【作者】 马锡超；

【导师】 史宏达；

【作者基本信息】 中国海洋大学 ， 港口、海岸及近海工程， 2008， 硕士

【摘要】 波浪是近岸工程的主要动力因素之一,其计算一直深受重视。当外海深水区的风浪或涌浪传播至海岸附近的浅水区时,受水深、地形等因素的影响,波浪的传播速度、波长、波高、波面状况等将发生明显变化。由于浅水区是人类实践活动的主要区域,所以浅水区的波浪变化对近岸海洋环境、资源和工程建设等影响最大。在海岸工程项目中,波浪变形预报及波浪破碎引起的近岸区流场问题一直是海岸动力学的重要课题。建立一种高精度的近岸区波浪变形预报模型以及波浪破碎模型,不但具有很高理论价值,而且具有直接工程意义。同时,在波浪数值模拟中,不同护岸形式具有不同的反射率,因此,合理率定反射率在数值模拟中起着十分重要的作用。本论文在查阅国内外大量文献的基础上,概括总结了各种类型的波浪计算模型,以及数值模拟方法。论文在前人已有工作的基础上,采用能够模拟近海地区波浪变形的完全非线性Boussinesq波浪模型,对其进行了扩展,使之具备造波、消波、动边界处理的能力。同时本文采用预测一校正有限差分格式对拓展后的方程进行离散和求解。在方程数值求解过程中,本文引入了数值过滤技术,有效去除由于相互作用的非线性效应产生的极小波长谐波,保证了数值计算的精度。为验证模型适用性和精度,本文针对多个经典实验地形进行了数值模拟,并将所得结果与实验实测数据进行了比较,二者吻合良好,说明本文模型具有良好的适用性和足够的精度。同时,本文结合物理模型试验,基于两点法,研究了不同护岸形式的波浪发射率,探讨了其在波浪场数值模拟中的作用,为实际工程数值计算提供合理的边界波浪反射系数,提高了数值模拟的准确性。更多还原

【Abstract】 The wave is one of the main dynamical factors to offshore engineering. Its calculation is always regarded. When the wind wave or the swell at the deep water area of the open sea propagate to the shallow water area near the seacoast, the wave propagation velocity, length, height, surface condition and so on all change obviously, because of the influences caused by the factors such as the water depth, the topography, the bottom friction, the obstacle, current and so on. Because the shallow water area is the main area for humanity practices active, the wave change at the shallow water area has the greatest influences to marine environment, resources and engineering construction and so on.In the coastal engineering,wave deformation and wave-induced current has been an important topic in coastal dynamics. A comprehensive numerical model for wave deformation and wave breaking plays an important role not only in practical application but also intheoretical research.At the same time, because of the different wave reflection on different revetments, rationally defining wave reflection also play an important role in numerical simulation.This paper summarized various Boussinesq-type wave-breaking models and analyzed some problems related to the application to the wave-induced current. In this thesis, first a full nonlinear Boussinesq wave model is established to simulate wave deformation in coastal area, and several terms are added into governing equations to simulate the effect of bottom friction, wave breaking and subgrid turbulent mixing. A Predictor-Corrector finite difference scheme was employed to solve the extended equations numerically.In order to verify the accuracy and applicability of the model, several numerical results from the model are compared with available physical experiment data. Comparisons show that numerical results agreed well with experimental data. Simultaneously, this paper has also discussed the wave reflection considering the different revetments based on two-point method conbined with model experiment, and provied the rational parameters of boundary condition in numerical simulation, and therefore, accuracy of sumulation has been improved.更多还原