共查询到20条相似文献，搜索用时 15 毫秒
1.
基于加密的非结构三角网格,以Holland模型风场叠加美国国家环境预报中心（NCEP）海面风场构造的合成风场驱动第三代浅水波浪数值模型（SWAN）对2017年影响闽东海域的“纳沙”和“泰利”台风过程进行数值模拟,并运用浮标站的实测数据对模拟结果进行验证.结果表明,模型计算的风速、有效波高与实测值符合较好,合成风场能较好地模拟台风期间的风速变化过程,SWAN模式能够合理地再现闽东沿海台风浪的时空分布特征.由模拟结果可见：台风“纳沙”中心越过台湾岛进入台湾海峡北部海面,受海峡地形的约束,其波浪场呈NE—SW向椭圆状分布,北部海域的浪高大于南部,闽东沿海遍布大范围的巨浪到狂浪;超强台风“泰利”未登陆闽东,当其台风中心与大陆的距离最近时,海面波浪场分布与台风风场结构一致,台风中心附近海域为14 m以上的怒涛区,巨浪遍布于闽东沿海.研究结果可为闽东沿海台风浪灾害预警和应急管理提供技术支撑和参考依据. 相似文献
2.
Effect of hydrodynamic properties of the sea bottom on the tidal dynamics in a rectangular basin 总被引：1，自引：0，他引：1
Expressions derived for the friction coefficient in an oscillatory rotating turbulent bottom boundary layer (BBL) over rough, incompletely rough (smoothly rough), and smooth underlying surfaces are incorporated as an individual module into a two-dimensional nonlinear tidal model, and the standard version of the model and its modified analogue are used to discuss the titular subject. It is established that the dynamics of tides in the Taylor basin can change noticeably under the effect of hydrodynamic properties of the sea bottom. Such changes occur mainly in the influence domains of amphidromies. In the remaining parts of the basin, relative changes in the amplitudes and phases of tidal sea-surface level elevations do not exceed ±10% and ±10°, respectively. The largest discrepancies of tidal characteristics take place in the cases of the incompletely rough and smooth sea bottoms; the smallest discrepancies, in the case of the rough sea bottom. Estimates for the changes in tidal characteristics that are caused by the usually neglected effects of rotation and phase difference between the bottom friction and the tidal velocity at the upper BBL boundary are presented as well. 相似文献
3.
《Coastal Engineering》2001,43(2):131-148
Four different expressions for wave energy dissipation by bottom friction are intercompared. For this purpose, the SWAN wave model and the wave data set of Lake George (Australia) are used. Three formulations are already present in SWAN (ver. 40.01): the JONSWAP expression, the drag law friction model of Collins and the eddy–viscosity model of Madsen. The eddy–viscosity model of Weber was incorporated into the SWAN code. Using Collins' and Weber's expressions, the depth- and fetch-limited wave growth laws obtained in the nearly idealized situation of Lake George can be reproduced. The wave model has shown the best performance using the formulation of Weber. This formula has some advantages over the other formulations. The expression is based on theoretical and physical principles. The wave height and the peak frequency obtained from the SWAN runs using Weber's bottom friction expression are more consistent with the measurements. The formula of Weber should therefore be preferred when modelling waves in very shallow water. 相似文献
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5.
In order to investigate surf zone hydrodynamics through two-dimensional numerical simulations of nearshore circulation under random wave environment, a nearshore circulation model, SHORECIRC, and a random wave model, SWAN, were combined and utilized. Using this combined model, a numerical simulation of the October 2, 1997 SandyDuck field experiment was performed. For this simulation, field topography and an input offshore spectrum were constructed using observed data sets synchronized with the experiment. The wave-breaking model in SWAN was modified by using breaker parameters varied according to bottom slope. The simulation results were compared with the experimental data, which revealed a well-developed longshore current, as well as with results using other combinations which were SHORECIRC and its original monochromatic wave-driver, and SHORECIRC and the default of SWAN. The results from the novel combined model agreed well with the experimental data. The results of the present simulation also indicate that alongshore field topography influences shear fluctuation of longshore currents. 相似文献
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7.
Dag Myrhaug 《Ocean Engineering》1982,9(6):547-565
An analytical theory which describes the motion in a turbulent wave boundary layer near a rough sea bottom by using a two-layer time invariant eddy viscosity model is presented. The eddy viscosity in the inner layer increases quadratically with the height above the sea bottom. In the outer layer the eddy viscosity is taken as a constant. The mean velocity and shear stress profiles, the bottom shear stress and the bottom friction coefficient are presented, and comparisons are made with experimental results. 相似文献
8.
Chitra Arora B. Prasad Kumar Indu Jain Ashoke Bhar A. C. Narayana 《Marine Geodesy》2013,36(2-3):261-281
The development of a theoretical model for estimating bottom boundary layer characteristics in the Hooghly estuary, located in the east coast of India, under combined effects of waves and currents is reported. Three numerical models, viz a depth averaged hydrodynamic model, SWAN wave model, and bottom boundary layer model, were integrated. In the bottom boundary layer parameters, maximum bottom stress, effective friction factor, and near-bed velocity both during ebb and flood phases of the tidal forcing are investigated and validated for the Haldia channel. The close match seen from results signifies applicability of this model for entire Hooghly basin. 相似文献
9.
Numerical study of three-dimensional wave-induced longshore current's effects on sediment spreading of the Huanghe River mouth 总被引：1，自引：0，他引：1
A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED,which has been developed through introducing wave-enhanced bottom shear stress,wave dependent surface drag coefficient,wave-induced surface mixing,SWAN,damping function of sediment on turbulence,sediment model and depth-dependent wave radiation stress to COHERENS.The COHERENS-SED is adopted to study the effects induced by wave-induced three-dimensional longshore current on suspended sediment spreading of the Huanghe River (Yellow River) mouth.Several different cases divided by setting different wave parameters of inputting boundary waves are carried out.The modeling results agree with measurement data.In terms of simulation results,it is easy to know that three-dimensional wave radiation stress plays an obvious role when inputting boundary wave height is stronger than 3 m.Moreover,wave direction also affects the sediment spreading rules of the mouth strongly too. 相似文献
10.
A study of marine breezes and their impact on the wave field around Mallorca Island was carried out by numerical simulations with the spectral wave model SWAN and three different wind fields: WRF – Weather Research and Forecasting model, HIRLAM – High Resolution Limited Area model and ECMWF – European Center for Medium-range Weather Forecasts. The main characteristics of the modelled breeze circulation and its effects on the wave field are analyzed. The modified wave field under breeze conditions and the correlations with their variability and daily short life time period are studied and discussed by analyzing the spectral balance. The results show that the accuracy of a wave forecast will depend on the quality of the wind field and its ability to simulate the sea breeze induced waves. The study period covers the summers of 2009 and 2010. In addition, to assess the performance of SWAN forced with two different winds the numerically obtained significant wave heights (Hs) are collocated against the ENVISAT-ESA's Environmental Satellite measurements (GLOBWAVE data) of Hs around the Mallorca Island. 相似文献
11.
Wave-tide-surge coupled simulation for typhoon Maemi 总被引：1，自引：0，他引：1
The main task of this study focuses on studying the effect of wave-current interaction on currents, storm surge and wind wave as well as effects of current induced wave refraction and current on waves by using numerical models which consider the bottom boundary layer and sea surface roughness parameter for shallow and smooth bed area around Korean Peninsula. The coupled system (unstructured-mesh SWAN wave and ADCIRC) run on the same unstructured mesh. This identical and homogeneous mesh allows the physics of wave-circulation interactions to be correctly resolved in both models. The unstructured mesh can be applied to a large domain allowing all energy from deep to shallow waters to be seamlessly followed. There is no nesting or overlapping of structured wave meshes, and no interpolation is required. In response to typhoon Maemi (2003), all model components were validated independently, and shown to provide a faithful representation of the system’s response to this storm. The waves and storm surge were allowed to develop on the continental shelf and interact with the complex nearshore environment. The resulting modeling system can be used extensively for prediction of the typhoon surge. The result show that it is important to incorporate the wave-current interaction effect into coastal area in the wave-tide-surge coupled model. At the same time, it should consider effects of depth-induced wave breaking, wind field, currents and sea surface elevation in prediction of waves. Specially, we found that: (1) wave radiation stress enhanced the current and surge elevation otherwise wave enhanced nonlinear bottom boundary layer decreased that, (2) wind wave was significantly controlled by sea surface roughness thus we cautiously took the experimental expression. The resulting modeling system can be used for hindcasting (prediction) the wave-tide-surge coupled environments at complex coastline, shallow water and fine sediment area like areas around Korean Peninsula. 相似文献
12.
A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN, damping function of sediment on turbulence, sediment model and depth-dependent wave radiation stress to COHERENS. The COHERENS-SED is adopted to study the effects induced by wave-induced three-dimensional longshore current on suspended sediment spreading of the Huanghe River (Yellow River) mouth. Several different cases divided by setting different wave parameters of inputting boundary waves are carried out. The modeling results agree with measurement data. In terms of simulation results, it is easy to know that three-dimensional wave radiation stress plays an obvious role when inputting boundary wave height is stronger than 3 m. Moreover, wave direction also affects the sediment spreading rules of the mouth strongly too. 相似文献
13.
黄河三角洲区域的波流相互作用数值分析 总被引：1，自引：0，他引：1
将三维水动力-生态模式COHERENS与第三代波浪模式SWAN结合起来,采用该耦合模式数值计算了黄河三角洲的波浪特征波高与特征周期情况,从而探讨水流和波动水位对波浪特征波高和特征周期计算结果的影响。总的说来特征波高、特征周期、流速的计算结果与观测值吻合得较好,说明了COHERENS模式和SWAN模式相结合而成的波流耦合模式能够较好地计算黄河三角洲地区的流场与浪场情况。研究这些动力因素的机制和时空变化规律,对于研究海岸、河口的泥沙运动,海岸侵蚀的机理,合理开发利用自然资源,防止海洋灾害具有十分重大的意义。 相似文献
14.
台风是影响中国黄东海的强天气现象,其引起的强风、巨浪和台风增水严重威胁着沿海地区人民的生命与财产安全。本文以海浪模式SWAN（Simulating Waves Nearshore）与区域海洋模式ROMS（Regional Ocean Modeling System）为基础,构建了中国黄东海海域在201509号台风“灿鸿”影响下的海浪-海洋耦合模式。通过浮标与Jason-2高度计有效波高数据验证了模式结果的准确性。进行了敏感性实验分析,对比耦合（ROMS+SWAN）与非耦合（SWAN）下以及使用不同地形数据（ETOPO1、ETOPO2、GEBCO）、不同物理参数化方案（风能输入、白冠耗散、底摩擦耗散）下的模拟结果差异。结果发现在射阳与前三岛浮标处,使用GEBCO地形数据（15弧秒间隔）下的模拟效果更好且稳定。在空间分布上,台风中心附近的浪流相互作用显著,在其前进方向右侧表现为耦合的有效波高值低于非耦合有效波高值,差值最高可达1米。选择不同风输入与耗散项方案时的模拟差异主要发生在最大波高处,选择不同的风能输入与白冠耗散项方案带来的差异接近0.4米,而底摩擦项方案选择不同带来的差异接近1米。因而在模拟实际的海况时,需要综合考虑这些因素带来的影响,才能达到SWAN海浪模型最好的海浪模拟效果。 相似文献
15.
WAVEWATCH和SWAN嵌套模拟台风浪场的结果分析 总被引：1，自引：0，他引：1
利用WAVEWATCH和SWAN嵌套模拟2007年8月墨西哥湾飓风迪安的波浪场.将QSCAT/NCEP混合风场与台风模型风场合成为背景风场.修改WAVEWATCH和SWAN嵌套接口以使WAVEWATCH和SWAN2种海浪预报模式能够有效地嵌套运行.利用WAVEWATCH和SWAN嵌套模拟飓风迪安的波浪场,采用浮标资料检验模拟结果,以验证WAVEWATCH和SWAN模拟的准确性及修改后嵌套接口的可用性.结果表明,修改嵌套接口之后模式运行平稳,2种模式的结果与浮标及高度计观测数据均基本吻合.嵌套模拟结果好于单纯使用WAVEWATCH模拟的结果,体现了利用2种模式嵌套模拟台风浪场的科学性. 相似文献
16.
SWAN模型中不同风拖曳力系数对风浪模拟的影响 总被引：1，自引：1，他引：0
本文以荷兰哈灵水道海域为实验区域,通过敏感性实验,研究了在14 m/s、31.5 m/s和50 m/s（分别代表一般大风、强热带风暴和强台风的极端条件）定常风速下SWAN模型中不同风拖曳力系数对风浪模拟的影响程度。结果表明,对于近岸浅水区域（水深小于20 m）,风拖曳力系数计算方案的选择对有效波高影响较小,而且当风速增加到一定程度后,波浪破碎成为影响波高值的主要因素;对于深水区域（水深大于30 m）,一般大风条件下风拖曳力系数计算方案的选择对有效波高影响仍然较小,随着风速的继续增大,风拖曳力系数计算方案的选择对有效波高的影响逐渐显著。对于平均周期,风拖曳力系数计算方案的选择和风速的改变对其影响均较小,而由水深变浅导致的波浪破碎对其影响较为显著。根据敏感性实验结果,本文对SWAN模型中风拖曳力系数计算方案的选择做出如下建议:计算近岸浅水区域风浪场或深水区域一般大风条件风浪场时,其风拖曳力系数可以直接采用模型默认选项;而对于深水区域更大风速条件,可首先采用模型默认选项试算,然后结合当地海域实测波浪资料进行修正。 相似文献
17.
This study investigates the effectiveness of a revised whitecapping source term in the spectral wind wave model SWAN (Simulating WAves Nearshore) that is local in frequency space, nonlinear with respect to the variance density and weakly dependent on the wave age. It is investigated whether this alternative whitecapping expression is able to correct the tendency towards underprediction of period measures that has been identified in the default SWAN model. This whitecapping expression is combined with an alternative wind input source term that is more accurate for young waves than the default expression. The shallow water source terms of bottom friction, depth-induced breaking and triad interaction are left unaltered. It is demonstrated that this alternative source term combination yields improved agreement with fetch- and depth-limited growth curves. Moreover, it is shown, by means of a field case over a shelf sea, that the investigated model corrects the erroneous overprediction of wind-sea energy displayed by the default model under combined swell-sea conditions. For a selection of field cases recorded at two shallow lakes, the investigated model generally improves the agreement with observed spectra and integral parameters. The improvement is most notable in the prediction of period measures. 相似文献
18.
The hydrodynamic performance of the oscillating water column type shoreline-mounted wave-power device is numerically studied within linear wave theory by using a boundary element method based on the Wehausen and Laitone 3D shallow water Green's function. In order to verify the numerical model, a 1:12 physical model with different bottom slopes was constructed and tested in a wave basin under regular wave conditions. The effects of the bottom slope on the hydrodynamic performance are investigated by both analytical and experimental methods. 相似文献
19.
Sea ice can attenuate wave energy significantly when waves propagate through ice covers.In this study,a third-generation wave model called simulating wave nearshore(SWAN)was advanced to include damping of wave energy due to friction in the boundary layer below the ice.With the addition of an eddy viscosity wave-ice model,the resulting new SWAN model was applied to simulate wave height in the Bohai Sea during the freezing winter.Its performance was validated with available buoy data near the ice edge,and the new model showed an improvement in accuracy because it considered the ice effect on waves.We then performed a wave hindcast for the Bohai Sea during a freezing period in the winter of 2016 that had the severest ice conditions in recent years and found that the mean significant wave height changed by approximately 16.52%.In the Liaodong Bay,where sea ice concentration is highest,the change reached 32.57%,compared with the most recent SWAN model version.The average influence of sea ice on wave height simulation was also evaluated over a five-year(2013-2017)hindcast during January and February.We found that the wave height decrease was more significant in storm conditions even the eddy viscosity wave-ice model itself showed no advantage on damping stronger waves. 相似文献