本文選題：港灣振蕩 + Boussinesq模型�。� 參考：《大連理工大學(xué)》2015年博士論文

【摘要】：港灣振蕩是一個在海岸工程領(lǐng)域中較為傳統(tǒng)且極其重要的研究方向。國內(nèi)外很多港口都觀測到了明顯的港灣振蕩現(xiàn)象,顯著地影響了港口的高效運行和港內(nèi)船舶的系泊安全。本文首先介紹了港灣振蕩的研究背景和意義,列舉了文獻中所反映出來的實際港口中發(fā)生的港灣振蕩事件,總結(jié)了這些港灣振蕩的特征,并系統(tǒng)地闡述了前人關(guān)于港灣振蕩的研究內(nèi)容。然后,介紹了本文采用的數(shù)值模型-FUNWAVE2.0,該模型是基于一組完全非線性Boussinesq方程建立的。文中介紹了數(shù)值模型的控制方程、數(shù)值離散、邊界條件以及域內(nèi)造波理論。隨后,通過模擬文獻中呈現(xiàn)的物理模型實驗,對數(shù)值模型用于模擬港灣振蕩現(xiàn)象的能力進行了驗證。本文在此基礎(chǔ)上進行了以下進一步的研究：Sobey (Sobey,2006. Normal mode decomposition for identification of storm tide and tsunami hazard. Coastal Engineering 53,289-301)在其論文中提出了用于計算港口共振頻率、共振模態(tài)形狀和分解由風(fēng)暴潮和海嘯誘發(fā)的港灣振蕩各模態(tài)成分響應(yīng)幅值的正交模態(tài)分解法。作者發(fā)現(xiàn),Sobey提出的正交模態(tài)分解法在數(shù)值處理全反射邊界條件的過程中存在不足,這將會導(dǎo)致正交模態(tài)分解法計算得到不精確的港口共振頻率和共振模態(tài)形狀。本文提出鏡像方法,對其全反射邊界條件的數(shù)值處理過程進行改進,并使用三個數(shù)值算例對改進的正交模態(tài)分解法進行了驗證。雖然正交模態(tài)分解法用于計算風(fēng)暴潮和海嘯誘發(fā)的港灣振蕩各模態(tài)響應(yīng)幅值是以線性理論為基礎(chǔ)的,本文使用兩組數(shù)值驗證算例對該方法用于分離港內(nèi)在弱非線性波況下各共振模態(tài)響應(yīng)幅值的適用性進行了研究。使用正交模態(tài)分解法,分離了由孤立波誘發(fā)的狹長型矩形港內(nèi)港灣振蕩各模態(tài)的響應(yīng)幅值,并系統(tǒng)地研究了不同的入射孤立波波高和不同的港口底坡對港內(nèi)相對波能分布的影響。研究表明：當入射孤立波波高較小時,港內(nèi)的共振波能主要集中在最低的幾個共振模態(tài),高模態(tài)僅占有很小的一部分能量；當入射孤立波波高增大時,港內(nèi)波能在不同共振模態(tài)上的分布趨向于均勻,高模態(tài)占有的波能比例增加。在本文給出的入射孤立波波高和港口底坡的變化范圍內(nèi),對于相同的入射孤立波波高,港口底坡的變化對于港內(nèi)相對波能在各模態(tài)上的分布影響很小。采用完全非線性Boussinesq模型,模擬了雙色波群引起的狹長型矩形港灣內(nèi)的共振現(xiàn)象。文中提出了一個基于最小二乘法的波浪分離程序,將港內(nèi)的低頻波浪成分進一步分解為鎖相長波和自由長波。進而研究了港灣處于第一共振模態(tài)下鎖相長波和自由長波的波幅以及它們相對成分隨著短波波長的變化。為了進行對比,也考慮了波群未能誘發(fā)港灣發(fā)生共振的情況。研究表明：無論港內(nèi)是否發(fā)生共振,鎖相長波和自由長波的波幅以及它們相對成分均與短波波長密切相關(guān)。針對本文中所研究的港口和短波頻率的變化范圍,當港內(nèi)發(fā)生最低模態(tài)的共振時,鎖相長波波幅總是要小于自由長波波幅,但是當平均短波波長大于0.66倍的港口長度時,前者往往要大于后者的一半；當港內(nèi)未發(fā)生共振且平均短波波長大于0.56倍港口長度時,鎖相長波波幅往往要大于自由長波波幅。
[Abstract]:The harbor oscillation is a more traditional and most important research direction in the field of coastal engineering. Many ports both at home and abroad have observed the obvious harbor oscillation phenomenon, which greatly influenced the efficient operation of the port and the safety of the mooring of the ships in the port. The harbor Oscillation events in the actual port are reflected, the characteristics of these harbors are summarized, and the previous studies on the harbor oscillation are systematically expounded. Then, the numerical model -FUNWAVE2.0 is introduced in this paper. The model is based on a set of complete non linear Boussinesq equations. The number of the models is introduced. The control equations of the value model, numerical dispersion, boundary conditions and the theory of intra domain wave making. Then, through the physical model experiments in the simulated literature, the ability of the numerical model to simulate the harbor oscillation is verified. On this basis, the following further studies are carried out: Sobey (Sobey, 2006. Normal mode decomposit) Ion for identification of storm tide and tsunami hazard. Coastal Engineering 53289-301) in his paper the orthogonal mode decomposition method for calculating the resonance frequency of the port, the shape of the resonant mode, and the decomposition of the response amplitude of the modal components of the Bay oscillation induced by storm tide and tsunami. The modal decomposition method has shortcomings in the process of dealing with the fully reflected boundary conditions. This will lead to the calculation of the inaccurate resonance frequency and resonant mode shape of the port by the orthogonal modal decomposition method. In this paper, a mirror image method is proposed to improve the numerical treatment process of its total reflection boundary condition, and three numerical examples are used to improve the numerical process. The orthogonal modal decomposition method is verified. Although the amplitude of the response modes of the Bay oscillation induced by the storm tide and the tsunami is based on the linear theory, the applicability of the method is used to separate the resonant modal response amplitude of the weakly nonlinear wave conditions in the port by two sets of numerical examples. An orthogonal modal decomposition method is used to separate the response amplitudes of each mode in a narrow rectangular harbor induced by a solitary wave. The effects of different incident solitary wave heights and different port slopes on the relative wave energy distribution in the port are systematically studied. The resonant wave energy is mainly concentrated in the lowest resonant modes, and the high mode only occupies a small part of the energy. When the incident solitary wave is high, the distribution of the internal wave energy in the different resonant modes tends to be uniform and the proportion of the wave energy in the high mode increases. The incident solitary wave height in this paper and the change of the bottom slope of the port are changed in this paper. For the same incident solitary wave, the change in the bottom slope of the port has little influence on the distribution of the relative wave energy in the port. The full nonlinear Boussinesq model is used to simulate the resonance phenomenon in the narrow rectangular harbor caused by the double color wave group. A wave separation process based on the least square method is proposed in this paper. In order, the low-frequency wave components in the port are further decomposed into phase-locked long wave and free long wave. Then the amplitude of the long wave and the free long wave in the first resonant mode of the harbor and the variation of their relative components along with the short wave wavelengths are studied. It is shown that the amplitude of the phase locked long wave and the free long wave and their relative components are closely related to the wavelength of the short wave regardless of whether there is resonance in the port. When the length of the port with short wave length is greater than 0.66 times the length of the port, the former is often more than half of the latter, and the length of the lock is often greater than the free long wave amplitude when there is no resonance in the port and the length of the mean short wave length is greater than 0.56 times the length of the port.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：U652.3
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本文編號：2009446