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1.
By coupling the three-dimensional hydrodynamic model with the wave model, numerical simulations of the three-dimensional wave-induced current are carried out in this study. The wave model is based on the numerical solution of the modified wave action equation and eikonal equation, which can describe the wave refraction and diffraction. The hydrodynamic model is driven by the wave-induced radiation stresses and affected by the wave turbulence. The numerical implementation of the module has used the finite-volume schemes on unstructured grid, which provides great flexibility for modeling the waves and currents in the complex actual nearshore, and ensures the conservation of energy propagation. The applicability of the proposed model is evaluated in calculating the cases of wave set-up, longshore currents, undertow on a sloping beach, rip currents and meandering longshore currents on a tri-cuspate beach. The results indicate that it is necessary to introduce the depth-dependent radiation stresses into the numerical simulation of wave-induced currents, and comparisons show that the present model makes better prediction on the wave procedure as well as both horizontal and vertical structures in the wave-induced current field. 相似文献
2.
The prediction of near-shore morphology on the time scale of a storm event and the length scale of a few surf zone widths is an active area of research. Intense wave breaking drives offshore-directed currents (undertow) carrying sediment seawards, resulting in offshore bar migration. In contrast, higher order nonlinear properties, such as wave asymmetry (velocity skewness) and velocity asymmetry, are drivers for shoreward transport. These wave processes are included in phase-resolving models such as Boussinesq-type wave models (e.g., TRITON). Short-wave averaging in the wave model yields wave-induced forces (e.g., radiation stress gradients) and a wave asymmetry term. The wave-induced forces are used in a hydrostatic model (e.g., Delft3D flow module) to drive the current and undertow, resulting in a 3D velocity profile. The wave model and hydrostatic model are coupled online with a morphodynamic model (e.g., Delft3D morphology module). The latter computes, based on the 3D flow profile and the wave asymmetry term, the sediment transport and performs the bathymetry updates. The updates are transferred directly back to the hydrodynamic models. The coupling of the wave model TRITON and the Delft3D modules is validated by comparing against extensive laboratory data sets (LIP and Boers) and a field case (Duck94), and show a good performance for the hydrodynamics and a reasonable/fair performance for the bar movements. 相似文献
3.
The vertically-integrated effect of interaction between waves and wave-induced currents on wave transformation over a submerged elliptic shoal was investigated based on numerical simulations of the Vincent and Briggs experiment [Vincent, C.L., Briggs, M.J., 1989. Refraction- diffraction of irregular waves over a mound. Journal of Waterway, Port, Coastal and Ocean Engineering, 115(2), pp. 269–284.]. The numerical simulations were performed using two numerical wave-current model systems: one, a combination of the wave model SWAN and the current model SHORECIRC, and the other, a combination of the wave model REF/DIF and the same current model. A time-dependent, phase-resolving wave and current model, FUNWAVE, was also utilized to simulate the experiment. In the simulations, the developed wave-induced currents defocused waves behind the shoal and brought on a wave shadow zone that showed relatively low wave height distributions. For the breaking case of monochromatic waves, the wave heights computed using FUNWAVE showed good agreement with the measurements and the resulting wave-induced currents showed a jet-like velocity distribution in transverse direction. And the computed results of the two model combinations agreed better with the measurements than the computed results obtained by neglecting wave-current interaction. However, it was found that for the case in which transverse interference pattern caused by refracted waves was strong, REF/DIF-SHORECIRC did not correctly evaluate radiation stresses, the gradients of which generate wave-induced currents. SWAN-SHORECIRC, which cannot deal with the interference patterns, predicted a jet-like wave-induced current. For breaking random wave cases, the computed results of the two model combinations and FUNWAVE agreed well with the measurements. The agreements indicate that it is necessary to take into account the effect of wave-induced current on wave refraction when wave breaking occurs over a submerged shoal. 相似文献
4.
Yang Zhang Changsheng Chen Guoping Gao Jianhua Qi Huichan Lin Wei Yu Liang Chang 《海洋学报(英文版)》2021,40(11):129-137
In this paper, an ice floe inner stress caused by the wave-induced bending moment is derived to estimate the stress failure of ice floe. The strain and stress failures are combined to establish a wave-induced ice yield scheme. We added ice stress and strain failure module in the Finite-Volume Community Ocean Model (FVCOM), which already includes module of ice-induced wave attenuation. Thus a fully coupled wave-ice dynamical interaction model is established based on the ice and wave modules of FVCOM. This model is applied to reproduce the ice and wave fields of the breakup events observed during the second Sea Ice Physics and Ecosystem Experiment (SIPEX-2) voyage. The simulation results show that by adopting the combined wave-induced ice yield scheme, the model can successfully predict the ice breakup events, which the strain failure model is unable to predict. By comparing the critical significant wave height deduced from strain and stress failure schemes, it is concluded that the ice breakup is caused by the strain failure when wave periods are shorter than a threshold value, while the stress failure is the main reason for the ice breakup when wave periods are longer than the threshold value. Neglecting either of these two ice-break inducement mechanisms could overestimate the ice floe size, and thus underestimate the velocity of the ice lateral melt and increase the error of simulation of polar ice extent. 相似文献
5.
J.W. Dippner 《Coastal Engineering》1987,11(5-6)
A numerical model is presented, which investigates the contribution of wave-induced currents to the tidal residual circulation in the German Bight. The momentum transfer, by swell decaying to the mean circulation, is calculated including wave-current interaction without refraction. The model couples deep-water and shallow-water energy dissipation mechanisms such as wave attenuation and wave breaking. The model computes wave set-up, wave set-down and a longshore current as well. The pure wave-induced circulation is calculated, and also the residual circulation due to the interaction between waves and tide. The results suggest that the wave-induced currents can be neglected for the calculation of transport of near-surface pollutants. 相似文献
6.
非结构化网格下近岸波生流数值模拟 总被引：5，自引：2，他引：3
波浪破碎产生的近岸流是近岸海域关键的水动力因素之一。基于近岸波浪的椭圆型缓坡方程和二维近岸波生流方程,建立了非结构化网格下近岸波浪破碎形成的近岸流数值模型。数值模型中,在空间上采用有限体积法进行数值离散,在时间上采用欧拉向前格式数值离散。数值计算结果表明,该数值模型可以有效地模拟近岸波浪破碎产生的近岸流。 相似文献
7.
《Ocean Modelling》2011,39(3-4):230-243
A three-dimensional numerical model was established to simulate the wave-induced currents. The depth-varying residual momentum, surface roller, wave horizontal and vertical turbulent mixing effects were incorporated as major driving forces. A surface roller evolution model considering the energy transfer, roller density and bottom slope dissipation was developed. The expression of the wave-induced horizontal turbulent mixing coefficient proposed by Larson and Kraus (1991) was extended to three-dimensional form. Plenty of experimental cases were used to validate the established model covering the wave setup, undertow, longshore currents and rip currents. Validation results showed the model could reasonably describe the main characteristics of different wave-induced current phenomena. The incorporation of surface roller for breaking waves should not be neglected in the modeling of surfzone hydrodynamics. The wave-induced turbulent mixing affects the structures of wave-induced current either in horizontal or in vertical directions. Sensitivity analysis of the major calibration parameters in the established model was made and their ranges were evaluated. 相似文献
8.
基于三维潮流和谱波浪模型,以及输移扩散模型和拉格朗日粒子追踪模型,构建了波流耦合下保守污染物的迁移扩散模型。模型基于非结构化网格,对近岸复杂岸线有很好的拟合,可用于大范围波流耦合计算。运用所建的耦合模型研究了旅顺港内外的潮流变化、波生流场、保守污染物输移、粒子运动、以及新水道对湾内污染物迁移的影响,模拟的潮流场与实测数据吻合较好。结果表明:潮流会在湾内近湾口处形成一逆时针涡,波浪对湾内影响较小,但波生流会改变湾口流场分布;在湾内处于涡中的水体潮流自净能力较强,而湾中及湾底则较弱,SE向波浪会降低湾内水体的自净能力;新潮流通道的开挖,会显著改善水体的自净能力,尤其对湾底浅水区域作用明显。 相似文献
9.
根据现场地形在港池中建立三维珊瑚礁?潟湖?裂口海岸定床整体物理模型,采用波高传感器、流速仪和表面流速测量系统分别测量了规则波作用下珊瑚礁海岸不同位置的波浪和流场特征。结果表明:礁坪上,波高在向岸方向逐渐减小,总减小幅度为86.7%,增水先增大后减小,沿礁坪下降幅度为65.9%,水流以向岸流为主,存在着先增大后减小的趋势;潟湖中,波高靠近裂口处较大,中部最大值约为两侧最小值的2.8倍,增水则靠近裂口处最小,相比两侧最大值下降了25.5%,水流主要为对称地指向裂口的沿岸流,流速从两侧到裂口先增大后减小;裂口中波高变化不大,增水在靠近潟湖处最大,为礁坪上增水的47.6%,水流主要为离岸流,流速同样是先增大后减小。量化分析了环流驱动力、辐射应力与波面压力梯度的空间变化规律,发现礁坪上向岸流变化是平均水位梯度和辐射应力相互作用的结果,在裂口中的离岸流驱动力主要为辐射应力,而潟湖中的沿岸流变化由平均水位梯度决定的。 相似文献
10.
Numerical Simulation of Spatial Lag Between Wave Breaking Point and Location of Maximum Wave-Induced Current 总被引：2，自引：0，他引：2
A quasi three-dimensional numerical model of wave-driven coastal currents with the effects of surface rollers is developed for the study of the spatial lag between the location of the maximum wave-induced current and the wave breaking point.The governing equations are derived from Navier-Stokes equations and solved by the hybrid method combining the fractional step finite different method in the horizontal plane with a Galerkin finite element method in the vertical direction.The surface rollers effects are considered through incorporating the creation and evolution of the roller area into the free surface shear stress.An energy equation facilitates the computation process which transfers the wave breaking energy dissipation to the surface roller energy.The wave driver model is a phase-averaged wave model based on the wave action balance equation.Two sets of laboratory experiments producing breaking waves that generated longshore currents on a planar beach are used to evaluate the model's performance.The present wave-driven coastal current model with the roller effect in the surface shear stress term can produce satisfactory results by increasing the wave-induced nearshore current velocity inside the surf zone and shifting the location of the maximum longshore current velocity landward. 相似文献
11.
波浪增水和波生流是河口泥沙输运、地貌演变和污染物扩散的重要动力之一,但目前关于远区台风影响下长江口波浪增水和波生流的研究比较缺乏。本文建立了覆盖东中国海的台风-天文潮-波浪耦合三维数值模型,研究了远区台风“三巴”对长江口波浪增水和波生流的影响。结果表明:波浪从台风中心向近岸传播过程中,能量耗散引起波浪作用力的衰减和辐射应力的增大,产生波浪增水,长江口波浪增水在0.05 ~0.20 m之间,占台风总增水值的15%~22%。从NW向入射的台风浪产生自北向南的波生沿岸流,垂向上呈现三维结构,平均流速在0.05~0.20 m/s之间,占风暴潮流的15%~50%,充分说明了远区台风可以对长江口波浪增水和波生流产生明显影响,研究成果可以为河口极值水位和流速计算、泥沙输运、水下三角洲地貌演变等研究提供参考。 相似文献
12.
Zai-Jin You 《Ocean Engineering》1996,23(7):619-628
Current velocity profiles in the presence of non-breaking waves on a horizontal bottom are studied. Particular consideration is given to the derivations of measured current profiles from the standard logarithmic profiles near the mean water surface. The deviations are found to be due mainly to the wave-induced second-order stress which was generally neglected in the former models. The available experimental data indicate that the wave-induced second-order stress is a linear function of elevation and depends on the wave parameters, the current strength and the angle between the waves and the current. A semi-empirical model is developed and gives good agreements with experimental measurements of current profiles near the mean water surface. 相似文献
13.
The effect of wave-induced radiation stress on storm surge during Typhoon Saomai (2006) 总被引：5，自引：1，他引：4
The effects of wave-induced radiation stress on storm surge were simulated during Typhoon Saomai using a wave-current coupled model based on ROMS (Regional Ocean Modeling System) ocean model and SWAN (Simulating Waves Nearshore) wave model.The results show that radiation stress can cause both set-up and set-down in the storm surge.Wave-induced set-up near the coast can be explained by decreasing significant wave heights as the waves propagate shoreward in an approximately uniform direction;wave-induced set-down far from the coast can be explained by the waves propagating in an approximately uniform direction with increasing significant wave heights.The shoreward radiation stress is the essential reason for the wave-induced set-up along the coast.The occurrence of set-down can be also explained by the divergence of the radiation stress.The maximum wave-induced set-up occurs on the right side of the Typhoon path,whereas the maximum wave induced set-down occurs on the left side. 相似文献
14.
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
15.
Owing to lack of observational data and accurate definition,it is difficult to distinguish the Kuroshio intrusion water from the Pacific Ocean into the South China Sea(SCS).By using a passive tracer to identify the Kuroshio water based on an observation-validated three-dimensional numerical model MITgcm,the spatio-temporal variation of the Kuroshio intrusion water into the SCS has been investigated.Our result shows the Kuroshio intrusion is of distinct seasonal variation in both horizontal and vertical directions.In winter,the intruding Kuroshio water reaches the farthest,almost occupying the area from 18°N to 23°N and 114°E to 121°E,with a small branch flowing towards the Taiwan Strait.The intrusion region of the Kuroshio water decreases with depth gradually.However,in summer,the Kuroshio water is confined to the east of 118°E without any branch reaching the Taiwan Strait;meanwhile the intrusion region of the Kuroshio water increases from the surface to the depth about 205 m,then it decreases with depth.The estimated annual mean of Kuroshio Intrusion Transport(KIT) via the Luzon Strait is westward to the SCS in an amount of –3.86×106 m3/s,which is larger than the annual mean of Luzon Strait Transport(LST) of –3.15×106 m3/s.The KIT above 250 m accounts for 60%–80% of the LST throughout the entire water column.By analyzing interannual variation of the Kuroshio intrusion from the year 2003 to 2012,we find that the Kuroshio branch flowing into the Taiwan Strait is the weaker in winter of La Ni?a years than those in El Ni?o and normal years,which may be attributed to the wind stress curl off the southeast China then.Furthermore,the KIT correlates the Ni?o 3.4 index from 2003 to 2012 with a correlation coefficient of 0.41,which is lower than that of the LST with the Ni?o 3.4 index,i.e.,0.78. 相似文献
16.
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
17.
Mathematical Models for Combined Refraction-Diffraction of Waves on Non-Uniform Current and Depth 总被引：12，自引：2，他引：12
Hong Guangwen
Professor Research Institute of Coastal Ocean Engineering Hohai University Xikang Road Nanjing 《中国海洋工程》1996,(4)
Two mathematical models for combined refraction-diffraction of regular and irregular waves on non-uniform current in water of slowly varying topography are presented in this paper. Model I is derived by wave theory and variational principle separately. It has two kinds of expressions including the dissipation term. Model n is based on the energy conservation equation with energy flux through the wave crest lines in orthogonal curvilinear coordinates and the wave kinematic conservation equation. The analysis and comparison and special cases of these two models are also given. 相似文献
18.
风作用于水面产生风浪, 其中由于波流紊动产生的动量和能量的交换机制是一个很复杂的过程。风应力一般用来描述这种能量交换, 可以分为3个部分: 水面的剪切力、波生应力以及紊动应力。采用一种有效的非线性波流分离方法——NSFM(Nonlinear Stream Function Method)对波流运动的动量和能量输移进行定性描述。构造能够有效表达非线性波浪的解析流函数, 摄动求解使其满足拉普拉斯方程、动力边界条件和运动边界条件, 结合实验室风浪数据, 分离出波生速度场。通过交叉谱分析, 得到波生雷诺应力在不同风速下对风应力的贡献。结果表明: NSFM对不同工况条件下的风浪的处理具有较高的精度, 模型适应性良好; 且风速越大, 波生应力沿着水深衰减得越快, 且自由面波生应力在动量输移中的比重会逐渐减弱。 相似文献
19.
The subject of the wave–seabed–structure interaction is important for civil engineers regarding stability analysis of foundations for offshore installations. Most previous investigations have been concerned with such a problem in the vicinity of a simple structure such as a vertical wall. For more complicated structures such as a pipeline, the phenomenon of the wave–seabed–structure has not been fully understood. This paper proposes a finite-difference model in a curvilinear coordinate system to investigate the wave-induced seabed response in a porous seabed around a pipeline. Based on the present numerical model, mechanism of the wave-induced soil response is examined. Employing Mohr–Coulomb failure criterion, the wave-induced seabed instability is also estimated. The numerical results indicate the importance of the effect of pipeline on the seabed response. 相似文献