数值波浪水槽消波器的改进与检验

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。     

Parabolic Wave Propagation Modelling in Orthogonal Coordinate Systems

This paper presents a numerical model study of the propagation of water waves using the parabolic approximation of the mild-slope equation in the orthogonal coordinate system. Two types of coordinate systems are studied: (a) a general form of orthogonal coordinate system and (b) the conformal system, a special form of orthogonal coordinate system. Two typical examples, namely, expanded breakwaters and a circular channel, are studied to validate the model. First, the examples are studied by use of the general orthogonal coordinates. Then the same examples are computed by use of the confonnal system. The computational results show that the confonnal coordinate system generally gives better predictions than the general orthogonal system. A numerical technique for generating the conformal grid is combined with the numerical model to improve the practicability of the model. The comparison between the result from the numerical grid system and that from the analytical grid system shows that reliable computational results can be obtained by use of the numerical confonnal grid system.     

双层局部开孔板沉箱对波浪反射的理论研究

提出了一种用于研究由双层开孔板和一个不透水后板的开孔结构对斜向波反射率的理论分析方法。整个流域被分成三个子域，在每个子域内应用特征函数展开法以得到该域内包含未知展开系数的势函数的表达式，在速度势的展开中，考虑了非传播模态波浪的影响。通过匹配开孔板处的边界条件可以求解待定的展开系数，继而求解双层开孔板防波堤结构对斜向波的反射率。数值计算结果与试验结果进行了比较，符合较好。并进一步讨论了几个重要因素对反射系数的影响。     

Second-Order Solutions for Random lnterfacial Waves Under Steady Uniform Currents

In the present research, the study of Song (2004) for random interracial waves in two-layer fluid is extended to the case of fluids moving at different steady uniform speeds. The equations describing the random displacements of the density interface and the associated velocity potentials in two-layer fluid are solved to the second order, and the wave-wave interactions of the wave components and the interactions between the waves and currents are described. As expected, the extended solutions include those obtained by Song (2004) as one special case where the steady uniform currents of the two fluids are taken as zero, and the solutions reduce to those derived by Sharma and Dean (1979) for random surface waves if the density of the upper fluid and the current of the lower fluid are both taken as zero.     

高能波控陆架的风暴沉积和风暴层序——以澳大利亚东南部陆架为例

根据浅层地震和钻孔资科,将澳大利亚东南部研究地区高能波控陆架风暴沉积分为直立风暴层、叠瓦状风暴层、无序风暴层、水平风暴层和纹层状风暴层等五类.各类风暴层及风暴层与非风暴层组合而成悬移风暴层序、悬移-推移混合风暴层序和推移风暴层序三大类.中陆架风暴沉积与现今近岸和水下岸坡相似,岩性、岩相和古生物属海岸带,风暴沉积厚,底板埋深大,组成物质粗.推断中陆架风暴沉积当形成于冰后期海侵、该地带处在近岸带和水下岸坡环境时,此时海面上升速度可能减缓,或趋近于零,甚至可能有短时间的下降.     

应用Boussinesq方程对由航道开挖所造成水深结构的变化产生的异常波况数值模拟研究

本文应用Ｂｏｕｓｉｎｅｓｑ方程采用有限差分法建立了非线性波浪数值模式，并应用该模式对由航道开挖所造成的水深结构变化对波浪传播产生的异常现象进行了数值模拟研究。从结果分析可知，这种异常波浪局部增大现象是由于入射波与航道夹角过小，使波浪无法折射入航道，而在航道两侧反射并与直接入射波叠加的结果。因此对于由水深的变化产生的波浪反射现象也是不可忽视的     

风暴期间黄河水下三角洲波浪变形

为确定适用黄河三角洲的波动理论，对黄河三角洲风暴期间及前后波浪连续观测资料进行了处理，将其投在komar波浪理论分区图中后，分析了风暴期间黄河水下三角洲波浪的波形特征，发现站位所在地适合的波浪理论主要为艾里波和斯托克斯波，风暴期间波浪变形，还存在少量超过极限波陡线的波浪，通过比较常见的极限波陡线，看出Miche曲线比较适合该研究区。     

波控弧形海湾近岸平衡剖面特征分析

应用Ｄｅａｎ，Ｂｏｄｇｅ和Ｌｅｅ近岸平衡剖面模式，对粤东靖海波控弧形海湾两种近岸剖面作了分析对比。结果显示推拟合的Ｄｅａｎ模式与实际剖面偏差明显，由Ｂｏｄｇｅ模式计算的凹度，北剖面小于南剖面，此与沿岩滩面坡度变化趋势一致，由Ｌｅｅ模式拟合的结果导出的波周期与实测值相近。     

减少航道外波浪集聚对策研究

进港航道开挖引起波能重新分布 ,导致航道外近区域波能聚集 ,波高增大 ,从而影响防波堤稳定及港内泊稳条件。文章介绍了 Boussinesq方程的推导过程和发展过程 ,基于深水和缓变地形的色散关系 ,建立了波浪数学模型。该模型可用于研究深水和浅水地区波浪的浅水变形、折射、绕射和反射。并提出了减少波能聚集、降低堤前波高的多种措施。结合大窑湾港实际工程 ,经过多方面的数物模比选 ,利用数学模型优化出一种可行的喇叭口航道开挖方案并付诸实施 ,降低了防波堤的堤前波高 ,满足了预期的设计要求。