为海浪观测资料获取提供了新方法和新思路,可以进一步满足海洋多要素研究和对完整频谱分析的实际应用需求。 相似文献
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《Coastal Engineering》1999,36(1):17-36
A time domain method is presented for analyzing simultaneous measurements of pressure and the horizontal components of velocity obtained beneath irregular multidirectional wave fields. This new method differs from the usual linear directional analyses applied to PUV data in two important aspects. First, the essential nonlinearity of the measured waves is not sacrificed to achieve a solution. Therefore, predictions of sea surface elevation and directional kinematics throughout the water column accurately portray the actual nonlinear character of the waves. Second, the analysis method is `local' in that it can be applied to segments of PUV time series much shorter than an individual wave. The viability of the locally nonlinear methodology developed in this paper is proven by demonstrating agreement with higher-order theoretical steady waves. Predictions of sea surface elevation and wave kinematics are also made using actual measurements from PUV instruments at two ocean sites off the west coast of the United States. 相似文献
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风浪方向分布模式的比较 总被引：2，自引：0，他引：2
本文对目前常用的几种风浪方向分布模式进行了分析对比，进而根据由浪高仪阵列和ＥＮＤＥＣＯ９５６测波浮标在我国各海区测得的风浪方向谱，从波能方向分布、方向累积分布、方向分布的峰值和标准差四个方面，与光易恒、Ｈａｓｓｅｌｍａｎｎ和Ｄｏｎｅｌａｎ等分别由观测得到的经验方向分布以及文圣常等由解析方法得到的风浪方向谱进行了比较，结果表明：Ｄｏｎｅｌａｎ分布与实测结果比较一致，文圣常谱也较接近。此外，笔者在渤海由仪器阵列实测方向谱拟合得到的方向分布（改进的光易模式）与各地实测资料也比较符合。 相似文献
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The form of Boussinesq equation derived by Nwogu （1993） using velocity at an arbitrary distance and surface elevation as variables is used to simulate wave surface elevation changes. In the numerical experiment, water depth was divided into five layers with six layer interfaces to simulate velocity at each layer interface. Besides, a physical experiment was carried out to validate numerical model and study solitary wave propagation.“Water column collapsing”method （WCCM） was used to generate solitary wave. A series of wave gauges around an impervious breakwater were set-up in the flume to measure the solitary wave shoaling, run-up, and breaking processes. The results show that the measured data and simulated data are in good agreement. Moreover, simulated and measured surface elevations were analyzed by the wavelet transform method. It shows that different wave frequencies stratified in the wavelet amplitude spectrum. Finally, horizontal and vertical velocities of each layer interface were analyzed in the process of solitary wave propagation through submerged breakwater. 相似文献
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Use of nautical radar as a wave monitoring instrument 总被引：2，自引：0，他引：2
Common marine X-Band radars can be used as a sensor to survey ocean wave fields. The wave field images provided by the radars are sampled and analysed by a wave monitoring system (called WaMoS II) developed by the German research institute GKSS. This measuring system can be mounted on a ship, on offshore stations or at coastal locations. The measurement is based on the backscatter of microwaves from the ocean surface, which is visible as ‘sea clutter' on the radar screen. From this observable sea clutter, a numerical analysis is carried out. The unambiguous directional wave spectrum, the surface currents and sea state parameters such as wave periods, wave lengths, and wave directions can be derived. To provide absolute wave heights, the response of the nautical radar must be calibrated. Similar to the wave height estimations for Synthetic Aperture Radars, the so-called ‘Signal to Noise Ratio' leads to the determination of the significant wave height (HS). In this paper, WaMoS II results are compared with directional buoy data to show the capabilities of nautical microwave radars for sea state measurements. 相似文献
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Liu Shuxue Yu Yuxiu
Assistant Researcher State Key Laboratory of Coastal Offshore Engineering Dalian University of Technology 《中国海洋工程》1995,(1)
The directional spectrum is one of the basic characteristics of sea waves. The observations of directional spectrum of sea waves were successfully conducted at platform Bohai 8 during 1991 and 1992 using a wave gage array for the first time in China. Based on the field data, the directional spectrum which depends on the wave growth is given in this paper. Before observations, the effects of the type of gage array, the distance between the gages and the platform itself on the measured results and the precision of some methods for estimating the directional spectrum were investigated and compared with the methods of numerical simulations and model tests of multi-direcitonal irregular waves. This ensures the quality of the observations and estimations of the directional spectrum. 相似文献
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改进了方向波谱的分析方法及噪声谱经验公式，使本法随测波环境及仪器特性自动修正经验参值，更易于实际应用。基于Maximum heave/pitch quad-spectrum method，由时域及频率域上的浮标动力反应数值计算，推求反应增益因子及相位延迟项，并进一步将其导入方向波谱计算，使其能修正资料浮标对波浪之轴不对称动态反应所造成的相位延迟不一致及主波向误差。经数值仿真验证，该方法的确能消减因资料浮标对波浪之轴不对称动态反应所造成的相位延迟及对主波向估算所造成之影响。应用花莲现场观测资料验证改良之主波向估算方法，得出是否考虑波浪运动与浮标运动间之振幅响应因子及相位延迟因子，所得之主波向的差异介于0－12℃之间。 相似文献