【摘要】：畸形波是一種具有大波高和強破壞性的波浪,由于其多次造成海上事故而受到人們關(guān)注。然而,由于畸形波出現(xiàn)的偶然性與短暫性,其實測數(shù)據(jù)有限,對于畸形波的研究目前仍不成熟�；尾ㄒ话阃蝗怀霈F(xiàn),沒有預(yù)兆,很難預(yù)測,存在時間較短,很快消失,可以產(chǎn)生于深水、淺水或有限水深區(qū)域,可以產(chǎn)生于風(fēng)暴中或一般天氣,可以產(chǎn)生于較強海流海域或無明顯海流海域。鑒于畸形波的特殊性及破壞性,研究畸形波的機理、模擬及其與結(jié)構(gòu)的相互作用具有重要的理論意義和工程實際意義。本文作為國家自然科學(xué)基金項目“畸形波的動力學(xué)機理及其對深海平臺強非線性作用研究”的重要組成部分,旨在在現(xiàn)有畸形波研究成果的基礎(chǔ)上,進(jìn)一步深入討論畸形波的動力學(xué)機理,有效模擬不同類型的畸形波,研究畸形波與結(jié)構(gòu)的相互作用,提出能夠有效模擬具有瞬態(tài)沖擊及復(fù)雜自由液面流動特點的畸形波與結(jié)構(gòu)流固耦合作用的方法。本文對現(xiàn)有畸形波動力學(xué)機理進(jìn)行討論,在現(xiàn)有研究的基礎(chǔ)上,提出了基于概率的波列疊加模型和基于呼吸子解的二階非線性解,采用數(shù)值波浪水槽模擬了不同類型的畸形波,并對其與結(jié)構(gòu)物(如圓柱和平板)的相互作用展開了深入研究。本文在研究過程中取得了豐碩的研究成果:在畸形波模擬模型、數(shù)值波浪水槽技術(shù)與畸形波上浪模型等方面對現(xiàn)有方法提出了有效的改進(jìn);在畸形波流固耦合計算方面提出了新的算法。論文的主要研究工作如下:(1)歸納總結(jié)了現(xiàn)有的畸形波動力學(xué)機理模型,畸形波模擬方法以及畸形波與結(jié)構(gòu)物相互作用的研究,分析了現(xiàn)有模型與方法的優(yōu)點與不足,闡述了有待補充和完善的研究內(nèi)容。(2)基于N-S方程與VOF方法,采用Visual Basic語言構(gòu)建二維數(shù)值波浪水槽。采用速度邊界賦值(速度入口)的方式有效模擬畸形波,同時保留畸形波的非線性。(3)從初始擾動反演角度討論了畸形波的聚焦模型,并討論了具有Gauss包絡(luò)形態(tài)的畸形波的演化特征。(4)傳統(tǒng)的動量源法和松弛法消波簡單方便,但消波系數(shù)為常數(shù),對變化流場的適應(yīng)性較弱,且有時對大規(guī)模質(zhì)量遷移問題的消波效果欠佳。鑒于以上不足之處,對傳統(tǒng)松弛法進(jìn)行改進(jìn),引入隨時間變化的消波系數(shù),提出了一種基于松弛法的守恒消波法。守恒消波法在消波區(qū)域設(shè)置質(zhì)量源匯,通過求解守恒方程動態(tài)確定消波系數(shù),適應(yīng)流場變化,在降低來波能量的基礎(chǔ)上,同時消除來波的多余質(zhì)量,減小消波區(qū)長度,提高計算效率。(5)傳統(tǒng)的波列疊加模型可以有效的模擬滿足定義的畸形波,因而在實驗室和數(shù)值水槽中有著廣泛的應(yīng)用。然而,采用傳統(tǒng)方法,能量比例與組成波數(shù)目等參數(shù)往往憑經(jīng)驗選取,當(dāng)匯聚波列能量比例較大時,與真實海況不符,比例較小時,模擬效率較低。鑒于以上不足之處,考慮到非規(guī)則波浪場的隨機性本質(zhì),本文在傳統(tǒng)方法的基礎(chǔ)上提出了一種基于概率的畸形波波列疊加模型。通過給出不同能量比例、不同組成波數(shù)目下的畸形波生成概率,實現(xiàn)合理高效地確定計算參數(shù),同時盡可能的降低匯聚波列能量比例,增加與實際海況的符合程度。(6)作為一種應(yīng)用廣泛的畸形波非線性動力學(xué)模型,三階Schr?dinger方程的Peregrine呼吸子解已經(jīng)在實驗室中成功模擬。本文在數(shù)值水槽中模擬Peregrine呼吸子解,給出畸形波生存期和傳播距離的表達(dá)式,并給出且成功模擬了有限水深下基于Peregrine呼吸子解的畸形波Stokes二階波。(7)利用數(shù)值波浪水槽研究了畸形波對剛性水平板的上浪現(xiàn)象,針對畸形波大波高和高能量的特點,考慮到畸形波在甲板上的繼續(xù)傳播以及潰壩延遲效應(yīng)等因素,改進(jìn)了傳統(tǒng)的潰壩模型Ritter解,提出了一種聯(lián)合波浪-潰壩模型。利用聯(lián)系波浪-潰壩模型,成功地預(yù)測了畸形波上浪的甲板上水深,以及甲板上水體的截面速度。(8)基于Gauss包絡(luò)形態(tài),求解了畸形波對垂直圓柱體的繞射問題,給出了圓柱所受的波浪力和波浪彎矩,以及流場遠(yuǎn)場解。采用勢流頻域求解器對上述繞射問題進(jìn)行數(shù)值求解,并與理論解進(jìn)行對比,驗證了理論公式的正確性。(9)畸形波與結(jié)構(gòu)的相互作用往往包括瞬態(tài)的強沖擊載荷,以及復(fù)雜的自由液面流動,如甲板上浪與砰擊現(xiàn)象。針對以上特點,受到勢流理論中附加阻尼概念的啟發(fā),本文提出了一種基于SIMPLE算法的整體隱式全耦合算法(SBMIM),用來模擬具有強附加質(zhì)量效應(yīng)以及復(fù)雜自由液面流動的流固耦合現(xiàn)象。利用SBMIM,成功模擬了畸形波彈性甲板上浪與砰擊的現(xiàn)象,并研究了結(jié)構(gòu)水彈性動力學(xué)響應(yīng),濕模態(tài),以及流場局部壓力等量。
[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.
【學(xué)位授予單位】：上海交通大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TV139.26

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本文編號：2125554