本文關(guān)鍵詞： 立管 波流聯(lián)合作用 數(shù)值水池 載荷響應(yīng) 流固耦合　出處：《江蘇科技大學》2015年碩士論文　論文類型：學位論文

【摘要】：隨著深海資源開發(fā)領(lǐng)域的不斷拓展,海洋立管等結(jié)構(gòu)物在波流等外載荷下的運動響應(yīng)問題越來越受到人們的關(guān)注。本文在較為全面地回顧和總結(jié)了國內(nèi)外數(shù)值水池和海洋立管載荷響應(yīng)研究方法和最新進展的基礎(chǔ)上,基于時域方法和粘流理論,以不可壓縮流體連續(xù)方程、N-S方程和結(jié)構(gòu)動力學方程為基本控制方程,借助商用軟件平臺Ansys Workbench14.5,構(gòu)建了粘性數(shù)值水池,針對海洋立管的載荷響應(yīng)問題開展了以下研究工作并得到了相應(yīng)結(jié)論:(1)基于商用軟件FLUENT 14.5,結(jié)合軟件自定義函數(shù)(UDF)功能,采用速度邊界造波法和阻尼消波技術(shù),通過VOF追蹤自由液面,建立了精度良好的二維和三維數(shù)值波浪、波流數(shù)值水池。分析了不同波流參數(shù)聯(lián)合作用下數(shù)值水池的波浪參數(shù)變化,得到了波流同向時,波長變長,波幅減小;波流相向時,波長變小,波幅增加的結(jié)論。(2)在完成數(shù)值水池構(gòu)造的基礎(chǔ)上,建立了剛性海洋立管模型,對其在波流共同作用下所受載荷進行了仿真模擬。通過表面壓力和水平的作用力的分析,發(fā)現(xiàn)立管在波流同向中受力增加,且水平作用力系數(shù)增大;波流相向時,立管表面壓力減小,水平作用力系數(shù)降低。(3)采用雙向耦合分離法思想,通過流固耦合模塊System Coupling將流域和結(jié)構(gòu)域計算數(shù)據(jù)交互傳遞,對長徑比為8的柔性立管在數(shù)值水池中的運動響應(yīng)進行了雙向流固耦合模擬。結(jié)果分析表明,相對單獨波浪場中,立管在波流數(shù)值水池中迎浪向振動平衡位置偏向水流方向,橫浪向振幅顯著增大,軸向振動變化不大。同時通過文獻對比和水平作用力系數(shù)的分析驗證了所用方法進行流固耦合模擬的可行性。(4)數(shù)值模擬了長徑比為103的柔性立管在數(shù)值水池中的運動響應(yīng)。模擬結(jié)果表明波流作用對大長徑比的作用效果更為顯著,迎浪向振動平衡位置較單獨波浪場中向水流方向偏移,橫浪向出現(xiàn)明顯往復振動。波流同向時,立管運動振幅增大,整體受力下移;波流相向時,振幅減小,整體受力上移。
[Abstract]:Along with the deep sea resources development domain unceasing expansion. More and more attention has been paid to the motion response of marine risers and other structures under external loads such as waves and currents. In this paper, the research methods of load response of numerical pools and risers at home and abroad are reviewed and summarized. On the basis of new developments. Based on the time-domain method and the viscous flow theory, the incompressible fluid continuity equations (N-S) and structural dynamics equations are taken as the basic governing equations. With the help of the commercial software platform Ansys Workbench 14.5, the viscous numerical water pool is constructed. The following research work has been done on the load response of marine riser and the corresponding conclusion: 1) based on the commercial software FLUENT 14.5and combined with the function of software custom function. Two and three dimensional numerical waves with good accuracy are established by means of velocity boundary method and damped wave elimination technique. The free liquid surface is tracked by VOF. The variation of wave parameters under the combined action of different wave and current parameters is analyzed, and the wave length and amplitude are obtained when the wave and current are in the same direction. The conclusion that the wave length becomes smaller and the wave amplitude increases when the wave current is in the opposite direction. (2) on the basis of completing the construction of the numerical pool, the rigid ocean riser model is established. Through the analysis of surface pressure and horizontal force, it is found that the force of riser increases in the same direction of wave and current, and the coefficient of horizontal force increases. When the wave and current are opposite, the surface pressure of riser decreases and the coefficient of horizontal force decreases. 3) the bidirectional coupling separation method is adopted. The fluid-solid coupling module (System Coupling) is used to transfer the data between the basin and the domain. The motion response of flexible riser with aspect ratio of 8 in a numerical pool is simulated by two-way fluid-solid coupling. The results show that the response of the flexible riser in a single wave field is higher than that in a single wave field. The balance position of the riser in the wave-current numerical pool is inclined to the direction of the flow, and the amplitude of the transverse wave increases significantly. The axial vibration has little change, and the feasibility of fluid-solid coupling simulation is verified by the comparison of literature and the analysis of horizontal force coefficient. The motion response of flexible riser with a aspect ratio of 103 is numerically simulated in a numerical pool. The simulation results show that the effect of wave-current action on large aspect ratio is more significant. The equilibrium position of facing wave direction vibration is more than that of single wave field, and the transverse wave direction appears reciprocating vibration obviously. When the wave current is in the same direction, the amplitude of riser motion increases and the whole force moves downward. When the wave and current are opposite, the amplitude decreases and the whole force moves up.
【學位授予單位】：江蘇科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P75

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相關(guān)碩士學位論文 前1條

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本文編號：1466253