共查询到19条相似文献,搜索用时 156 毫秒
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对被重新修正后的Goat在墙波压力计算方法进行了分析,主要是对其无因次波浪力随基床肩宽和相对波高的变化进行分析,结果发现,Goat法计算的无因次波浪力随基床肩宽的变化,有一最不利肩宽,此不利肩宽与相对波高无关;在同一水深条件下,Goat法计算的无因次波浪力随相对波高的增大而增大。此两点与试验数据不符。 相似文献
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实验室一般采用波浪聚焦方法生成深水破碎波,通过各组分波浪的波幅叠加生成一个波高显著增大的大波,使其波陡超过极限波陡发生破碎。利用该方法生成深水破碎波浪的破碎次数通常并不唯一,导致波浪破碎后的流场特征不明显;造波参数不易于选取导致研究工况的设置难度大,直接影响深水破碎精细化实验的效果和效率。本文采用聚焦波理论计算波面,并利用上跨零点法定义的波高和波长计算理论波陡,结合物理模型实验统计波浪沿程破碎次数与剧烈程度,研究以JONSWAP谱为造波输入谱型时,聚焦波幅、谱峰频率、频宽等造波输入参数对于波浪破碎情况的影响,从而建立深水波浪破碎次数与造波输入参数之间的近似定量关系,为实验造波参数的选取提供参考,提高实验效率。 相似文献
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波浪在珊瑚礁地形上破碎特性试验研究 总被引:2,自引:0,他引:2
对波浪在珊瑚礁地形上的传播特性进行了物理试验研究,将珊瑚礁地形简化为坡度为1∶5的陡坡(向海坡)加较长水平礁坪段的地形,对规则波和不规则波在该地形条件下的波浪破碎及波高沿程衰减进行了研究。结果表明,波高较小时,波浪破碎发生在礁坪上,但随着入射波高的增大,破碎位置逐渐向来浪方向移动,直至在向海坡段破碎。对于在礁坪上破碎的波浪,相对水深db/L0一定的条件下,破碎波高与入射波陡H0/L0相关,且变化趋势受相对水深db/L0的影响。同时给出了该地形条件下波浪破碎指标以及礁坪段破碎后沿程波高的计算公式。 相似文献
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引入极限波高是随机变量的概念,将近岸破碎波的波高概率分布用形式不同的未破碎波高的概率密度和已破碎波高的概率密度的相加来表示,提出了一种新的破碎波高概率分布形式。认为破碎带内的波高总体上服从瑞利分布,其中已破碎波高的概率密度按总波高的概率密度等比例分布于整个波高范围,破碎概率和当地均方根波高与极限特征波高之比有关。实验表明,本文提出的近岸破碎波高概率分布较好地体现了近岸波浪的破碎特征。 相似文献
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对三维波浪在岛礁地形上的传播特性进行了物理模型试验研究。为了探究三维波浪在岛礁地形上传播的破碎指标,将岛礁地形简化为1∶5的向海坡与水平礁坪相连的物理模型。对于不同波况下的规则波、不规则波、多向波在该地形上的破碎特性进行了研究。结果表明,在该地形条件下,较大入射波高的波浪均在礁坪上发生破碎,并且随着入射波高的增大,破碎位置向来浪方向移动,破碎指标与入射波陡H_0/L_0相关,斜向波浪传播受入射角度的影响。同时,文中也给出了在该地形下波浪的破碎指标,并将三维结果与二维结果进行了对比。 相似文献
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Wang Liang
Du Heng Lecturer Hohai University Nanjing Engineer Jiangsu Communication Planning Design Institute Nanjing 《中国海洋工程》1993,(1)
- Engineers in coastal engineering have been paying much attention to the research subject on wave breaking. In this paper, previous research results on the calculating methods of wave breaking depth and height are enumerated, the laws of wave transformation before and after wave breaking are investigated, an adequate supposition is made, and the effect of beach slope, bed friction and breaking turbulence on wave breaking is considered. By applying the theory of wave energy dissipation rate and combining with proper formulas of solitary waves, a new calculating formula of wave breaking depth and height on the movable bed is derived and examined with the data from experimental pools of different sizes, and it is proved to be of practicability. 相似文献
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Li Yucheng 《海洋学报(英文版)》1996,15(2):261-272
Thewavetransformationandbreakingphenomenainshallowwater¥LiYucheng(1.DalianUniversityofTechnology,Dalian116023,China)Abstract:... 相似文献
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Solitary wave evolution over a shelf including porous damping is investigated using Volume-Averaged Reynolds Averaged Navier–Stokes equations. Porous media induced damping is determined based on empirical formulations for relevant parameters, and numerical results are compared with experimental information available in the literature. The aim of this work is to investigate the effect of wave damping on soliton disintegration and evolution along the step for both breaking and non-breaking solitary waves. The influence of several parameters such as geometrical configuration (step height and still water level), porous media properties (porosity and nominal diameter) or solitary wave characteristics (wave height) is analyzed. Numerical simulations show the porous bed induced wave damping is able to modify wave evolution along the step. Step height is observed as a relevant parameter to influence wave evolution. Depth ratio upstream and downstream of the edge appears to be the more relevant parameter in the transmission and reflection coefficients than porosity or the ratio of wave height–water depth. Porous step also modifies the fission and the solitary wave disintegration process although the number of solitons is observed to be the same in both porous and impermeable steps. In the absence of breaking, porous bed triggers a faster fission of the incident wave into a second and a third soliton, and the leading and the second soliton reduces their amplitude while propagating. This decrement is observed to increase with porosity. Moreover, the second soliton is released before on an impermeable step. Breaking process is observed to dominate over the wave dissipation at the porous bottom. Fission is first produced on a porous bed revealing a clear influence of the bottom characteristics on the soliton generation. The amplitude of the second and third solitons is very similar in both impermeable and porous steps but they evolved differently due to the effect of bed damping. 相似文献
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Studies of the breaking criteria for solitary waves on a slope are presented in this paper. The boundary element method is used to model the processes of shoaling and breaking of solitary waves on various slopes. Empirical formulae that can be used to characterize the breaking of solitary waves are presented. These include the breaking index, the wave height, the water depth, and the maximum particle velocity at the point of breaking. Comparisons with the results of other researches are given. 相似文献
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Nelson pointed out that the wave breaking criterion(H/d)_b for gentle slopes(i<1/100),inwhich H is the wave height and d is the water depth at the breaking point,is smaller than that for beachslopes of i>1/100),i.e.,the value of(H/d)_b for gentle slopes may be smaller than 0.6.Goda indicatedthat the wave breaking criterion given by himself is a result based on theoretical study,so it should be alsocorrect and can be used for gentle beaches,i.e.,the value of(H/d)_b for gentle slopes may be still largerthan 0.7.By use of high order nonlinear wave theory,this problem is analyzed in this study and the reasonwhy there is a large difference between different studies is explained.Moreover,the bottom energy loss dur-ing wave propagation is considered and the critical slope for the absence of wave breaking is also analyzed. 相似文献
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Wang Yongxue
Professor State Key Laboratory of Coastal Offshore Engineering Dalian University of Technology Dalian 《中国海洋工程》1995,(1)
- In this paper, the solitary wave deformation along a gentle slope and the impact pressure, on the wall are investigated experimentally and the results are compared with numerical results obtained based on the volume of fluid (VOF) method. The topography used in the experiment consists of three segments. The left segment is a 1:4 slope, the middle segment 1 :SO slope and the right segment a horizontal bed. Both the wave heights and breaking points obtained from numerical simulation and experiments are in good agreement. Numerical results give reasonable pressure distributions of breaking waves on the wall. 相似文献
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护面是海堤和护岸的重要结构,直接抵御波浪作用,可采用人工块体、块石等,种类繁多。采用紧密排列方块石作为护面结构是一种景观性较好的型式,依据方块石厚度不同能抵御不同大小的波浪作用。干砌条石及干砌块石护面曾有一些规范给出过计算方法,但现行规范没有相关内容可供设计参考,已有计算方法的理论分析还存在不足。当波浪与斜坡堤相互作用时,方块石护面出现位移或脱落可能发生在波浪回落最低阶段、波浪破碎打击阶段及破后爬高水流作用阶段,通过研究得到了不同阶段波浪对方块石护面作用力的计算方法。在波浪回落最低阶段,考虑了护面及其下方垫层渗透性影响,通过理论分析建立了低渗透护面浮托压强计算模型,采用物模试验将计算结果与试验测量值进行了对比分析,结果表明总体趋势符合,量值接近;在波浪破碎冲击阶段,基于射流冲击作用原理,提出了波浪在斜坡面破碎冲击压强计算方法,通过试验分析了波浪破碎水深波高比与破波相似参数的关系,利用浅水波理论计算了波浪破碎冲击水流流速;在爬高水流作用阶段,提出了水流引起的方块石护面垂直浮托力及水平拖曳力的计算方法,通过试验结果拟合了浮托力系数和拖曳力系数,验证了水流作用下护面的受力特征。最后,针对方块... 相似文献