共查询到19条相似文献，搜索用时 850 毫秒
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数值波浪水槽技术是一种新兴的水波动力学数值模拟技术, 它能够实现水波现象的精确模拟。作为数值波浪水槽的一个重要功能, 消波技术被用于消除传入波浪在水槽末端的反射效应, 以防止反射波对有效实验区域的污染, 从而保证特定要求的水波实验的精确性。目前被广泛采用的消波技术可分为阻尼消波区和主动消波器两类。 相似文献
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本文在时域非线性数值波浪水槽中，研究了不同风速条件下极端波浪的特性。采用推板造波的方式生成非线性波浪，基于Jeffrey遮蔽理论将风压项引入自由面动力学边界条件来模拟风压作用，通过高阶边界元法和混合欧拉-拉格朗日时间步进法来求解初边值问题。通过与已发表的聚焦波群实验结果对比验证了该数值模型的准确性，并研究了风压对极端波浪的最大波高、聚焦位置的偏移和波浪谱的演变等波浪性质的影响。本文进一步在数值波浪水槽中引入均匀水流，来模拟风生流对波浪演变的影响。结果表明，风压的存在会少量增大极端波浪的最大波高，波浪的聚焦和解焦过程伴随着明显的能量传递，并且风生流进一步导致了波浪聚焦位置的偏移。 相似文献
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本文基于具备间断捕捉能力的二阶全非线性Boussinesq数值模型,对规则波和随机波在礁坪地形上的传播变形进行了数值模拟。该模型采用高阶有限体积法和有限差分方法求解守恒格式的控制方程,将波浪破碎视为间断,同时采用静态重构技术处理了海岸动边界问题。重点针对礁坪上波浪传播过程中的波高空间分布和沿程衰减,礁坪上的平均水位变化,以及波浪能量频谱的移动和空间差异等典型水动力现象开展数值计算。将数值结果与实验结果对比,两者吻合情况良好,验证了模型具有良好的稳定性,具备模拟破碎波浪和海-岸动边界的能力,能较为准确地模拟波浪在礁坪地形上的传播过程中发生的各种水动力现象。 相似文献
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波浪谱形对不规则波数值模拟的影响 总被引：1，自引：0，他引：1
通过数值模拟分析了波浪谱形对不规则波浪数值模拟结果的影响.采用不同参数的JONSWAP谱模拟入射波要素,基于抛物型缓坡方程模拟不规则波浪的传播,分析了波浪谱形状对波浪数值模拟结果的影响.结果表明,采用抛物型缓坡方程模拟不规则波浪时,入射波浪谱形对模拟结果影响不明显;但由于模型中非线性项的影响,采用不规则波模拟的波高分布和采用规则波模拟的结果略有差别. 相似文献
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波浪在斜坡地形上破碎,破波后稳定波高多采用物理模型试验方法进行研究,利用近岸波浪传播变形的抛物型缓坡方程和波能流平衡方程,导出了适用于斜坡上波浪破碎的数值模拟方法。首先根据波能流平衡方程和缓坡方程基本型式分析波浪在破波带内的波能变化和衰减率,推导了波浪传播模型中波能衰减因子和破波能量流衰减因子之间的关系;其次,利用陡坡地形上的高阶抛物型缓坡方程建立了波浪传播和波浪破碎数学模型;最后,根据物理模型试验实测数据对数值模拟的效果进行验证。数值计算与试验资料比较表明,该模型可以较好地模拟斜坡地形的波浪传播波高变化。 相似文献
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利用完全非线性数值波浪水槽技术研究水下平板与波浪的相互作用。假定水下平板厚度极薄、刚性,位于有限水深并且非常接近自由水面。应用四阶龙格库塔方法追踪每一时刻的波面形状,采用阻尼层来吸收反射波以保证算法的稳定性,同时引入平滑和重组的方法抑制自由表面控制点的较高梯度。通过对波浪与浮动圆柱相互作用的数值模拟证实了数值波浪水槽方法的有效性,计算结果与线性理论吻合良好。在波浪数值水槽方法中引入造波板模拟波浪产生并与水下平板发生相互作用,应用傅立叶解析方法对波面变形、波浪力作了分析。结果表明在板非常接近自由水面的情况下会表现出现很强的非线性,揭示了线性理论的局限性。 相似文献
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透空式防波堤周围的非线性波浪传播的数值模拟 总被引：1，自引：0，他引：1
对非线形波浪在透空式防波堤周围的波浪变形进行了数值模拟,在Boussinesq波浪方程中加入与透空建筑物有关的新的耗散项,从而界定了透空建筑物引起的部分反射和透射,波浪折射衍射的传播过程通过控制方程求解。波浪控制方程通过有限差分方法求解。模型应用于模拟波浪经过具有部分反射的群桩式透空结构,结果表明透空式防波堤可以有效地衰减波浪,是重力式结构的一种替代形式。 相似文献
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《中国海洋大学学报(自然科学版)》2016,(10)
本文基于Navier-Stokes方程和连续性方程,利用VOF方法捕捉自由液面和松弛造波法实行造波,建立基于黏性流体理论的三维数值波浪水槽,并在该数值波浪水槽内对圆柱周围的波浪爬升效应进行数值模拟。选用两种不同的波浪参数,探讨波陡参数对柱体周围的波浪爬升效应及其所受载荷的影响。与势流模型相比,本文采用的黏性流模型可以较好的捕捉实验中出现的二次波峰现象。计算表明,本文建立的数值水槽可以较好用于直立圆柱波浪爬升问题的计算。 相似文献
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中咀湾是一个天然的避风良港,一般情况下外海波浪影响很小,主要受局部风场产生的局部风浪影响。本文采用曹宏生在Massel的扩展缓坡方程基础上推导出来的考虑陡变地形和能量耗散效应的缓坡方程为控制方程,结合固边界的反射边界条件,构成波浪传播变形的联合折射、绕射和反射的数学模型。文中将此方法运用在中国台州市大陈岛中咀湾避风港中,用波浪数学模型计算极端高水位和设计高水位时3种波况分别在3组重现期时工程海域的波浪要素,提供防波堤的堤前波高,并分析比较此处实心式和透空式防波堤的防浪性能。 相似文献
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Recently the numerical wave tank has become a widely-used tool to study waves as well as wave-structure interactions, and the wave-absorbing method is very important as its effect on the quality of waves generated. The relaxation method and the derived momentum source method are often utilized, however, the damping weight is constant during calculation and repeated trials are required to obtain an acceptable wave-absorbing effect. To address the above- mentioned issues, a conserved wave-absorbing method is developed. The damping weight is determined by solving the mass conservation equation of the absorbing region at every time step. Based on this method, a two-dimensional numerical wave tank is established by using the VB language to simulate various waves by which the validation of this method is evaluated. 相似文献
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Numerical Modeling of Wave Diffraction-Refraction in Water of Varying Current and Topography 总被引：3，自引：1，他引：2
FENG Weibing 《中国海洋工程》2000,14(1):45-58
—A numerical model for wave diffraction-refraction in water of varying current and topogra-phy is proposed,and time-dependent wave mild-slope equation with a dissipation term and correspondingequivalent governing equations are presented.Two different expressions of parabolic approximations forthe case of the absence of current are also given and analyzed.The influence of current on the results ofsimulation of waves is discussed.Some examples show that the present model is better than others in simu-lating wave transformation in large water areas.And they also show that the influence of current shouldbe taken into account,on numerical modeling of wave propagation in water of strong current and coastalareas,otherwise the modeling results will be largely distorted. 相似文献
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波浪与带窄缝方箱作用共振现象的数值模拟 总被引：1，自引：1，他引：0
By introducing a source term into the Laplace equation, a two-dimensional fully nonlinear time-domain numerical wave flume (NWF) is developed to investigate the resonance induced by the interaction bet... 相似文献
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Application of desingularized approach to water wave propagation over three-dimensional topography 总被引：1，自引：0，他引：1
A numerical approach based on desingularized boundary element method and mixed Eulerian–Lagrangian formulation [Zhang et al., 2006. Wave propagation in a fully nonlinear numerical wave tank: a desingularized method. Ocean Engineering 33, 2310–2331] is extended to solve the water wave propagation over arbitrary topography in a three-dimensional wave tank. A robust damping layer applicable for regular and irregular incident waves is employed to minimize the outgoing wave reflection back into the wave tank. Numerical results on the propagation of regular and irregular incident waves over the flat bottom and linear incident waves over an elliptical shoal show good concurrence with the corresponding analytical solutions and experimental data. 相似文献
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《Coastal Engineering》2006,53(2-3):149-156
Wave setup can contribute significantly to elevated water levels during severe storms. In Florida we have found that wave setup can be 30% to 60% of the total 100-year storm surge. In areas with relatively narrow continental shelves, such as many locations along the Pacific Coast of the United States, wave setup can be an even larger proportionate contributor of anomalous water levels during major storms. Wave setup can be considered as comprising two components, with the first being the well-known static wave setup resulting from the transfer of breaking wave momentum to the water column. The second, oscillating component, is a result of nonlinear transfer of energy and momentum from the primary (linear) spectrum to waves with length and time scales on the order of the wave groups.Static wave setup is the focus of this paper with emphasis on effects due to internal or surface forces that act on the wave system and cause both dissipation of wave energy and transfer of momentum. In particular, the effects of wave damping by vegetation and bottom friction are considered. Linear wave theory is applied to illustrate these effects and, for shallow water waves, the setup is reduced by two-thirds the amount that would occur if the same amount of energy dissipation occurred in the absence of forces. Effects of nonlinear waves are then considered and it is found, for a shallow water wave of approximately one-half breaking height, that a wave setdown rather than setup occurs due to damping by vegetation and bottom friction.The problem of wave setup as waves propagate through vegetation was stimulated by studies to establish hazard zones associated with 100-year storm events along the shorelines of the United States. These storms can generate elevated water levels exceeding 4 to 6 m and can result in overland wave propagation. As these waves propagate through vegetation and damp, the question arose as to the contribution of this process to elevated mean water levels through additional wave setup. 相似文献
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内孤立波具有振幅尺度大、能量集中的特点,其引起流场和密度场的迅速变化可能对海洋工程结构物以及水下潜体造成严重威胁。因此研究不同造波条件下生成的内孤立波运动的流场特征具有重要的学术意义和实际应用价值。采用直接数值模拟方法和给定的初始密度场密度跃迁函数,对重力塌陷激发内孤立波的运动过程进行研究,探讨了不同造波条件下,激发产生的内孤立波波型、涡度、振幅和水平速度等流场特征。结果表明:(1)直接模拟数值方法能够模拟内孤立波传播过程中的密度界面波型反转现象;(2)从定性和定量的角度,证实了不稳定内孤立波传播过程中存在能量的向后传递;(3)对于相同的台阶深度(水闸两侧初始密度界面的高度差),初始涡流保持相同,但是随着上下层水深比的减小,其强度下降显著;(4)台阶深度对初始涡流的垂直结构的影响要大于上下层水深比,且台阶深度对内孤立波的振幅、水平速度的影响显著。 相似文献
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Owing to the interactions among the complex terrain, bottom materials, and the complicate hydrodynamics, typhoon waves show special characteristics as big waves appeared at the high water level(HWL) and small waves emerged at low and middle water levels(LWL and MWL) in radial sand ridges(RSR). It is assumed that the mud damping, sandy bed friction and wave breaking effects have a great influence on the typhoon wave propagation in this area. Under the low wave energy, a mud layer will form and transport into the shallow area, thus the mud damping effects dominate at the LWL and the MWL. And high Collins coefficient(c around 1) can be applied to computing the damping effects at the LWL and the MWL. But under the high wave energy, the bottom sediment will be stirred and suspended, and then the damping effects disappear at the HWL. Thus the varying Collins coefficient with the water level method(VCWL) is implemented into the SWAN to model the typhoon wave process in the Lanshayang Channel(LSYC) of the RSR, the observed wave data under "Winnie"("9711") typhoon was used as validation. The results show that the typhoon wave in the RSR area is able to be simulated by the VCWL method concisely, and a constant wave breaking coefficient(γ) equaling 0.78 is better for the RSR where wide tidal flats and gentle bed slopes exist. 相似文献