畸形波数值模拟及其对结构物的作用
发布时间：2018-07-15 22:16
【摘要】：畸形波是一种具有大波高和强破坏性的波浪,由于其多次造成海上事故而受到人们关注。然而,由于畸形波出现的偶然性与短暂性,其实测数据有限,对于畸形波的研究目前仍不成熟。畸形波一般突然出现,没有预兆,很难预测,存在时间较短,很快消失,可以产生于深水、浅水或有限水深区域,可以产生于风暴中或一般天气,可以产生于较强海流海域或无明显海流海域。鉴于畸形波的特殊性及破坏性,研究畸形波的机理、模拟及其与结构的相互作用具有重要的理论意义和工程实际意义。本文作为国家自然科学基金项目“畸形波的动力学机理及其对深海平台强非线性作用研究”的重要组成部分,旨在在现有畸形波研究成果的基础上,进一步深入讨论畸形波的动力学机理,有效模拟不同类型的畸形波,研究畸形波与结构的相互作用,提出能够有效模拟具有瞬态冲击及复杂自由液面流动特点的畸形波与结构流固耦合作用的方法。本文对现有畸形波动力学机理进行讨论,在现有研究的基础上,提出了基于概率的波列叠加模型和基于呼吸子解的二阶非线性解,采用数值波浪水槽模拟了不同类型的畸形波,并对其与结构物(如圆柱和平板)的相互作用展开了深入研究。本文在研究过程中取得了丰硕的研究成果:在畸形波模拟模型、数值波浪水槽技术与畸形波上浪模型等方面对现有方法提出了有效的改进;在畸形波流固耦合计算方面提出了新的算法。论文的主要研究工作如下:(1)归纳总结了现有的畸形波动力学机理模型,畸形波模拟方法以及畸形波与结构物相互作用的研究,分析了现有模型与方法的优点与不足,阐述了有待补充和完善的研究内容。(2)基于N-S方程与VOF方法,采用Visual Basic语言构建二维数值波浪水槽。采用速度边界赋值(速度入口)的方式有效模拟畸形波,同时保留畸形波的非线性。(3)从初始扰动反演角度讨论了畸形波的聚焦模型,并讨论了具有Gauss包络形态的畸形波的演化特征。(4)传统的动量源法和松弛法消波简单方便,但消波系数为常数,对变化流场的适应性较弱,且有时对大规模质量迁移问题的消波效果欠佳。鉴于以上不足之处,对传统松弛法进行改进,引入随时间变化的消波系数,提出了一种基于松弛法的守恒消波法。守恒消波法在消波区域设置质量源汇,通过求解守恒方程动态确定消波系数,适应流场变化,在降低来波能量的基础上,同时消除来波的多余质量,减小消波区长度,提高计算效率。(5)传统的波列叠加模型可以有效的模拟满足定义的畸形波,因而在实验室和数值水槽中有着广泛的应用。然而,采用传统方法,能量比例与组成波数目等参数往往凭经验选取,当汇聚波列能量比例较大时,与真实海况不符,比例较小时,模拟效率较低。鉴于以上不足之处,考虑到非规则波浪场的随机性本质,本文在传统方法的基础上提出了一种基于概率的畸形波波列叠加模型。通过给出不同能量比例、不同组成波数目下的畸形波生成概率,实现合理高效地确定计算参数,同时尽可能的降低汇聚波列能量比例,增加与实际海况的符合程度。(6)作为一种应用广泛的畸形波非线性动力学模型,三阶Schr?dinger方程的Peregrine呼吸子解已经在实验室中成功模拟。本文在数值水槽中模拟Peregrine呼吸子解,给出畸形波生存期和传播距离的表达式,并给出且成功模拟了有限水深下基于Peregrine呼吸子解的畸形波Stokes二阶波。(7)利用数值波浪水槽研究了畸形波对刚性水平板的上浪现象,针对畸形波大波高和高能量的特点,考虑到畸形波在甲板上的继续传播以及溃坝延迟效应等因素,改进了传统的溃坝模型Ritter解,提出了一种联合波浪-溃坝模型。利用联系波浪-溃坝模型,成功地预测了畸形波上浪的甲板上水深,以及甲板上水体的截面速度。(8)基于Gauss包络形态,求解了畸形波对垂直圆柱体的绕射问题,给出了圆柱所受的波浪力和波浪弯矩,以及流场远场解。采用势流频域求解器对上述绕射问题进行数值求解,并与理论解进行对比,验证了理论公式的正确性。(9)畸形波与结构的相互作用往往包括瞬态的强冲击载荷,以及复杂的自由液面流动,如甲板上浪与砰击现象。针对以上特点,受到势流理论中附加阻尼概念的启发,本文提出了一种基于SIMPLE算法的整体隐式全耦合算法(SBMIM),用来模拟具有强附加质量效应以及复杂自由液面流动的流固耦合现象。利用SBMIM,成功模拟了畸形波弹性甲板上浪与砰击的现象,并研究了结构水弹性动力学响应,湿模态,以及流场局部压力等量。
[Abstract]:Deformed wave is a wave with high wave height and strong destructive, which has been paid attention to by its many accidents at sea. However, due to the contingency and transience of the abnormal waves, the data of the deformed wave are limited and the research on the deformed waves is still immature. The abnormal waves are usually suddenly appeared, there is no omen, it is difficult to predict and exist time. It can be produced in deep water, shallow water or limited water deep area, which can be produced in storm or general weather, and can be produced in strong sea current or no obvious sea current. In view of the particularity and destructiveness of the deformed waves, it is of great theoretical significance to study the mechanism of the deformed waves and to simulate the interaction with the structures. As an important part of the National Natural Science Fund Project "the dynamic mechanism of abnormal wave and its strong nonlinear effect on the deep-sea platform", this paper aims to further discuss the dynamic mechanism of the deformed wave on the basis of the present research results of the deformed waves, and effectively simulate different types of deformed waves. The interaction between the deformed wave and the structure is investigated. The method to effectively simulate the interaction of the abnormal wave and the structure of the complex free surface flow is proposed. The dynamic mechanism of the existing deformed waves is discussed. On the basis of the existing research, the probability based wave column superposition model and the respiration are proposed. The two order nonlinear solutions of the subsolution are used to simulate different types of deformed waves by numerical wave flume, and the interaction of them with the structures (such as cylinders and plates) is deeply studied. In this paper, a lot of research results have been obtained: in the deformable wave simulation model, the numerical wave flume technology and the deformed wave wave model, and so on. In the face of existing methods, effective improvements have been put forward and new algorithms are proposed in the calculation of deformed wave and solid coupling. The main research work of this paper is as follows: (1) the existing dynamic mechanism model of deformed wave, the simulation method of deformed wave and the interaction of deformed wave with structure phase are summarized, and the advantages of the existing models and methods are analyzed. The research content to be supplemented and perfected is expounded. (2) based on the N-S equation and the VOF method, a two-dimensional numerical wave tank is constructed in Visual Basic language. The deformed wave is effectively simulated by the way of velocity boundary value (velocity entry), while the non linear of the deformed wave is retained. (3) the deformed wave is discussed from the initial perturbation inversion angle. Focusing model, and discussing the evolution characteristics of the deformed wave with Gauss envelope form. (4) the traditional momentum source method and relaxation method are simple and convenient, but the wave dissipation coefficient is constant, the adaptability of the changing flow field is weak, and the elimination result of the large-scale mass transfer problem is not good. In view of the above shortcomings, the traditional relaxation method is introduced. A conservation wave method based on relaxation method is proposed in this paper. A conservation wave method based on relaxation method is proposed. The conservation wave method sets the quality source and sink in the wave elimination region. By solving the conservation equation, the wave dissipation coefficient is determined, the flow field is adapted to the change of the flow field, and the excess mass of the wave is eliminated and the wave elimination length reduces on the basis of the reduction of the wave energy. (5) the traditional wave column superposition model can be effectively simulated to satisfy the defined anomaly wave, so it is widely used in the laboratory and numerical sink. However, the traditional method is used in the traditional method, the energy ratio and the composition wave number are often selected by experience. When the energy ratio of the converging wave column is large, it is not with the real sea condition. In view of the above shortcomings and considering the randomness of the irregular wave field, this paper presents a probability based deformable wave column superposition model on the basis of the traditional method, which is based on the traditional methods. To determine the calculation parameters and reduce the energy ratio of the aggregation wave train as much as possible and increase the degree of coincidence with the actual sea condition. (6) as a widely used malformed wave non linear dynamic model, the Peregrine breathing subsolution of the three order Schr? Dinger equation has been simulated in the laboratory. This paper simulates the Peregrine breathing in the numerical sink. The expression of the survival time and propagation distance of the deformed wave is given, and the two order wave of the deformed wave Stokes based on the Peregrine breathing subsolution in the finite water depth is successfully simulated. (7) the wave phenomenon of the deformed wave to the rigid horizontal plate is studied by the numerical wave flume, and the abnormal waves are considered for the characteristics of the large wave height and high energy of the distorted waves. The continuous propagation of the deck and the delay effect of the dam break have improved the Ritter solution of the traditional dam break model. A joint wave break dam model is proposed. Using the model of the wave break dam, the deck water depth of the deformed wave waves and the cross section velocity on the deck water are successfully predicted. (8) based on the Gauss envelope form, the solution is solved. The wave force and the wave bending moment and the far field solution of the cylinder are given. The numerical solution of the above diffraction problem is solved by the potential flow frequency domain solver. The validity of the theoretical formula is verified by comparison with the theoretical solution. (9) the interaction between the deformed wave and the structure often includes the transient state. Strong impact loads and complex free surface flows, such as deck surf and slamming, are inspired by the concept of additional damping in potential flow theory. In this paper, an integral implicit total coupling algorithm (SBMIM) based on SIMPLE algorithm is proposed to simulate strong additional mass effect and complex free surface flow. The phenomena of the wave and slamming on the elastic deck of the deformed wave are successfully simulated by SBMIM, and the hydrodynamic response, the wet mode and the local pressure of the flow field are studied.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TV139.26
本文编号：2125554
[Abstract]:Deformed wave is a wave with high wave height and strong destructive, which has been paid attention to by its many accidents at sea. However, due to the contingency and transience of the abnormal waves, the data of the deformed wave are limited and the research on the deformed waves is still immature. The abnormal waves are usually suddenly appeared, there is no omen, it is difficult to predict and exist time. It can be produced in deep water, shallow water or limited water deep area, which can be produced in storm or general weather, and can be produced in strong sea current or no obvious sea current. In view of the particularity and destructiveness of the deformed waves, it is of great theoretical significance to study the mechanism of the deformed waves and to simulate the interaction with the structures. As an important part of the National Natural Science Fund Project "the dynamic mechanism of abnormal wave and its strong nonlinear effect on the deep-sea platform", this paper aims to further discuss the dynamic mechanism of the deformed wave on the basis of the present research results of the deformed waves, and effectively simulate different types of deformed waves. The interaction between the deformed wave and the structure is investigated. The method to effectively simulate the interaction of the abnormal wave and the structure of the complex free surface flow is proposed. The dynamic mechanism of the existing deformed waves is discussed. On the basis of the existing research, the probability based wave column superposition model and the respiration are proposed. The two order nonlinear solutions of the subsolution are used to simulate different types of deformed waves by numerical wave flume, and the interaction of them with the structures (such as cylinders and plates) is deeply studied. In this paper, a lot of research results have been obtained: in the deformable wave simulation model, the numerical wave flume technology and the deformed wave wave model, and so on. In the face of existing methods, effective improvements have been put forward and new algorithms are proposed in the calculation of deformed wave and solid coupling. The main research work of this paper is as follows: (1) the existing dynamic mechanism model of deformed wave, the simulation method of deformed wave and the interaction of deformed wave with structure phase are summarized, and the advantages of the existing models and methods are analyzed. The research content to be supplemented and perfected is expounded. (2) based on the N-S equation and the VOF method, a two-dimensional numerical wave tank is constructed in Visual Basic language. The deformed wave is effectively simulated by the way of velocity boundary value (velocity entry), while the non linear of the deformed wave is retained. (3) the deformed wave is discussed from the initial perturbation inversion angle. Focusing model, and discussing the evolution characteristics of the deformed wave with Gauss envelope form. (4) the traditional momentum source method and relaxation method are simple and convenient, but the wave dissipation coefficient is constant, the adaptability of the changing flow field is weak, and the elimination result of the large-scale mass transfer problem is not good. In view of the above shortcomings, the traditional relaxation method is introduced. A conservation wave method based on relaxation method is proposed in this paper. A conservation wave method based on relaxation method is proposed. The conservation wave method sets the quality source and sink in the wave elimination region. By solving the conservation equation, the wave dissipation coefficient is determined, the flow field is adapted to the change of the flow field, and the excess mass of the wave is eliminated and the wave elimination length reduces on the basis of the reduction of the wave energy. (5) the traditional wave column superposition model can be effectively simulated to satisfy the defined anomaly wave, so it is widely used in the laboratory and numerical sink. However, the traditional method is used in the traditional method, the energy ratio and the composition wave number are often selected by experience. When the energy ratio of the converging wave column is large, it is not with the real sea condition. In view of the above shortcomings and considering the randomness of the irregular wave field, this paper presents a probability based deformable wave column superposition model on the basis of the traditional method, which is based on the traditional methods. To determine the calculation parameters and reduce the energy ratio of the aggregation wave train as much as possible and increase the degree of coincidence with the actual sea condition. (6) as a widely used malformed wave non linear dynamic model, the Peregrine breathing subsolution of the three order Schr? Dinger equation has been simulated in the laboratory. This paper simulates the Peregrine breathing in the numerical sink. The expression of the survival time and propagation distance of the deformed wave is given, and the two order wave of the deformed wave Stokes based on the Peregrine breathing subsolution in the finite water depth is successfully simulated. (7) the wave phenomenon of the deformed wave to the rigid horizontal plate is studied by the numerical wave flume, and the abnormal waves are considered for the characteristics of the large wave height and high energy of the distorted waves. The continuous propagation of the deck and the delay effect of the dam break have improved the Ritter solution of the traditional dam break model. A joint wave break dam model is proposed. Using the model of the wave break dam, the deck water depth of the deformed wave waves and the cross section velocity on the deck water are successfully predicted. (8) based on the Gauss envelope form, the solution is solved. The wave force and the wave bending moment and the far field solution of the cylinder are given. The numerical solution of the above diffraction problem is solved by the potential flow frequency domain solver. The validity of the theoretical formula is verified by comparison with the theoretical solution. (9) the interaction between the deformed wave and the structure often includes the transient state. Strong impact loads and complex free surface flows, such as deck surf and slamming, are inspired by the concept of additional damping in potential flow theory. In this paper, an integral implicit total coupling algorithm (SBMIM) based on SIMPLE algorithm is proposed to simulate strong additional mass effect and complex free surface flow. The phenomena of the wave and slamming on the elastic deck of the deformed wave are successfully simulated by SBMIM, and the hydrodynamic response, the wet mode and the local pressure of the flow field are studied.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TV139.26
【参考文献】
相关期刊论文 前2条
1 杨冠声,董艳秋,陈学闯;畸形波对圆柱作用力计算的波形改造法[J];港工技术;2003年01期
2 杨冠声,董艳秋,陈学闯;畸形波(freak wave)[J];海洋工程;2002年04期
相关硕士学位论文 前1条
1 金晶;基于部分单元参数Youngs法的棱形液舱晃荡载荷分析研究[D];上海交通大学;2012年
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