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111.
In this study,an advanced probabilistic neural network(APNN)method is proposed to reflect the global probability density function(PDF)by summing up the heterogeneous local PDF which is automatically determined in the individual standard deviation of variables.The APNN is applied to predict the stability number of armor blocks of breakwaters using the experimental data of van der Meer,and the estimated results of the APNN are compared with those of an empirical formula and a previous artificial neural network(ANN)model.The APNN shows better results in predicting the stability number of armor blocks of breakwater and it provided the promising probabilistic viewpoints by using the individual standard deviation in a variable.  相似文献   
112.
The objective of the present study is to develop a volume of fluid (VOF)-based two-phase flow model and to discuss the applicability of the model to the simulation of wave–structure interactions. First, an overview of the development of VOF-type models for applications in the field of coastal engineering is presented. The numerical VOF-based two-phase flow model has been developed and applied to the simulations of wave interactions with a submerged breakwater as well as of wave breaking on a slope. Numerical results are then compared with laboratory experimental data in order to verify the applicability of the numerical model to the simulations of complex interactions of waves and permeable coastal structures, including the effects of wave breaking. It is concluded that the two-phase flow model with the aid of the advanced VOF technique can provide with acceptably accurate numerical results on the route to practical purposes.  相似文献   
113.
Wave interaction with T-type breakwaters   总被引:1,自引:0,他引:1  
The wave transmission, reflection and energy dissipation characteristics of partially submerged ‘T'-type breakwaters (Fig. 1) were studied using physical models. Regular and random waves, with wide ranges of wave heights and periods and a constant water depth were used. Five different depths of immersions of the ‘T'-type breakwater were selected. The coefficient of transmission, Kt, coefficient reflection, Kr, were obtained from the measurements and the coefficient of energy loss, Kl is calculated using the law of conservation of energy. It is found that the coefficient of transmission generally reduces with increased wave steepness and increased relative water depth, d/L. This breakwater is found to be effective closer to deep-water conditions. Kt values less than 0.35 is obtained for both normal and high input wave energy levels, when the horizontal barrier of the T type breakwater is immersed to about 7% of the water depth. This breakwater is also found to be very efficient in dissipating the incident wave energy to an extent of about 65% (i.e. Kl>0.8), especially for high input wave energy levels. The wave climate in front of the breakwater is also measured and studied.
Full-size image (12K)
Fig. 1. Schematic view of the T-type breakwater.  相似文献   
114.
This paper proposes ten types of improved floating breakwaters for experiment with regular waves, based on the experience in the development and manufacture of existing floating breakwaters both at home and abroad, and on the results of experimental studies on the hydraulic characteristics of several types of floating breakwaters. The wave heights before and behind the breakwaters are measured, the movements of floating breakwaters are observed and the chain forces of the floating breakwaters are measured. The paper studies and compares the hydraulic characteristics of the improved rectangular floating breakwaters of which the internal and external structures and their installation methods are changed. Finally the optimal type of structure is selected through experiments.  相似文献   
115.
以淹没状态下的半圆型防波堤为研究对象,采用不规则波断面模型试验,结合典型实例分析了堤体波压分布的特点,指出波浪经过堤顶破碎与否直接影响到堤体所受波力的大小,并建议了开孔办法和波力计算方法.  相似文献   
116.
-The construction of breakwaters in China in more than 40 years since the founding of the People's Republic of China is reviewed. The construction of two main types of breakwater, upright breakwaters and rubble mound breakwaters, and the way in which they are built are expounded. Recommendations to improve the technology for future breakwater construction are presented.  相似文献   
117.
本文基于1987和1988年夏季在古镇口港同步连续观测的波浪、波压力和浮托力资料,分析研究了浮托力的概率特征、浮托力沿堤底面的变化及其谱特征。结果表明,浮托力幅度和周期的累积分布实际上不随测点在堤底面上的位置变化,可用公式表示。浮托力沿堤底面宽度近似呈线性衰减,前趾浮托力最大,后趾不为零,呈梯形状。文中还给出了计算最大峰、谷总浮托力的方法。  相似文献   
118.
扭王字块体护面斜坡堤越浪量试验研究   总被引:2,自引:1,他引:1  
针对现行规范中缺少扭王字块体护面斜坡堤越浪量的计算方法,考虑波陡、相对水深、相对堤顶超高、相对坡肩宽度、相对胸墙高度和相对块体尺寸等影响因素,通过波浪水槽物模试验,运用多元回归方法,给出了扭王字块体斜坡堤越浪量中护面结构影响系数和平均越浪量的计算公式。与试验值和其它计算公式进行了验证对比,结果基本吻合,具有一致性的规律。研究成果丰富了规范内容,对斜坡堤工程设计具有重要参考意义。  相似文献   
119.
基于微幅波绕射理论,应用特征函数展开法,推导了双层直立圆弧型透空防波堤的波浪绕射解析解,从而将已有的比例边界有限元法拓展为解析算法,并据此对外层与内层防波堤所受波浪载荷进行了解析计算。计算结果表明:应用本文方法对直立透空圆环柱的绕射波浪载荷进行验证计算,所得结果与现有的解析解完全吻合,说明方法可靠。双层堤较单层堤能更有效地减弱波浪作用。波浪的入射角度和特征参数、防波堤张角与半径、防波堤透空系数以及水深等因素的相对变化对双层堤的波浪作用均存在一定影响。  相似文献   
120.
A pile-restrained pontoon-plate floating breakwater is proposed in this paper.The laboratory physical-model tests are conducted to investigate the wave-dissipation property and heave-motion response of a model.The influence of the model′s geometric parameters including relative pontoon width,plate width,number of plates and pontoon draft on wave-dissipation performance and heave-motion response are discussed,as well as the correlation between these two factors.The result indicates that wave-dissipation performance of the proposed structure is better than the pontoon structure:its transmission coefficient and heave-motion height are reduced by 0.2 and 0.3,respectively,in comparison with those of the pile-restrained pontoon model at a relative pontoon width of 0.2.  相似文献   
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