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1.
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 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 discharge 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 discharge 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. 相似文献
2.
半潜平台的波浪爬升与气隙响应是设计过程中的重要考量因素。为探究随机波浪场中畸形波对半潜平台波浪爬升及气隙响应的影响,将含畸形波的随机波浪试验与一般随机波浪试验结果进行了对比研究分析。对模型试验测得的运动以及监测点处的波浪爬升及气隙进行频谱分析以及极值统计分析。研究发现,纵荡和纵摇的极大值主要受畸形波的影响而显著增大,纵荡、垂荡以及纵摇响应谱几乎不受单个畸形波影响;波浪爬升与气隙的极大值受到畸形波的影响而增大,同时,畸形波对气隙响应谱造成极大影响,增强了波浪爬升与气隙响应的非线性性。 相似文献
3.
《Coastal Engineering》1999,36(3):219-242
This paper presents numerical simulations and analytical predictions of key aspects of swash oscillations on a steep beach. Simulations of the shoreline displacement based on bore run-up theory are found to give excellent agreement with recent experimental data for regular waves, wave groups and random waves. The theory is used to derive parameters that predict the onset of swash saturation and the spectral characteristics of the saturated shoreline motion. These parameters are again in good agreement with the measured laboratory data and are also consistent with previous experimental data. Simulation of irregular wave run-up using a series of overlapping monochromatic swash events is found to reproduce typical features of swash oscillations and can accurately describe both the low and high frequency spectral characteristics of the swash zone. In particular, the low frequency components of the run-up can be modelled directly using a sequence of incident short wave bores, with no direct long wave input to the numerical simulations. This suggests that wave groupiness must be accounted for when modelling shoreline oscillations. 相似文献
4.
D. L. Kriebel 《Ocean Engineering》1992,19(1)
Theoretical results for second-order wave run-up around a large diameter vertical circular cylinder are compared to results of 22 laboratory experiments conducted in regular nonlinear waves. In general, the second-order theory explains a significant portion of the nonlinear wave run-up distribution measured at all angles around the cylinder. At the front of the cylinder, for example, measured maximum run-up exceeds linear theory by 44% on average but exceeds the nonlinear theory by only 11% on average. In some cases, both measured run-up and the second-order theory exceed the linear prediction by more than 50%. Similar results are found at the rear of the cylinder where the second-order theory predicts a large increase in wave amplitude for cases where the linear diffraction theory predicts little or no increase. Overall, the nonlinear diffraction theory is found to be valid for the same relative depth and wave steepness conditions applicable to Stokes second-order plane-wave theory. In the last section of the paper, design curves are presented for estimating the maximum second-order wave run-up for a wide range of conditions in terms of the relative depth, relative cylinder size, and wave steepness. 相似文献
5.
I. I. Didenkulova A. A. Kurkin E. N. Pelinovsky 《Izvestiya Atmospheric and Oceanic Physics》2007,43(3):384-390
The problem of sea-wave run-up on a beach is discussed within the framework of exact solutions of a nonlinear theory of shallow water. Previously, the run-up of solitary waves with different forms (Gaussian and Lorentzian pulses, a soliton, special-form pulses) has already been considered in the literature within the framework of the same theory. Depending on the form of the incident wave, different formulas were obtained for the height of wave run-up on a beach. A new point of this study is the proof of the universality of the formula for the maximum height of run-up of a solitary wave on a beach for the corresponding physical choice of the determining parameters of the incident wave, so that the effect of difference in form is eliminated. As a result, an analytical formula suitable for applications, in particular, in problems related to tsunamis, has been proposed for the height of run-up of a solitary wave on a beach. 相似文献
6.
Numerical investigation on the dynamics of a vertical wall defenced by an offshore breakwater 总被引：1，自引：0，他引：1
The numerical and experimental investigations on the performance of an offshore-submerged breakwater in reducing the wave forces and wave run-up on vertical wall are presented. A two-dimensional finite-element model is employed to study the hydrodynamic performance of the submerged breakwater under the action of regular and random waves. The numerical prediction has been supported with experimental measurements. The wave forces and wave run-up on the vertical wall were measured for different breakwater configurations. The applicability of linear theoretical model in the prediction of wave forces on the wall by a submerged breakwater has been discussed. 相似文献
7.
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 run-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 run-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. 相似文献
8.
波浪的方向分布对波浪的传播及其与工程结构物的作用都具有明显影响，目前现有的研究大多是基于单向波浪进行的。为了研究方向分布对群墩结构上的爬高影响，基于规则波浪与群墩作用的理论解，结合多向不规则波浪的造波方法，建立了多向不规则波浪与群墩作用的计算模型，同时进行了物理模型试验对模型的有效性进行了验证。系统地对群墩周围及表面上的波浪爬高进行了计算分析，结果表明，方向分布对波浪爬高具有较大的影响，且不同位置处的影响并不相同，在实际的工程设计中如果按照单向波浪计算，可能低估或者高估群墩周围的爬高。 相似文献
9.
The boundary integral equation method (BIEM) is developed as a tool for studying two-dimensional, nonlinear water wave problems, including the phenomena of wave generation, propagation and run-up. The wave motions are described by a potential flow theory. Nonlinear free-surface boundary conditions are incorporated in the numerical formulation. Examples are given for either a solitary wave or two successive solitary waves. Special treatment is developed to trace the run-up and run-down along a shoreline. The accuracy of the present scheme is verified by comparing numerical results with experimental data of maximum run-up. 相似文献
10.
Wave run-up on foundations is a very important factor in the design of entrance platforms for offshore wind turbines. When the Horns Reef 1 wind turbine park in Denmark was designed the vertical wave run-up phenomenon was not well known in the industry, hence not sufficiently considered in the design of Horns Reef 1. As a consequence damage was observed on the platforms. This has been the situation for several sites and design tools for platform loads are lacking. As a consequence a physical model test study was initiated at Aalborg University to clarify wave run-up on cylindrical piles for different values of diameter to water depth ratios (D/h) and different wave heights to water depth ratios (H/h) for both regular and irregular waves. A calculation model is calibrated based on stream function theory for crest kinematics and velocity head stagnation theory. Due to increased velocities close to the pile an empirical factor is included on the velocity head. The evaluation of the calculation model shows that an accurate design rule can be established even in breaking wave conditions. However, calibration of a load model showed that it was necessary to increase the run-up factor on the velocity head by 40% to take into account the underestimation of run-up for breaking or nearly breaking waves given that they produce thin run-up wedges and air entrainment, two factors not coped with by the measurement system. 相似文献
11.
I. I. Didenkulova A. V. Sergeeva E. N. Pelinovsky S. N. Gurbatov 《Izvestiya Atmospheric and Oceanic Physics》2010,46(4):530-532
A run-up of irregular long sea waves on a beach with a constant slope is studied within the framework of the nonlinear shallow-water
theory. This problem was solved earlier for deterministic waves, both periodic and pulse ones, using the approach based on
the Legendre transform. Within this approach, it is possible to get an exact solution for the displacement of a moving shoreline
in the case of irregular-wave run-up as well. It is used to determine statistical moments of run-up characteristics. It is
shown that nonlinearity in a run-up wave does not affect the velocity moments of the shoreline motion but influences the moments
of mobile shoreline displacement. In particular, the randomness of a wave field yields an increase in the average water level
on the shore and decrease in standard deviation. The asymmetry calculated through the third moment is positive and increases
with the amplitude growth. The kurtosis calculated through the fourth moment turns out to be positive at small amplitudes
and negative at large ones. All this points to the advantage of the wave run-up on the shore as compared to a backwash at
least for small-amplitude waves, even if an incident wave is a Gaussian stationary process with a zero mean. The probability
of wave breaking during run-up and the applicability limits for the derived equations are discussed. 相似文献
12.
In this paper, first we introduce the wave run-up scale which describes the degree of wave run-up based on observed sea conditions near and on a coastal structure. Then, we introduce a simple method which can be used for daily forecast of wave run-up on a coastal structure. The method derives a multiple linear regression equation between wave run-up scale and offshore wind and wave parameters using long-term photographical observation of wave run-up and offshore wave forecasting model results. The derived regression equation then can be used for forecasting the run-up scale using the offshore wave forecasting model results. To test the implementation of the method, wave run-up scales were observed at four breakwaters in the East Coast of Korea for 9 consecutive months in 2008. The data for the first 6 months were used to derive multiple linear regression equations, which were then validated using the run-up scale data for the remaining 3 months and the corresponding offshore wave forecasting model results. A comparison with an engineering formula for wave run-up is also made. It is found that this method can be used for daily forecast and warning of wave run-up on a coastal structure with reasonable accuracy. 相似文献
13.
近岸植被对波浪爬坡具有一定的衰减作用。在自然界中，由于植被的死亡、再生或人为破坏等原因，近岸植被通常呈片状分布，且其内部分布也是不均匀的。本文以完全非线性Boussinesq方程为基础，引入植被作用项，建立了模拟近岸植被区波浪传播的数值模型，验证了模型可靠性，进而采用该模型模拟分析了片状分布植被对孤立波爬高的影响。数值模拟结果表明，片状分布植被能有效减小孤立波爬高；对于均匀分布的片状植被，高密度片状植被对孤立波爬高的消减效果优于低密度片状植被；对于相同密度、不同分布形式的片状植被，均匀分布的片状植被对孤立波的消减效果优于不均匀分布的片状植被；对于不均匀分布的片状植被，前密后疏的片状植被对孤立波的消减效果优于前疏后密的片状植被。 相似文献
14.
During the last decade, several offshore wind-farms were built and offshore wind energy promises to be a suitable alternative to provide green energy. However, there are still some engineering challenges in placing the foundations of offshore wind turbines. For example, wave run-up and wave impacts cause unexpected damage to boat landing facilities and platforms. To assess the forces due to wave run-up, the distribution of run-up around the pile and the maximum run-up height need to be known. This article describes a physical model study of the run-up heights and run-up distribution on two shapes of foundations for offshore wind turbines, including both regular and irregular waves. The influence of wave steepness, wave height and water depth on run-up is investigated. The measured run-up values are compared with applicable theories and previous experimental studies predicting run-up on a circular pile. 相似文献
15.
The run-up and back-wash processes of single and double solitary waves on a slope were studied experimentally. Experiments were conducted in three different wave flumes with four different slopes. For single solitary wave, new experimental data were acquired and, based on the theoretical breaking criterion, a new surf parameter specifically for breaking solitary waves was proposed. An equation to estimate maximum fractional run-up height on a given slope was also proposed. For double solitary waves, new experiments were performed by using two successive solitary waves with equal wave heights; these waves were separated by various durations. The run-up heights of the second wave were found to vary with respect to the separation time. Particle image velocimetry measurements revealed that the intensity of the back-wash flow generated by the first wave strongly affected the run-up height of the second wave. Showing trends similar to that of the second wave run-up heights, both the back-wash breaking process of the first wave and the reflected waves were strongly affected by the wave–wave interaction. Empirical run-up formula for the second solitary wave was also introduced. 相似文献
16.
The dynamic pressures due to random waves of predefined spectral characteristics exerted on a semicircular breakwater model at five different elevations along the depth are measured. In addition, the wave run-up on the model and its reflection characteristics are measured. The results on the variation of the frequency pressure spectra along the depth and the run-up spectra are reported in this paper. The average spectral characteristics as well as statistical properties of the above two parameters are presented. The average reflection coefficient is reported as a function of the wave steepness, described as the ratio of the significant wave height to the square of the peak period. 相似文献
17.
Benchmark computations of wave run-up on single cylinder and four cylinders by naoe-FOAM-SJTU solver
The benchmark simulations of wave run-up on a fixed single truncated circular cylinder and four circular cylinders are presented in this paper. Our in-house CFD solver naoe-FOAM-SJTU is adopted which is an unsteady two-phase CFD code based on the open source package OpenFOAM. The Navier-Stokes equations are employed as the governing equations, and the volume of fluid (VOF) method is applied for capturing the free surface. Monochromatic incident waves with the specified wave period and wave height are simulated and wave run-up heights around the cylinder are computed and recorded with numerical virtual wave probes. The relationship between the wave run-up heights and the incident wave parameters are analyzed. The numerical results indicate that the presented naoe-FOAM-SJTU solver can provide accurate predictions for the wave run-up on one fixed cylinder and four cylinders, which has been proved by the comparison of simulated results with experimental data. 相似文献
18.
Ching-Her Hwang 《Ocean Engineering》1988,15(3)
Experimental studies of wave transmission by overtopping for a smooth impermeable breakwater with 1:1.5 slope under both regular and random waves were conducted. A resulting relationship between the transmission coefficient (determined by wave height and wave period) and a breakwater height above mean water level normalized with the height of wave run-up measured directly by capacity wave meter is reported. Meanwhile, their discrepancies in both regular and random waves are also discussed in this study. The authors find also that the transmitted significant wave period by overtopping of random waves may be much longer than those of the incoming wave. This characteristic is especially prominent and probably creates the oscillation phenomenon in the wave basin at the back of breakwater when the breakwater height (above mean water level) to water depth ratio is greater than 0.23 and the incoming wave period is longer than 8 sec. 相似文献
19.
为了研究波浪非线性对爬高的影响,解决防波堤等工程设计的实际问题,通过对数学模型试验、物理模型试验、规范公式得到的防波堤波浪爬高对比分析,分析了非线性主要影响参数厄塞尔数、相对水深和波陡对波浪爬高的影响规律,指出规范公式计算时存在的缺陷,并对其计算公式、适用范围进行修正、拟合,得到了强非线性规则波浪爬高的计算方法,可适用于斜坡堤断面的波浪爬高计算,与物理模型试验和数学模型试验结果对比表明,新的波浪爬高计算公式具有较好的计算精度,研究结果可为防波堤等实际工程设计提供重要参考。 相似文献
20.
I. I. Didenkulova E. N. Pelinovsky O. I. Didenkulov 《Izvestiya Atmospheric and Oceanic Physics》2014,50(5):532-538
We study the run-up of long solitary waves of different polarities on a beach in the case of composite bottom topography: a plane sloping beach transforms into a region of constant depth. We confirm that nonlinear wave deformation of positive polarity (wave crest) resulting in an increase in the wave steepness leads to a significant increase in the run-up height. It is shown that nonlinear effects are most strongly pronounced for the run-up of a wave with negative polarity (wave trough). In the latter case, the run-up height of such waves increases with their steepness and can exceed the amplitude of the incident wave. 相似文献