共查询到18条相似文献,搜索用时 875 毫秒
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SWASH模型是一种新型的非静压时域波浪模拟。为了探讨SWASH模型对于解决近岸波浪传播变形问题的适用性,在对其控制方程、边界条件、数值解法等进行介绍的基础上,采用该模型分别模拟了正向规则波、斜向规则波和斜向不规则波入射条件下L形防波堤附近水域的波浪场和波生流场,并与物理试验结果进行对比。结果表明,SWASH模型较好地复演了波浪在近岸区域所发生的浅水变形、折射、破碎,以及堤前反射、堤内绕射等物理现象,波高沿断面的定量分布与试验结果吻合良好,同时较好地模拟了不同波况下防波堤附近水域的波生流场,说明该模型适用于复杂岸线和地形条件下波浪传播变形的数值模拟。 相似文献
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通过在波浪水槽中进行物理模型试验,研究相对半径、波陡、水深以及开孔率对新型反弧形面防波堤消浪效果的影响,以评价这种新型防波堤的消能效果.研究结果表明:反弧形防波堤的反射系数随相对半径的增大而减少,随波陡的变化则较为复杂;而防波堤的透射系数则变化较小并且维持较低数值;在不开孔时,反弧形防波堤在低水位的消浪效果较好,开孔后,在高水位时的消浪效果要好. 相似文献
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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
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基于Fluent平台建立了可用于波浪传播模拟的数值计算水槽,利用不同波浪参数的线性规则波模拟分析了网格尺度L/Δx对产生波浪质量的影响,确定数值水槽的网格划分尺度,并验证了阻尼消波的有效性。在此基础上,用模拟频谱的方法对聚焦波浪的传播进行了数值模拟,通过数值模拟与物理试验不同位置处的聚焦波波面和聚焦点下水质点速度时间过程线对比,验证了模拟频谱方法数值计算的有效性。进一步对聚焦波浪与直立圆柱的作用进行了数值模拟,数值模拟聚焦波面过程、聚焦波浪水质点速度、圆柱周围波浪波动过程、圆柱上所受的波压力等,并与试验结果进行了对比,数值计算结果与试验结果吻合很好,验证了所建立的数值水槽的有效性。对聚焦波波面和压力特征值进行了误差分析,并分析了误差的产生原因,为进一步研究聚焦波浪与工程结构物的作用奠定基础。 相似文献
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计算域中存在直立岛式结构物时波浪传播的数值模拟 总被引:3,自引:1,他引:2
针对计算域中存在直立岛式结构物的复连通区域,提出了岛体边界条件,利用缓坡方程建立了在计算域中存在直立岛式结构物时波浪传播的数值模拟模型。模型适用于变水深水域问题,克服了解析解只能适用于等水深水域的不足。直立圆柱和无穷小厚度岛式防波堤周围波浪传播的数值算例表明,数值解与解析解吻合良好,说明所建立的数值模拟模型能有效地模拟复连通区域内的波浪传播。矩形固定式防波堤周围波浪场的数值模拟说明该模型对工程实际有较强的适应性。 相似文献
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为给河口海岸防护工程设计和地形演变预测提供科学依据,研究了波浪从外海向近岸传播过程中在一定地形条件下产生的布拉格共振现象。介绍了波浪布拉格共振的定义、特征和研究意义,评述了现场观测、理论研究、水槽试验、数值模拟等4种研究方法的优缺点,总结了波浪布拉格共振类型、低阶共振反射系数公式和高阶共振数值模拟的研究成果,提出了波浪布拉格共振主频下移、不规则波布拉格共振特性、波流相互作用下布拉格共振机理等3个亟待深入研究的课题。 相似文献
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高雷诺数下带自由表面的重力波的有限元数值模型 总被引:5,自引:3,他引:2
本文基于扩展的虚拟浓度和Sommerfeld线性辐射边界条件建立了数值波浪水槽。用有限元方法结合大涡模拟(LES)湍流模型在Euler坐标系统中求解了二维不可压粘性流体的N-S方程,而自由表面函数方程是在沿流体质点迹线定义的Lagrange系统中求解的。为了检验该数值波浪模型的有效性,本文中用该数值波浪水槽进行了海底管线在波浪场中受力的数值实验,并与物模实验的结果做了对比,其雷诺数Re为10700。 相似文献
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潜堤透浪系数是衡量潜堤削弱波浪能力的主要指标。基于Boussinesq型方程的MIKE21-BW模型建立波浪数值水槽,进行规则波作用下潜堤透浪系数的数值模拟。根据Dingemans物理模型试验结果对BW模型进行参数率定和验证,验证结果良好。在此基础上,进一步分析了影响潜堤透浪系数的无因次影响参数,包含相对淹没深度、波陡、相对堤顶宽度、斜坡堤坡度等,研究不同因素组合情况下潜堤透浪系数的变化规律。建立了规则波作用下潜堤透浪系数的计算式,应用MATLAB数学软件对式中的系数进行拟合,拟合式计算值与BW模型计算值相关系数为0.858,相关性较好。另外,将拟合式与杨正己公式进行比较,并分析数据的差异与原因。研究表明:MIKE21-BW模型可以进行规则波作用下潜堤透浪系数的数值模拟。 相似文献
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WANGGuo-yu WANGYong-xue LIGuang-wei 《水动力学研究与进展(B辑)》2005,17(2):228-233
A new kind of open type breakwaters was proposed based on the concept of wave energy conversion. The excellent feature of the structure is that it can absorb and utilize the wave energy to dissipate waves. The effects of some factors, such as the configuration insides, the geometrical parameters and the relative width (the ratio of the width to the wave length), on the performance of the breakwater were discussed based on a series of regular wave tests in the wave flume. The hydrodynamic characteristics of the new open type breakwater were analyzed in detail, and the structure was optimized to improve the performance of the breakwater to effectively dissipate the waves with long period. The variation of the coefficients of wave transmission and reflection along with attenuation with respect to relative width was examined. The results of the physical model tests indicate that the transmission coefficient significantly decreases by about twenty percent at the range of relative width from 0. 1 to 0.2, compared with the traditional open type breakwaters. 相似文献
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《水动力学研究与进展(B辑)》2017,(2)
A theoretical approach is derived to study interaction of linear water waves with an air bubble curtain used as a pneumatic breakwater. Modelling of wave transmission through an aerial barrier is a complex task due to a need to cover processes associated with wave-current interaction, effects of two-phase flows, wave damping, etc.. An initial boundary-value problem is solved by applying an efficient eigenfunction expansion method and a time-stepping procedure. The derived semi-analytical solution is used to study the effect of basic parameters of the model on wave dissipative properties of the pneumatic breakwater. Results show that wave damping by the breakwater is mainly affected by an air flow rate. The increased air discharge results in higher velocities of ascending bubbles and increases aerial barrier width. This leads to a substantial reduction of transmitted wave heights, especially for waves of intermediate length and short waves. In order to verify the applicability of the presented theoretical approach, laboratory experiments are conducted in a wave flume for different wave regimes and pneumatic breakwater characteristics. The analysis of a wave transmission coefficient calculated numerically and measured in the laboratory confirms that the derived model can be used for a certain range of wave conditions. 相似文献
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New empirical formulas of the transmission coefficient for permeable breakwaters were suggested based on available experimental data regarding the low-crest structure(LCS), including the permeable rubble mound breakwater and pile-type breakwater. The rationality of the present formulas was verified by their comparison with existing empirical and analytical formulas. Numerical flume results were obtained by solving the modified Boussinessq-type wave equations(MBEs), and a new expression relating the friction coefficient α to the relative submerged depth t sR H was also derived. Comparative analysis shows that the results of the present formulas agree with the numerical flume results as well as available experimental data, and the present formulas are superior to the existing empirical and analytical expressions in estimating the transmission coefficient. The present formulas can provide references for estimation of the transmission coefficient in engineering practice. 相似文献
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ZHOU Bin-zhen NING De-zhi TENG Bin CHEN Li-fen 《水动力学研究与进展(B辑)》2010,22(3):402-409
Based on the eigenfunction expansion technique, the wave generation by a piston wave maker in a wave flume with a partially reflecting end-wall is studied. The corresponding velocity potential and wave elevation in the flume are obtained. The present analytical solution is verified by the numerical results obtained from a time-domain higher-order boundary element method in a closed flume. Numerical experiments are further carried out to study the difference between the partial/full reflection boundary and the transmission boundary and the effects of the reflection coefficient and the motion period of the wave maker on the wave height. Meanwhile, the natural frequency of the wave flume can be obtained from the analytical expression. The resonance occurs when the motion frequency is equal to the natural frequency. Even the partial reflection of the end-wall in the wave flume experiments has a great influence on the wave height, therefore, inaccurate measurements would be resulted in long-time simulations, especially when the wave frequency approaches the wave flume natural frequency. The present study can serve as a guidance for the physical experiment in wave flumes. 相似文献
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通过物理模型试验和数值模拟试验,对前倾斜、后垂直的双挡浪板桩基透空堤的透射系数、反射系数、波压力,以及波浪爬高等水动力特性进行了系统的数值模拟研究。研究结果表明,相较于垂直挡浪板,采用倾斜的前挡浪板可明显减小结构的透射系数和反射系数,而波压力和波浪爬高变化不大,体现了更好的挡浪效果。随着挡浪板倾斜角度加大,透射系数、反射系数均呈减小趋势,当挡浪板倾斜角度增大至40°后,透射系数变化基本趋于平稳。总体来说,倾斜挡浪板结构优于垂直挡浪板结构,综合考虑各个因素,建议工程中前挡浪板倾斜角度以不大于40°为宜。 相似文献
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为提高透空式防波堤的消浪效果,提出了一种新型透空格栅板式防波堤结构。通过水槽试验,分析了该防波堤的消波性能,探讨了上下层平板相对间距以及格栅板间隙比等参数对防波堤透射系数和反射系数的影响。结果表明,该结构防波堤消波性能良好,且防波堤出水状态下的消浪效果要好于淹没状态;随着相对板间距的增大,防波堤透射系数变小;上下层各格栅板间隙比为0.1时,防波堤的消波效果最佳。 相似文献