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1.
Experimental and Theoretical Investigation of Wave Forces on A Partially-Perforated Caisson Breakwater with A Rock-Filled Core 总被引：2，自引：0，他引：2
1.IntroductionVertical breakwaters are widely used for harbor and coastline protection in coastal engineering.Recently,perforated breakwaters have been often used in practice as they can effectively reduce thewaveforces actingon,the wave reflectionfromand… 相似文献
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W. Koterayama 《Ocean Engineering》1980,7(3):399-412
This paper presents a method of estimating wave forces acting on a submerged horizontal circular cylinder fixed in oblique waves.The experiments show that drag and inertia coefficients in beam sea are available for calculating the wave forces in oblique waves.Wave forces exerted on a vertical circular cylinder in deep waves are also investigated.The experimental results show that wave forces acting on the vertical cylinder coincide approximately with hydrodynamic forces acting on a submerged circular cylinder in an oscillating fluid. 相似文献
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In this study, the total horizontal and vertical forces as well as the phase differences of irregular waves on a partially perforated caisson breakwater are investigated. The partially perforated caisson is located on a rubble fill foundation and filled with rock. Based on linear potential theory, a simple semi-analytical solution of the present problem is developed by means of the matched eigenfunction method and the finite element method. Experimental tests are also conducted to validate the theoretical model and examine the wave forces acting on the perforated caisson. The effects of some of the main factors on the total wave forces and the phase difference are examined. Theoretical and experimental studies show that when the total horizontal force reaches its peak, the simultaneous total vertical (upward) force is rather small or even becomes downwards. This is due to the existence of an obvious phase difference between the time histories of the total horizontal and vertical forces, which is an important advantage of perforated caissons over traditional structures. 相似文献
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圆柱形沉浮式深海养殖网箱的受力分析 总被引：9，自引：0，他引：9
应用一系列力学关系，研究了深海圆柱形沉浮式养殖网箱所承受的波浪力情况。导出深海沉浮式养殖网箱的运动方程，并给出数值计算。在网箱波浪力的研究中采用绕射理论和Morison方程，讨论了在波高、波长及周期变化下水动力的变化趋势，得出网箱所受到的水平波浪力远大于竖直波浪力，波高的变化对波浪力的影响最大的结论，为深海网箱的设计校核提供1种参考方法。 相似文献
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通过正向与斜向波浪对半圆型防波堤(不开孔出水堤)的实验研究,给出了其水力特性及单位堤长所受的无因次水平波浪力、竖向波浪力和波浪浮托力随各主要影响因素的变化规律,特别指出了斜向波浪力可大于正向波浪力及水平波浪力中波谷作用大于波峰作用发生的条件。 相似文献
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Numerical Analysis on the Effects of Submerged Depth of the Grid and Direction of Incident Wave on Gravity Cage 总被引：1，自引：0，他引：1
In this paper,the numerical model of the net cage with the grid mooring system in waves is set up by the lumped mass method and rigid kinematics theory,and then the motion equations of floating system,net system,mooring system,and floaters are solved by the Runge-Kutta fifth-order method.For the verification of the numerical model,a series of physical model tests have been carried out.According to the comparisons between the simulated and experimental results,it can be found that the simulated and experimental results agree well in each condition.Then,the effects of submerged depth of grid and direction of incident wave propagation on hydrodynamic behaviors of the net cage are analyzed.According to the simulated results,it can be found that with the increase of submerged depth of grid,the forces acting on mooring lines and bridle lines increase,while the forces on grid lines decrease;the horizontal motion amplitudes of floating collar decrease obviously,while the vertical motion amplitudes of floating collar change little.When the direction of incident wave propagation changes,forces on mooting lines and motion of net cage also change accordingly.When the propagation direction of incident wave changes from 0° to 45°,forces on the main ropes and bridle ropes increase,while the forces on the grid ropes decrease.With the increasing propagation direction of incident wave,the horizontal amplitude of the forces collar decreases,while the vertical amplitude of the floating collar has little variation. 相似文献
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ＴｈｅｉｒｒｅｇｕｌａｒｂｒｏｋｅｎｗａｖｅｆｏｒｃｅｓｏｎｖｅｒｔｉｃａｌｗａｌｌＬｉＹｕｃｈｅｎｇ,ＬｉｕＤａｚｈｏｎｇ,ＱｉＧｕｉｐｉｎｇ,ＳｕＸｉａｏｊｕｎ（ＲｅｃｅｉｖｅｄＡｐｒｉｌ２１,１９９７,ａｃｃｅｐｔｅｄＪｕｌｙ２,１９９７）Ａｂ... 相似文献
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斜向不规则波对直墙作用的实验研究 总被引：5，自引：1，他引：5
通过长峰不规则波和方向波谱对直墙作用的实验研究 ,分别给出了每延米斜向不规则波波浪力与正向力之比 ,方向波谱波浪力与斜向长峰不规则波波浪力之间的关系 ,通过与规则波实验结果的比较给出了斜向规则波与不规则波波浪力之间的相对关系 ;并对斜向不规则波的反射系数与正向波时的变化作出了分析 相似文献
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《中国海洋工程》2021,(4)
Wave forces on two side-by-side boxes in close proximity under wave actions were analyzed using the OpenFOAM package. The upstream box heaved freely under wave actions, whereas the downstream box remained fixed. For comparison, a configuration in which both boxes were fixed was also considered. The effects of the heave motion of the upstream box on the wave loads, including the horizontal wave forces, vertical wave forces, and moments on the boxes, were the focus of this study. Numerical analyses showed that all frequencies at which the maximum horizontal wave forces, maximum vertical wave forces, and maximum moment appeared are dependent on the heave motion of the upstream box and that the effects of the heave motion on these frequencies are different. Furthermore,these frequencies were observed to deviate from the corresponding fluid resonant frequency. Moreover, the heave motion of the upstream box reduced the wave forces acting on both boxes and altered the variation trends of the wave forces with the incident wave frequency. 相似文献
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张力腿平台内孤立波作用特性数值模拟 总被引：1，自引：1，他引：0
依据三类内孤立波理论KdV、eK dV和MCC的适用性条件,采用Navier-Stokes方程为流场控制方程,以内孤立波诱导上下层深度平均水平速度作为入口边界条件,建立了两层流体中内孤立波对张力腿平台强非线性作用的数值模拟方法。结果表明,数值模拟所得内孤立波波形及其振幅与相应理论和实验结果一致,并且在内孤立波作用下张力腿平台水平力、垂向力及力矩数值模拟结果与实验结果吻合。研究同时表明,张力腿平台内孤立波载荷由波浪压差力、粘性压差力和摩擦力构成,其中摩擦力很小,可以忽略;水平力的主要成分为波浪压差力和粘性压差力,粘性压差力与波浪压差力相比较小却不可忽略,流体粘性的影响较小;垂向力中粘性压差力很小,流体粘性影响可以忽略。 相似文献
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Wave forces on a vertical truncated circular cylinder in Stokes waves with the wave slopes ranging from 0.06 to 0.24, are measured in a wave tank. The higher harmonic wave forces are compared with the available values from theories of the FNV (Faltisen–Newman–Vinje) model and Varyani solution. The first harmonic horizontal forces measured are much larger than the theoretical values from the FNV model, while the first harmonic vertical forces are well predicted by the Varyani theory. It was also found that the FNV model significantly overpredicts the second harmonic horizontal forces in high frequency waves, but under predicts the third harmonic forces. The differences between the actual measurement and the theory, in the second and third harmonic horizontal forces, become smaller at low wave frequencies as the wave slope increases. In addition, the transverse instabilities in the incoming waves with high wave slope were observed, which is due to the nonlinear modulation. Measurements were, thus, carried out before the instability occurred. 相似文献
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Based on rigid kinematics theory and lumped mass method,a mathematical model of the two net cages of grid mooring system under waves is developed.In order to verify the numerical model,a series of physical model tests have been carried out.According to the comparisons between the simulated and the experimental results,it can be found that the simulated and the experimental results agree well in each wave condition.Then,the forces on the mooring lines and the floating collar movement are calculated under different wave conditions.Numerical results show that under the same condition,the forces on the bridle ropes are the largest,followed by forces on the main ropes and the grid ropes.The horizontal and the vertical float collar motion amplitudes increase with the increase of wave height,while the relationship of the horizontal motion amplitude and the wave period is indistinct.The vertical motion amplitude of the two cages is almost the same,while on the respect of horizontal motion amplitude,cage B(behind cage A,as shown in Fig.4) moves much farther than cage A under the same wave condition.The inclination angle of the floating system both in clockwise along y axis and the counter one enlarges a little with the increase of wave height. 相似文献
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基于粘性流模型的筒型基础防波堤波浪力数值分析 总被引：3，自引：0，他引：3
筒型基础防波堤是一种新型港口海岸工程结构,其基础上部是由连续排列的圆筒构成的直立防浪墙.采用粘性流数值模型,研究连续圆筒防波堤上波浪力竖向分布、水平(沿圆筒环向)分布和波浪力合力特性,并对粘性流数值模型计算的平面直墙波浪力与海港水文规范方法计算结果;粘性流数值模型计算的连续圆筒墙面波浪力与平面直墙波浪力;无限长连续圆筒墙面波浪力与有限长连续圆筒墙面波浪力进行比较分析.针对所选工程算例,建议按<海港水文规范>中平面直墙波浪力计算方法确定连续圆筒防波堤上的波浪力时,波峰时考虑0.90左右的折减系数,波谷时考虑0.95左右的折减系数. 相似文献
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消除"不规则频率"的非连续高阶元方法 总被引：2，自引：0，他引：2
针对使用边界元法计算波浪与结构物相互作用时所出现的“不规则频率”现象，采用连续高阶元和部分非连续高阶元对通过修改积分区域所获得的边界积分方程进行离散，有效地消除了“不规则频率”现象的发生。波浪作用下的截断圆柱所受到的水平波浪力和垂向波浪力的数值计算结果验证了该方法的有效性，同时考虑了非连续单元配置点的选择及单元划分数目对消除效果的影响。 相似文献
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Transmitted and reflected coefficients for horizontal or vertical plate type breakwater 总被引：2，自引：0，他引：2
Surface or submerged horizontal or vertical plate can be considered as a new concept breakwater.This paper investigates the wave-plate interaction of this type of breakwater by use of the boundary element method.The relationships of wave transmitted and reflected among plate thickness,submergence and length are carefully studied by numerical simulation.It is shown that:(1) The transmitted coefficients of submerged horizontal plate or vertical plate will become larger with the increase of plate thickness and reduce rapidly with the decrease of plate submergence.(2) Both surface horizontal and vertical plate are efficient for intermediate and short wave elimination,but vertical plate is more effective.(3) Submerged horizontal plate can act more effectively than submerged vertical plate does.With all wave frequencies,the vertical plate almost has no wave elimination effect. 相似文献
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Wave loads on a stationary floating bottomless cylindrical body with finite wall thickness 总被引：2，自引：0，他引：2
S.A. Mavrakos 《Applied Ocean Research》1985,7(4):213-224
This paper aims at presenting a method for solving the linearised diffraction problem of the interaction between regular sinusoidal, small amplitude incident waves and a bottomless cylindrical floating body with a vertical symmetry axis and finite wall thickness, through the idealisation of the flow field around the structure using ring elements. The horizontal and vertical excitation forces, the rolling moment, the resulting wave motion inside the cylinder, as well as the pressure distribution on the wetted surface of the structure are obtained by solving the diffraction boundary-value problem through the implementation of the Galerkin method. The analytical predictions are compared with other analytical results and pertinent experimental data. Finally, the influence of the wall thickness on the wave loads and the fluid motion inside the pond is examined. 相似文献
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研究具有窄谱和Ｗｅｉｂｕｌｌ波高分布的波群对非线性桩柱系统作用力的统计性质。求得了桩桩的波浪峰力的各种特征值及其比值。指出这些数值不仅是阻力一惯性力参数ｂＨ的函数，也随着波群因子而变化。本文模式更具广泛性。文中给出了一系列计算图表，可从理论计算波群作用于桩柱的波浪峰力。 相似文献