Effect of Berm Width and Elevation on Irregular Wave Run-Up

This paper discusses the effect of berm width and elevation of composite slope on irregular wave run-up. Based on the data obtained from model tests, the formula and distribution of irregular wave run-up on composite slope are derived. The changing of wind speed, width and elevation of the berm are considered comprehensively. The wave run-up with various exceedance probability can be es-timated utilizing the distribution curves of irregular wave run-up.

Impedance Analytical Method of Wave Run-up and Reflection from A Slotted-Wall Caisson Breakwater

An impedance analytical method （IAM） is developed to study the interaction of plane water wave with a slotted-wall caisson breakwater. The non-linear boundary condition at the slotted-wall is expressed in terms of flow resistance. A set of algebraic expressions are obtained for free surface elevation inside and outside chamber, and reflection coefficient. The prediction of the reflection coefficients shows that the relative widths of the chamber inducing the minimum reflection coefficient for a slotted-wall caisson breakwater are in a range of 0.10～0.20, which are smaller than that （0.15～0.25） for a perforated-wall caisson breakwater. The reflection coefficients and free surface elevation obtained by the present model are compared with that of laboratory experiments carried out by previous researchers.

Experimental Study on 2-D Focusing Wave Run-up on A Vertical Cylinder

In this paper,the focused wave groups with different parameters and their actions on a vertical cylinder are experimentally studied. The harmonic wave characteristics of the focusing waves are analyzed by the addition and subtraction of the crest and trough focusing waves. The analyzed results show that higher order harmonics can be generated because of the interaction of component waves. Nonlinearity increases with the inputted wave amplitude and the frequency width increment. Further, the wave run-up around the vertical circular cylinder is experimentally studied. It increases with the wave steepness and the relative cylinder diameter increase. However, the variations of wave run-up around the circular cylinder are different. The researches provide a reference for further numerical studies.

Wave Run-up on A Coaxial Perforated Circular Cylinder

This paper describes a plane regular wave interaction with a combined cylinder which consists of a solid inner column and a coaxial perforated outer cylinder. The outer perforated surface is a thin porous cylinder with an annular gap between it and the inner cylinder. The non-linear boundary condition at the perforated wall is a prime focus in the study; energy dissipation at the perforated wall occurs through the resistance to the fluid across the perforated wall. Explicit analytical formulae are presented to calculate the wave run-up on the outer and inner surfaces of the perforated cylinder and the surface of the inner column. The theoretical results of the wave run-up are compared with previous experimental data. Numerical results have also been obtained： when the ratio of the annular gap between the two cylinders to incident wavelength （b-a）/L≤0. 1, the wave run-up on the inner surface of the perforated cylinder and the surface of inner column can partially or completely exceed the incident wave height.

Wave Run-up on A Vertical Seawall Protected by An Offshore Submerged Barrier

Submerged barriers are constructed in coastal zones for shoreline or harbor protection or to prevent the beach erosion. In the present study, the wave run-up on a vertical seawall protected by a submerged barrier is analyzed. The physical configurations include a rigid barrier and a long channel of finite depth. For linear water waves, by matching the velocity along the barrier and along the gap, the systems of linear equations about the velocity potentials are obtained. The wave rim-up is further analyzed for various settings of barrier height and distance between the barrier and the wall, i.e. the chamber length. For nonlinear waves and random sea waves, a numerical model is extended to investigate the effect parameters of the barrier on the wave rim-up against the seawall. Not only the numerical simulations, but also the analytical results illustrate that the wave run-up on the seawall depends very much on the distance between the barrier and the vertical seawall.

Numerical Investigation of Run-ups on Cylinder in Steep Regular Wave

The run-up on offshore structures induced by the steep regular wave is a highly nonlinear flow with a free surface. This article focuses on the investigation of the steep regular wave run-up on a single vertical cylinder by solving the Navier-Stokes equations. A numerical wave tank is established based on the open-source package to simulate the wave scattering induced by a vertical cylinder. The VOF method is applied to capture the large deformation and breaking of the free surface. The numerical model is validated by experimental results. The relative wave run-ups on the front face and the back face along the centerline of a cylinder are analyzed. The changes of the relative run-ups with the wave steepness, the relative diameter and the relative depth are studied. It is found that the relative run-ups on the front face and the back face of the cylinder depend mainly on the wave steepness and the relative diameter, while the dependence on the relative depth is weak. The empirical formulae are proposed to calculate the relative run-ups in terms of the wave steepness of incident regular waves and the relative diameter of a cylinder.

Application of artificial neural network to calculation of solitary wave run-up

The prediction of solitary wave run-up has important practical significance in coastal and ocean engineering, but the calculation precision is limited in the existing models. For improving the calculation precision, a solitary wave run-up calculation model was established based on artificial neural networks in this study. A back-propagation （BP） network with one hidden layer was adopted and modified with the additional momentum method and the auto-adjusting learning factor. The model was applied to calculation of solitary wave run-up. The correlation coefficients between the neural network model results and the experimental values was 0.996 5. By comparison with the correlation coefficient of 0.963 5, between the Synolakis formula calculation results and the experimental values, it is concluded that the neural network model is an effective method for calculation and analysis of solitary wave ran-up.

Prediction on Irregular Wave Run-up and Overtopping

A series of hydraulic model tests are carried out to investigate random wave run-up and overtopping on smooth, impermeable single slope and composite slope. Based on the analysis of the influences of wave steepness, structure slope, incident wave angle, width of the berm and water depth on the berm and the wave run-up, empirical formulas for wave run-up on dike are proposed. Moreover, empirical formula on estimating the wave run-up on composite slope with multiple berms is presented for practical application of complex dike cross-section. The present study shows that the influence factors for wave overtopping are almost the same as those for wave run-up and the trend of the wave overtopping variation with main influence parameters is also similar to that for wave run-up. The trend of the wave overtopping variations can be well described by two main factors, i.e. the wave run-up and the crest freeboard of the structure. A new prediction method for wave overtopping is proposed for random waves. The proposed prediction formulas are applied to case study of over forty cases and the results show that the prediction methods are good enough for practical design purposes.

Experiments on Transformation and Run-Up of Wave Trains

This paper. details experiments undertaken in the UK Coastal Research Facility (CRF)at Hy draulies Research (HR), Wallingford, on transformation and run-up of wave trains. The purpose of these experiments is to provide verification data for numerical models of wave transformation in shoaling. surf and swash zones. This is the kind of data ih:lt flume experiments are unable to provide, and is collected in the highly controlled environment of CRF where extrinsic factors present in the field are not an issue. The experiments concerning wave trains are undertaken by use of existing wave generation software, and the run-up measurements are made with large experimental run-up gauges.

Study on the Simulation and Run-up of Ship Waves of Express Liners in the Zhujiang Delta

Ship waves are observed with wave-generating techniques by way of simulating express liners in the Zhujiang Delta.The analog test study of ship waves is conducted in a wave flume and a wave basin respectively. Thus, different wave elements and different incident angles of ship waves are decided; so are different slopes of protection, the plafform, width of plafform, and the influence over the ship wave run-up on protection from armor coat structure. The empirical relation-

Effect of Wave Groups on Wave Run-up

-The effect of wave group on wave run-up on a slope dike is mainly discussed in this paper. Two simulating methods of wave group and their applications in laboratory are introduced. Synthesizing the research results of wave run-up on a slope dike, the effect of wave group on wave run-up on a slope dike in coastal protection engineering is studied as the main point.

Analysis of the pressure at a vertical barrier due to extreme wave run-up over variable bathymetry

The pressure load at a vertical barrier caused by extreme wave run-up is analysed numerically, using the conformal mapping method to solve the two-dimensional free surface Euler equations in a pseudospectral model. Previously this problem has been examined in the case of a flat-bottomed geometry. Here,the model is extended to consider a varying bathymetry. Numerical experiments show that an increasing step-like bottom profile may enhance the extreme run-up of long waves but result in a reduced pressure load.

下陡上缓混合式海堤上不规则波爬高研究

波浪爬高是影响海堤堤顶高程的一个重要因素,直接影响工程投资。下部为陡墙、上部为斜坡、中间带平台的海堤为我国沿海常见的一种海堤断面型式,为研究此种海堤断面型式上不规则波爬高规律,通过物理模型试验观测得到不同试验条件下波浪爬高,并根据海堤下部陡墙坡度、上部斜坡坡度、平台宽度与平台高度、波浪要素对波浪爬高的影响分析,拟合了不规则波爬高计算公式。结果表明,陡墙坡度为0的海堤的波浪爬高值比0.5小;当波陡在0.03~0.05之间时,随着海堤上部坡度变缓,大部分波浪爬高逐渐减小;波浪爬高随着平台宽度的增加而减小;波浪爬高随着海堤平台位置的降低而增大;波浪爬高随着波陡的增加呈现先增大后减小的趋势;拟合公式可反映下部为陡墙、中间为平台、上部为斜坡的混合式海堤断面上波浪爬高规律。

多自由度振荡浮子装置波浪爬升特性试验与数值模拟

增加振荡浮子式波浪能发电装置的自由度可以拓宽设备的捕获频带,从而有效地提高其捕获效率,但这也意味着浮子与波浪间的作用过程更加复杂,产生的波浪爬升等非线性现象不容忽视,严重时甚至会发生越浪从而降低浮子装置的使用寿命和效率.本文开展了规则波作用下多自由度浮子迎浪侧波浪爬升特性的物理模型试验,对单自由度运动和多自由度耦合运动的浮子上的波浪爬高进行了比较,以分析在有无动力输出装置(power take-off,PTO)阻尼条件下自由度之间的相互作用效应,并使用数值模拟分析耦合运动浮子周围的流场分布.结果显示,增加自由度可以导致没有PTO阻尼的浮子上的波浪爬高显著降低,有效降低越浪风险.对于有PTO阻尼的多自由度振荡浮子,增加垂荡方向上的PTO阻尼力对波浪爬升有很大影响.三自由度耦合运动浮子能更好地利用波浪能并具有更好的安全性.

RS堆积体滑坡涌浪特征数值模拟研究

库区滑坡涌浪是滑坡产生的次生灾害,严重威胁库区工程安全及大坝稳定运行.澜沧江RM水电站RS堆积体方量巨大,且位于近坝区,开展RMRS堆积体滑坡涌浪特征研究对大坝工程安全设计和施工至关重要.本文建立RS堆积体滑坡涌浪远近场计算模型,基于光滑粒子流体动力学方法及浅水方程,研究RM工程正常蓄水位2895m情况下RS堆积体滑动产生的涌浪特征,并与经验公式法进行对比.研究表明:分析所采用的数值模拟方法在研究滑坡涌浪中具有优势,该方法可准确模拟滑坡体入水产生的非线性流固耦合过程,准确捕捉涌浪传播过程中受到复杂地形影响以及爬升过程中的地形相关性.研究结果可为评估RMRS堆积体滑坡涌浪对工程安全的影响提供参考.

一种新型护面加翼块体的消浪特性试验研究

利用物理模型试验评估了一种新型人工护面块体(加翼块体)的消浪性能,分析了波浪爬高、波浪反射系数、糙渗系数和经济效益等多项指标,并与扭王字块体进行了横向对比。研究结果表明:波浪爬高随入射波高的增大而增大,波浪在加翼块体护面上的爬高要小于扭王字块体工况,加翼块体护面的斜坡堤反射系数整体上小于扭王字块体护面的斜坡堤;利用反射波高公式计算得到的加翼块体平均糙渗系数推荐值为0.383,利用波浪爬高公式计算得到加翼块体平均糙渗系数推荐值为0.456;加翼块体护面的斜坡堤与规则安装了同等重量扭王字块体的斜坡堤相比,具有更优的消浪性能(波浪反射率平均减小了18.5%、波浪爬高平均减小3.0%)和更好的经济性(造价减小18.6%)。

One-Dimensional Horizontal Boussinesq Model Enhanced for Non-Breaking and Breaking Waves

Based on a set of fully nonlinear Boussinesq equations up to the order of O（μ^2, ε^3μ^2） （where ε is the ratio of wave amplitude to water depth and ,μ is the ratio of water depth to wave length） a numerical wave model is formulated. The model＇s linear dispersion is acceptably accurate to μ ≌ 1.0, which is confirmed by comparisons between the simulat- ed and measured time series of the regular waves propagating on a submerged bar. The moving shoreline is treated numer- ically by replacing the solid beach with a permeable beach. Run-up of nonbreaking waves is verified against the analytical solution for nonlinear shallow water waves. The inclusion of wave breaking is fulfilled by introducing an eddy term in the momentum equation to serve as the breaking wave force term to dissipate wave energy in the surf zone. The model is applied to cross-shore motions of regular waves including various types of breaking on plane sloping beaches. Comparisons of the model test results comprising spatial distribution of wave height and mean water level with experimental data are presented.

Operational Wave Now- and Forecast in the German Bight as a Basis for the Assessment of Wave-Induced Hydrodynamic Loads on Coastal Dikes

The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.

Wave Action on Structures of Combined Cylinders

The scattering of water wave by an array of combined cylinders with solid interior columns and partially perforated exterior columns at the upper section of an outer wall is solved with a linear model for the pressure difference between the two sides of a porous wall and the fluid velocity inside it. A semi-analytic linear solution is established by the eigenfunction expansion method for wave diffraction from the array of combined cylinders. Both numerical experiment and physical experiment are carried out to verity the theory. Also presented are some numerical examples to show the situation of wave force on the cylinders influenced by the effeet factor of porosity G, relative wave number ka and the ratio of water depth inside and outside the cylinders.

港珠澳大桥人工岛波浪爬高试验研究

港珠澳大桥人工岛位于珠江外海,工程区波浪较大,在台风季节人工岛会发生显著的波浪爬高,对隧道安全造成影响。通过人工岛护岸断面波浪物理模型试验,研究了人工岛护岸断面各结构参数和波浪破波参数等对波浪爬高的影响规律,并提出了人工岛复式斜坡堤护岸波浪爬高的计算方法。研究表明,对于该人工岛护岸断面结构型式以及试验水位和波浪条件,复坡平台宽度对波浪爬高影响较大,而平台高程对波浪爬高影响不明显;相对爬高值随破波参数的变化主要位于缓变段。经比较,文章提出的波浪爬高计算方法的计算结果与物理模型试验结果数据吻合良好,可为港珠澳大桥人工岛波浪爬高和越浪量预警提供技术支撑。