共查询到19条相似文献，搜索用时 203 毫秒
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建立了基于高阶Boussinesq水波方程的一维波浪破碎数值模型。基于一组具有二阶完全非线性特征的Boussinesq水波方程,建立了交错网格下的高精度差分格式,推导了适用于该组方程的永形波解析解,其和松弛造波技术相结合实现了数值波浪水槽中(强)非线性波浪的无反射入射。通过模拟封闭容器内水体晃动问题对数值格式进行了验证,通过模拟孤立波在斜坡海岸上的浅化过程说明了将方程从弱非线性发展到完全非线性的必要性。采用涡粘方法处理波浪破碎,利用物理模型实验数据,分析了模型中各波浪破碎参数对数值结果的影响并对参数进行了率定。应用该模型对规则波在斜坡海岸上的传播、变浅以及破碎过程进行了数值模拟研究,数值结果同实验数据吻合良好,验证了模型的有效性。 相似文献
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为了更好地研究近岸海域波生沿岸流,建立了基于高阶Boussinesq水波方程的波生沿岸流时域数值模型。控制方程在中等水深范围内具有较好的色散性和变浅作用性能,同时具有二阶完全非线性特征,适合描述近岸区域波浪强非线性运动。通过采用松弛造波方法实现了非线性波浪的无反射入射,采用周期性侧边界条件模拟开敞边界。通过数值试验,讨论了模型中主要参数对数值结果的影响。利用率定后的参数模拟了均匀坡度海岸上产生的沿岸流,通过和实验数据的对比验证了模型的准确性和适用性。利用模型数值模拟了不同波浪入射条件(包括周期、波高和波浪入射角度)对波生沿岸流的影响。 相似文献
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提出一种基于完全非线性Boussinesq方程的改进波浪破碎模型,用于模拟近岸浅水波浪破碎.模型借助水滚的概念,提出一种确定k方程紊动模式中紊动源项的计算公式,通过解k方程计算Boussinesq方程中的涡黏系数,实现对破碎波的模拟.岸边界采用窄缝法,使得模型可用于波浪爬坡的计算.用实验室实测波高和增减水资料对模型进行了验证,得到了一致的结果.紊动源、紊动动能以及紊动耗散率的计算结果表明:①在破波点处紊动源项值最大,随着波浪向岸边传播,逐渐减小;②破波点处,水平方向的对流和扩散在紊动能量输移中发挥重要作用;③岸边附近紊动源与紊动耗散接近平衡. 相似文献
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有别于国内现行广泛应用Navie-Stokes方程进行地质灾害涌浪的数值模拟技术,本文采用波浪理论对地质灾害涌浪波进行了分析。地质灾害涌浪波是非周期性波,并且有强烈的非线性,介于中等水波至浅水波之间;可用浅水波模型和Boussinesq模型进行数学描述。本文采用有限差分法的Boussinesq模型,以三峡库区龚家方崩滑体涌浪为例,模拟了涌浪波的传播和爬高问题。该模型能够计算形成涌浪瞬时河面、河面最大波高图、最大流速矢量图、最大爬坡和预警分布图。模拟计算结果与调查结果吻合非常好。这说明基于波浪理论的地质灾害涌浪分析方法精度较高,为涌浪的预测研究提供了一种新的研究方法。 相似文献
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波浪破碎是海岸工程所关注的关键水动力学问题之一,而波浪破碎的数值模拟技术的研究方兴未艾。高效的浅水方程基于静压假定,而通过引入动压项建立的完全非静压模型,可成功应用于色散水波的模拟。自由表面的捕捉采用的垂向坐标变换技术,较之VOF（Volume of Fluid）模型,计算效率较高。但垂向坐标变换不能模拟大曲率自由表面变形,即波浪破碎过程。对于破碎波的模拟,一种高效的模式分裂法应用至非静压模型,即在波浪破碎局部水域将模型分裂为静压模型和非静压模型,破碎波波峰附近退化至静压模型,并持续至波浪破碎结束再恢复为动压模型。通过典型算例,验证了模式分裂法的适用性及对于波浪破碎过程的模拟精度,鉴于模式分裂法对于波浪破碎过程的模拟未引入新的概化模型,计算效率较高,可应用于大尺度的海岸带波浪的变形、破碎及越浪的数值模拟。 相似文献
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基于波作用量守恒方程建立了波流共存场中多向随机波浪传播变形数学模型,模型中考虑了波浪绕射的影响和水流引起的波浪弥散多普勒效应,应用包含水流和地形影响的激破波模式计算波浪破碎的能量耗散,采用一阶上迎风有限差分格式离散控制方程。分别计算了有无近岸流情况下单向和多向随机波浪的波高分布,考虑水流影响的数值计算结果与物理模型实验数据吻合良好,比较分析表明,所建立的数学模型能够复演由于离岸流引起的波高增大,可用于波流共存场多向随机波浪传播变形的模拟和预报。 相似文献
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非线性波浪作用下海底管线-海床动力响应分析 总被引：1，自引：0，他引：1
确定波浪荷载作用下海底埋置管线和海床的响应是海底管线设计中的关键问题。目前大多数研究只是考虑了管线、海床在线性推进波作用下的响应,并没有考虑管线与海床之间的相互作用效应。采用接触摩擦理论,考虑管线与海床之间的相互作用效应,基于有限元方法研究了非线性波浪作用下海底埋置管线和多孔海床相互作用问题。数值计算结果表明,在计算中如果忽略波浪非线性项,既有可能低估海底管线内应力及管线周围海床中孔隙水压力,也有可能高估海底管线内应力及管线周围海床中孔隙水压力。 相似文献
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将国际上通用的SWAN波浪数值模式应用到渤海,以检验其适应性。通过对由风引起的波浪的增长和耗散作用源函数的实验研究,发现SWAN中所采用的Phillips线性增长部分的比例系数和波浪成长有较大的关系,此比例系数随摩擦速度变化(原模式取此系数为一常数)。基于模式试验,引入了一个新的Phillips线性增长项公式,并且利用3个风过程对模式的改进进行了验证。3个风过程的计算结果和实测值比较表明,计算结果在3个过程当中都得到了明显的改进。 相似文献
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Madhav L. Khandekar 《Natural Hazards》1994,9(1-2):125-153
The Grand Banks and the Scotian Shelf regions of the Canadian Atlantic often experience strong winds and high waves associated with the passage of intense storms during the winter months of December to March. These storm waves are identified as a major hazard to shipping, offshore exploration and other marine activities in eastern Canada.In this study, an operational spectral ocean wave model has been used to simulate sea-states associated with selected storm events in the Canadian Atlantic. The wave model operates on a grid (with grid spacing of about 111 km) which covers a major portion of the north Atlantic. A nested fine grid (with grid spacing of about 37 km) has been designed which covers the shelf regions of the Canadian Atlantic. The model employs deep-water physics over the coarse grid while over the fine grid shallow-water processes as represented by wave refraction, wave shoaling, bottom friction and wave number scaling are included. The wave model also includes, as an optional package, the third-generation source terms as represented by the nonlinear wave-wave interaction terms.For two selected storm events, the model generated sea-states are evaluated against available buoy data as well as against hand analyzed operational wave height charts over the northwest Atlantic. The evaluation shows that the various versions of the model can simulate the observed sea-states, reasonably well. The utility of the wave model in providing numerical guidance for offshore activities is briefly discussed. 相似文献
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This study investigates impacts of a wave farm on waves, currents and coastal morphology adjacent to the wave farm, which is located in the Southwest of England (the Wave Hub). In this study, we focus on the interaction between waves and tides due to the presence of the wave farm and its effects on wave radiation stresses, bottom shear stresses and consequently on the sediment transport and the coast adjacent to the wave farm, using an integrated numerical modelling system. The modelling system consists of the near-shore wave model SWAN, the ocean circulation model ROMS and a sediment transport model for morphological evolution. The results show that tidal elevation and tidal currents can have a significant effect on waves and that tidal forcing and waves have a significant effect on bottom shear stresses. Waves can impact on the processes related to the bottom boundary layer and mixing intensity in the water column. The wave farm has an impact on the gradients of radiation shear stresses and bottom shear stresses that modify current speeds and wave heights, which in turn impact on the near-shore sediment transport and the resulting morphological changes. Bed load transport rates show a decrease when the wave farm is present, even during storm conditions. The results highlight the importance of the interactions between waves and tides when modelling coastal morphology with presence of wave energy devices. 相似文献
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P N Ananth Rao V S N Tatavarti J Swain C V K Prasada Rao 《Journal of Earth System Science》1993,102(2):351-366
Directional wave data collected during an experiment at a location on the continental shelf of the south west coast of India
using a WAVEC buoy, have been analysed based on the technique of Kuiket al (1988). The observed wave spectra indicate that the wave field is composed of sea waves (with peaks around 0·18 and 0·23
Hz) travelling nearly in the wind direction (WNW-N), and lower frequency (0·09 Hz) swell waves from the South. The parameterization
of the wave directional spread shows that both local wind conditions and nonlinear wave-wave interactions control the shape
of the directional distribution. The directional distribution is generally bimodal in the transition region between sea and
swell and at higher frequencies when rapid changes in wind speed and direction occur. 相似文献
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This article focused on the research progress in the gravity wave analysis based on satellite measurements including MODIS, AIRS, AMSU, MLS, DNB, COSMIC,HIRDLS and SOFIE. Besides, a few ground-based observation results and numerical models were briefly introduced and some cases of joint applications of satellite observations with ground-based observations and numerical models in the gravity waves were listed. In general, the satellite remote sensing data play an important role in the study of the characteristics in near-space environment, which can be applied to analyze the scales of gravity waves induced by different sources, correlations between the instabilities and waves as well as their patterns, the impacts in the climate process, wave-wave interactions and wave-flow interactions with other data. 相似文献
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利用高阶边界元方法求解拉普拉斯方程,建立了模拟完全非线性聚焦波的时域数值模型,其中追踪流体自由表面的方法为满足完全非线性自由水面条件的半混合欧拉-拉格朗日方法,运用四阶Runga-Kutta方法计算每一时间步新的波面高度和速度势,同时通过入射边界给定速度的二阶Stokes解析解产生波浪,并应用镜像格林函数消除水槽两个侧面和底面上的积分。对不同波陡的聚焦波群在水槽中开展了物理模型实验,并把试验结果和数值结果进行了对比,两者吻合得很好,然后对非线性条件下聚焦波的特点进行了研究。 相似文献
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Cyclone-generated surface waves are simulated using state-of-art SWAN (Simulating WAves Nearshore) model coupled with hydrodynamic
model inputs. A severe cyclonic storm passed over the Arabian Sea during 4–9th November 1982 is selected from UNISYS track
records. The cyclone lasted for nearly 6 days and subsided with a land fall at Gujarat coast, west coast of India. In this
study, cyclonic wind fields are generated using a well-established relationship suggested by Jelesnianski and Taylor (1973). The associated water level variations due to storm surge and surge generated currents are simulated using POM (Princeton
Ocean Model). The outputs are one-way coupled with the wave model SWAN for simulating wave parameters off Gujarat, north-east
basin of Arabian Sea. An extensive literature review is carried out on the progress and methodology adopted for storm wave
modelling and analysis. The results presented in this paper reveal the severity of the storm event and would be highly useful
for assessing the extreme wave event/climate especially for the south coast of Gujarat. 相似文献
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近岸波浪的不对称特征对浅水区泥沙输运以及海岸结构物受波浪冲刷影响而引起的破坏都起着关键作用,而目前关于波浪不对称特征的研究多集中在正向传播方式上,没有考虑斜向传播的影响,因此,对斜向波浪在近岸传播过程中的波形不对称特征展开研究具有重要的意义。基于高阶Boussinesq水波方程建立了斜向入射波浪沿斜坡传播的数值模型,并利用该模型进行数值试验,模拟了入射波浪沿0°~75°不同方向的传播过程。通过对不同角度入射得到的结果进行比较,讨论了入射角度对波浪不对称特征的影响。结果表明:入射角度越大的波浪,其在变浅过程中的二阶谱以及波浪的偏度和不对称度参数也越小。说明随着波浪入射角度增大,其非线性相互作用程度会发生减弱,导致波浪的非线性特征增长趋势逐渐变缓。最后,给出了考虑斜向角度影响的波浪不对称特征参数经验公式。 相似文献
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为研究近浅海领域内海上风机大直径单桩基础周围的砂质海床在非线性荷载作用下的瞬时液化的稳定性,在OpenFOAM平台上建立波浪-单桩-海床三维数值模型(WSSI模型),采用olaFoam求解器求解RANS方程模拟波浪的非线性运动,将Biot方程作为海床模型的控制方程研究单桩周围海床的液化规律。对以往的数值解析结果和实验结果进行对比分析,验证本文建立三维波浪模型和海床模型的准确性和有效性。将建立的波浪-管桩-海床相互作用三维数值模型应用到实际工况中,对数值模型在实际工程中的海床响应进行分析评估。研究结果表明,单桩周围海床的孔隙水压力场和有效应力场在水深方向发生较大变化,在水平方向变化较小。在该工况下海床的最大液化深度可达到10 m,且在垂直于波浪运动方向的海床更容易发生液化,为实际工程预测海床液化提供一定的技术支持。 相似文献