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1.
海啸波经极缓的大陆架传播至近岸浅水区时可激发由多个孤立波组成的波列。为了研究多个孤立波在斜坡上爬高和相互作用规律,该文选择坡度为1/20的斜坡模型在波浪水槽进行了等波幅三孤立波爬高的物理模型实验。采用大冲程推板式造波机和改进的Goring造波方法,有效地实现了不同波峰间距和不同相对波幅时等波幅三孤立波的造波。采用高速摄像机记录每个孤立波的爬高过程,得到每个孤立波的爬高值;定性分析了爬高过程中孤立波破碎及其相互作用对爬高的影响规律。实验结果表明:第二个孤立波和第三个孤立波受先导波回落水流的影响,破碎位置向离岸方向移动;首波的爬高放大系数基本不受后续来波的影响,其爬高放大系数与同等工况下单孤立波的测量值一致;第二个孤立波和第三个孤立波的爬高放大系数与相邻的波峰间距有关,当波峰间距增大时,爬高放大系数先减少后增加;当波峰间距增至某临界值后时,第三个孤立波的爬高放大系数将大于第二个波的爬高放大系数。最后,依据本次实验结果,提出了等波幅三孤立波在缓坡上爬高的经验公式。  相似文献   

2.
海啸波在近海传播过程中有可能会演化成若干个孤立波组成的波列.为了研究孤立波波列对海岸结构物的作用机理,本文在波浪水槽中进行了双孤立波的直墙爬高实验.通过控制推板式造波机的运动,有效地实现了不同波峰间距双孤立波的造波方法.在复演并验证单孤立波直墙爬高的基础上,完成了不同相对波高、相对波峰间距的双孤立波爬高系列实验,给出了双孤立波平底传播及直墙爬高过程的波面时间序列及爬高过程水线运动时间序列.实验结果表明:对两个等波高的双孤立波而言,当相对波峰间距降到某临界值时,跟随在后孤立波的爬高放大系数将小于先导孤立波的爬高放大系数;当先导孤立波的波高大于跟随孤立波的波高,先导孤立波将更加显著地抑制对跟随孤立波的爬高过程,使得后者的最高爬放大系数显著减小;若在直墙爬高前两个波已明显重叠,即呈双峰瞬态波形,爬高放大系数不会大于具有相同波高的单孤立波的爬高放大系数.  相似文献   

3.
该文通过物理模型实验和数值模拟研究了孤立波与斜坡上非淹没刚性植被的相互作用。物理模型实验在波浪水槽中进行,运用CCD高速相机测量了斜坡上波浪的爬高,分析了入射波波高和植被密度对爬高的影响,结果表明爬高与入射波高的比值近似为常数,其值取决于植被的密度。采用Boussinesq方程成功地模拟了波浪在斜坡上的传播变形及爬高过程:植被的阻水作用通过添加拖曳力项来实现,底床摩擦阻力系数通过模拟孤立波在无植被影响斜坡上的爬高确定,根据实验数据校核数值模型得到不同入射波高下植被的拖曳力系数。研究发现孤立波作用下斜坡上植被的平均拖曳力系数与平底床恒定流的情况并无明显差异。  相似文献   

4.
孤立波浅化过程的SPH数值模拟   总被引:1,自引:0,他引:1  
本文应用光滑粒子流体动力学(SPH)方法建立了二维数值波浪水槽,研究了孤立波沿斜坡的传播、变形和破碎过程。通过数值计算分析了波浪沿斜坡传播过程中自由表面的变化特征,给出了斜坡上不同位置处波面变化的历时曲线,并应用文献记录的试验结果对数模结果进行了验证。得到了波高的沿程变化趋势、破波点的位置和破碎波高以及不同破碎形态下波浪自由表面的变化特征,显示了SPH方法在处理较复杂自由表面流动问题方面的优越性。  相似文献   

5.
为了研究海啸等浅水大波对海堤等海岸结构物的作用,采用孤立波作为输入波形,在波浪水槽中进行了孤立波在斜坡堤上越浪过程的系列实验。通过物理模型实验,获得了孤立波作用下斜坡堤越浪量的测量结果,并基于PIV方法测量得到的海堤越浪流速度场计算了越浪量。以堤顶相对超高和来波相对波高为无量纲参数,基于越浪量实验数据建立了斜坡堤上孤立波越浪量的经验预报公式。孤立波堤顶越浪流的PIV测量结果表明,在实验工况条件下越堤流流场可近似为几乎平行的流动;基于PIV测量结果得到孤立波越浪量与越浪量的直接测量结果一致性较好。对简单斜坡堤而言,无量纲的孤立波越浪量随来波相对波高的增大而增加,随着堤顶相对超高的减小呈指数增大。  相似文献   

6.
基于CFD技术建立的数值波浪水槽试验,使用了波浪理论构建的数值水槽模型,在一定程度上能够代替物理实验的波浪水槽.数值波浪水槽构建难点在于实际波浪由于受到建筑物、地形等影响,往往会发生破碎、涡旋等现象,造波消波方法的选择也会对数值水槽建立和计算的准确性产生不同程度的影响.本文采用FLOW-3D软件,利用VOF方法,建立波浪数值水槽,将实验结果与Vincent and Briggs的椭圆浅滩实验结果对比,二者较为一致,说明波浪数值水槽结果合理有效.  相似文献   

7.
植物蜂巢护岸兼顾绿化及水土保持加固等功能,是一种新型的生态护岸形式。该文通过大比尺物理模型实验,考虑波高、水深和滩地形态的影响,对规则波和孤立波在蜂巢生态护岸上的爬高特性进行了研究。结果表明,参考抛石护岸,植物蜂巢护岸可以降低规则波爬高,但坡面材料对孤立波爬高的影响不明显。不发生越浪时,规则波经过缓坡滩地后,在护岸上的爬高低于水平滩地条件。而且,蜂巢生态护岸与滩地种树结合可以进一步减小孤立波爬高。该文还通过对实验数据进行汇总,对不同滩地形态及不同护岸坡面情况下波浪爬高特性进行了分析,得到了规则波和孤立波的爬高特性关系式,可为生态堤防堤顶高程设计和相应的数值计算提供相关依据。  相似文献   

8.
该文基于Open FOAM开源程序包建立波浪数值水槽,对孤立波在斜坡上的水动力特性进行模拟。运用实验数据验证了数学模型的精度和可靠性,进一步研究岸滩剖面变化的成因,并分析冲刷区不同位置泥沙颗粒所受水流冲量的变化规律,发现地形冲刷变化与水流的冲量作用为正相关,回落过程中水流冲量大于上爬过程,因而冲刷主要发生在回落过程。探讨淤积区泥沙颗粒的受力特征,发现由于水跃过程中漩涡作用,中层水流的泥沙颗粒出现向上受力,泥沙颗粒由底部回落水流向上部水流转移,水跃后期泥沙颗粒受力方向为向岸向下,岸滩最大淤积位置出现在水跃中水体涡量最大时的临近向岸区域。  相似文献   

9.
黏性波浪场与半潜平台相互作用的数值模拟   总被引:1,自引:0,他引:1  
以N-S方程为控制方程,采用动量源方法,结合追踪自由面的VOF方法,基于FLUENT求解器,建立了同时具有造波和消波功能的数值波浪水槽.利用该数值水槽对黏性波浪场与半潜平台的相互作用问题进行了数值模拟,获得了黏性波浪场作用下半潜平台水动力载荷及其立柱表面波浪爬高的时历特性.研究表明,利用所建立的数值波浪水槽来研究黏性波浪场与深海平台非线性相互作用是一条有效的途径.  相似文献   

10.
带异形块体海堤越浪的数值模拟   总被引:4,自引:3,他引:1  
该文在FLUENT软件平台上,发展了数值消波-造波技术,通过在动量方程里添加多孔介质源项,建立了带有多孔介质模型的二维数值波浪水槽。应用该数值波浪水槽,数值模拟了在斜坡堤坡面上铺设异形块体情况下的越浪过程,给出了越浪量。为了率定异形块体的等效惯性阻力系数,进行了典型工况的物理模型实验,给出了在斜坡堤坡面上不同位置处铺设一层异形块体情况下多孔介质模型的等效阻力系数。  相似文献   

11.
An experimental study on runup of two solitary waves on plane beaches   总被引:2,自引:0,他引:2  
Experiments of the runup of two solitary waves on a plane beach are carried out in a wave flume. The two solitary waves with the same amplitude and the crest separating distances are generated by using an improved wave generation method. It is found that, with regard to the two solitary waves with same wave amplitude, the runup amplification of the second wave is less than that of the first wave if the relative crest separating distance is reduced to a certain threshold value. The rundown of the first solitary wave depresses the maximum runup of the second wave. If the leading solitary wave is of relatively smaller amplitude for the two solitary waves, the runup amplification is affected by the overtaking process of two solitary waves. It turns out that the runup amplification of the second wave is larger than that of the first wave if the similarity factor is approximately larger than 15, which means the larger wave overtakes the smaller one before the waves runup on a beach.  相似文献   

12.
The evolution and run-up of double solitary waves on a plane beach were studied numerically using the nonlinear shallow water equations(NSWEs) and the Godunov scheme. The numerical model was validated through comparing the present numerical results with analytical solutions and laboratory measurements available for propagation and run-up of single solitary wave. Two successive solitary waves with equal wave heights and variable separation distance of two crests were used as the incoming wave on the open boundary at the toe of a slope beach. The run-ups of the first wave and the second wave with different separation distances were investigated. It is found that the run-up of the first wave does not change with the separation distance and the run-up of the second wave is affected slightly by the separation distance when the separation distance is gradually shortening. The ratio of the maximum run-up of the second wave to one of the first wave is related to the separation distance as well as wave height and slope. The run-ups of double solitary waves were compared with the linearly superposed results of two individual solitary-wave run-ups. The comparison reveals that linear superposition gives reasonable prediction when the separation distance is large, but it may overestimate the actual run-up when two waves are close.  相似文献   

13.
In this article,the use of a high-order Boussinesq-type model and sets of laboratory experiments in a large scale flume of breaking solitary waves climbing up slopes with two inclinations are presented to study the shoreline behavior of breaking and non-breaking solitary waves on plane slopes.The scale effect on run-up height is briefly discussed.The model simulation capability is well validated against the available laboratory data and present experiments.Then,serial numerical tests are conducted to study the shoreline motion correlated with the effects of beach slope and wave nonlinearity for breaking and non-breaking waves.The empirical formula proposed by Hsiao et al.for predicting the maximum run-up height of a breaking solitary wave on plane slopes with a wide range of slope inclinations is confirmed to be cautious.Furthermore,solitary waves impacting and overtopping an impermeable sloping seawall at various water depths are investigated.Laboratory data of run-up height,shoreline motion,free surface elevation and overtopping discharge are presented.Comparisons of run-up,run-down,shoreline trajectory and wave overtopping discharge are made.A fairly good agreement is seen between numerical results and experimental data.It elucidates that the present depth-integrated model can be used as an efficient tool for predicting a wide spectrum of coastal problems.  相似文献   

14.
为探究海岸刚性植被对海啸波的削弱效应,通过物理模型试验和数值模拟研究了孤立波与不同坡度岸滩上非淹没刚性植被的相互作用问题。物理模型试验在波浪槽中进行,测试了不同的入射波波高、植被密度和岸滩坡度对孤立波爬高的影响,并运用物理模型试验数据校核改进后的Boussinesq方程,得到植被的拖曳力系数。结果表明:拖曳力系数随植被密度的增大而增大,随坡度增大而减小;植被后的无量纲透射波高和无量纲岸滩爬高随着无量纲的入射波高的增大而减小,随着植被密度的增大而减小;当岸滩坡度增大时,无量纲透射波高增大而无量纲爬高并无显著差异。最后根据回归分析得出了岸滩爬高与相对入射波高、植被密度和岸滩坡度的幂函数型经验关系式。  相似文献   

15.
倾斜底坡上波浪的传播与破碎   总被引:7,自引:1,他引:6  
本文根据TUMMAC方法探讨了孤立波、微幅波和二阶Stokes波在1/30底坡上的传播与破碎,并采用示踪法测得了相同底坡上濒临破碎波的速度场。与前人的实验结果相比较表明,计算所得的波浪外形变化是一致的,依据运动学标准所得的各项破碎指标也大致相同;与岩垣及本文实验结果比较表明,速度的分布趋势也是一致的。  相似文献   

16.
In this paper the propagation and breaking of the solitary wave,the sinusoidalwave and the second Stokes wave on a slope of 1/30 are discussed based upon the TUMMACmethod,and the velocity fields of breaking waves on the slope are obtained by using the tracingmethod.The.numerical results for wave deformation are in good agreement with experimentaldata,and the breaker indexes depending on the kinetic criterion agree approximately with previ-ous results.Furthermore,compared with the experimental results measured by Iwagaki and bythe authors,the tendency of velocity distribution of breaking waves computed by this numericalmethod is also satisfactory.  相似文献   

17.
The runup of breaking and non-breaking solitary waves on a plane beach has been simulated using the shallow-water equations and a Lagrangian blocks on Eulerian mesh (LBEM) method. The results obtained for the entire range of wave steepness are compared with the experimental data, the nonlinear theory, and the finite-difference method. The LBEM simulation agrees with the nonlinear theory when the amplitude of the wave is small. On the whole, it produces a better result in agreement with the experimental data when friction is included in the simulation. The simulation also produced better result than the finite-difference simulation.  相似文献   

18.
改进的非线性波传播数值模型的验证和应用   总被引:1,自引:1,他引:0  
基于吸收入射边界上反射波的方法,并通过将统一边界条件表达式推广到适应不规则波的情况,改进了非线性波传播的数值模型.将利用模型的线性版本(略去非线性项)所计算得到的台阶地形上波浪的反射和透射系数与相应的解析解进行了定量比较.在斜坡地形上数值模拟了不规则波的传播,并将数值结果和物理模型实验值进行了比较.在下游边界分别为开边界和全反射边界的等水深的水槽内数值模拟了不规则波的传播变形,讨论了非线性作用的影响.在侧边界和下游边界均为全反射的固壁边界、二维的等水深水域内,数值模拟了波浪斜向入射时所产生的波浪变形.计算结果表明,对上述各种算例,改进后的非线性波传播数值模型均能进行有效地数值模拟.  相似文献   

19.
该文通过水池物理模型实验,研究了在1:15的斜坡条件下斜向和多向波浪中破碎的特点。根据波浪类型和岸坡条件将破碎指标分为四类,总结了每一类破碎指标公式的通用形式和系数。对实验中正向和斜向规则波、正向和斜向不规则波、正向和多向不规则波的破碎指标进行了比较和分析。研究结果表明:同等条件下,斜向波的破碎指标较正向波偏大,基于不规则波有效波高的破碎指标小于规则波的,而多向波在波高较大时的破碎波高与正向不规则波相比偏小。  相似文献   

20.
NUMERICAL MODELING OF WAVE EVOLUTION AND RUNUP IN SHALLOW WATER   总被引:2,自引:1,他引:1  
Based on the Navier-Stokes (N-S) equations for viscous, incompressible fluid and the VOF method, 2-D and 3-D Numerical Wave Tanks (NWT) for nonlinear shallow water waves are built. The dynamic mesh technique is applied, which can save computational resources dramatically for the simulation of solitary wave propagating at a constant depth. Higher order approximation for cnoidal wave is employed to generate high quality waves. Shoaling and breaking of solitary waves over different slopes are simulated and analyzed systematically. Wave runup on structures is also investigated. The results agree very well with experimental data or analytical solutions.  相似文献   

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