本文選題：水下溢油 + 數(shù)值模擬　； 參考：《大連理工大學(xué)》2015年碩士論文

【摘要】：由于全球?qū)κ湍茉葱枨罅恐鹑者f增和海上勘探、開采規(guī)模不斷擴(kuò)大,海上溢油事故,包括油輪傾覆、海底井噴、輸油管道滲漏等屢見不鮮,對海洋生態(tài)環(huán)境的影響是惡劣且難以消除的。在溢油事故的預(yù)測和應(yīng)急處理研究過程中,除衛(wèi)星、雷達(dá)以及微波等遙感技術(shù)的監(jiān)測預(yù)報(bào)以外,計(jì)算機(jī)模擬以其強(qiáng)大的數(shù)據(jù)處理能力,對相關(guān)因素的綜合考慮,在溢油事故應(yīng)急行動(dòng)中發(fā)揮著日益重要的作用。在溢油事故的預(yù)測和應(yīng)急處理研究中,以往注意力多集中在海底管道破壞或油田的井噴造成的大量溢油的情況。本文重點(diǎn)關(guān)注海底管道出現(xiàn)破裂等問題而產(chǎn)生蠕孔溢油的水下運(yùn)動(dòng)軌跡和影響范圍。此類溢油由于其隱蔽性和長期性也會(huì)造成較嚴(yán)重的后果。本文基于CFD通用軟件FLUENT,采用標(biāo)準(zhǔn)k-ε紊流模型,基于壓力的求解器(Pressure-Based Solver)和壓力速度耦合的PISO算法,采用VOF追蹤相界面,考慮了純流和純波作用,建立了二維的海底管線微孔溢油數(shù)值模型。在純橫向水流環(huán)境下,給出溢油水下運(yùn)動(dòng)軌跡數(shù)值結(jié)果,和前人實(shí)驗(yàn)值吻合較好。引入無量綱密度弗勞德數(shù)Fr0和溢油出口速率與流體流動(dòng)速率的比值R0來探討影響溢油輸運(yùn)過程的因素。比較了Fr0和R0值不同時(shí),溢油初期上升的高度,產(chǎn)生的渦旋,溢油軌跡的彎曲,油體水下漂移距離,浮上水面的位置和時(shí)間等變化情況。由分析知當(dāng)溢油流速和周圍水流流速相差不大,油品較重時(shí),溢油上浮到海面時(shí)間更長,污染范圍更廣,尋找、封堵溢油口和清理油污的工作量及難度加大。在純波浪環(huán)境下,模擬了不同波陡kA的波浪環(huán)境和靜水環(huán)境溢油的水下運(yùn)動(dòng)形態(tài)、流場和水面輸運(yùn)情況。發(fā)現(xiàn)靜水中溢油在靠近水面前油柱幾乎垂直上升,到達(dá)水面附近油前端才略有擺動(dòng),同時(shí)隨溢油上浮有對稱渦旋現(xiàn)象。油在水面關(guān)于溢油口對稱輸運(yùn)。而波浪環(huán)境中溢油軌跡從開始的垂直上浮很快變?yōu)槌蔛型擺動(dòng)上升,且隨油運(yùn)動(dòng)產(chǎn)生的渦旋場更加復(fù)雜,溢油在水面的輸運(yùn)也不再關(guān)于溢油口對稱。波陡kA越大,溢油柱越早受到擾動(dòng),軌跡擺動(dòng)幅度越大,對稱渦旋情形越難維持。引入溢油在水面輸運(yùn)影響范圍的概念和指標(biāo)f來表征不同波陡kA對溢油水面輸運(yùn)相對于溢油口的非對稱性的影響,數(shù)據(jù)分析后表明波陡kA越大,波浪非線性越強(qiáng),溢油的影響范圍越向右偏移,即溢油順波方向的輸運(yùn)越強(qiáng)。
[Abstract]:As the global demand for oil energy increases day by day and offshore exploration, the scale of exploitation continues to expand, the oil spill accidents on the sea, including oil tanker overturning, seabed blowout, and oil pipeline leakage are common, and the impact on the marine environment is bad and difficult to eliminate. In the process of prediction and emergency treatment of oil spill accidents, the satellite, Besides the monitoring and forecasting of remote sensing technology such as radar and microwave, computer simulation plays an increasingly important role in the emergency action of oil spill accident, with its powerful data processing ability and comprehensive consideration of related factors. In the study of oil spill accident prediction and emergency treatment, attention has been focused on submarine pipeline destruction or oil field. A lot of oil spill caused by blowout. This article focuses on the underwater trajectory and influence range of the creeping oil spills. This kind of oil spill will result in serious consequences due to its concealment and long term. Based on the CFD general software FLUENT, the standard k- e turbulence model is used, based on the pressure. The Solver (Pressure-Based Solver) and the pressure velocity coupling PISO algorithm, using the VOF tracking phase interface and considering the pure current and pure wave action, have established a two-dimensional numerical model of the microporous oil spillage in the submarine pipeline. In the pure transverse flow environment, the results of the number of underwater moving trajectories of the spilled oil are given, which is in good agreement with the previous experimental values. The density Froude number Fr0 and the ratio of the flow rate of the spilled oil to the fluid flow rate R0 are used to discuss the factors affecting the transport process of the oil spilled oil. Compared with the difference between the Fr0 and R0 values, the height of the initial rising of the oil spill, the generated vortex, the curve of the oil spill path, the drift distance of the oil body, the position and time of the floating surface and so on. There is little difference between the flow velocity of the oil spilled and the flow velocity in the surrounding water. When the oil is heavier, the oil spill is floating to the sea for a longer time, and the pollution range is wider. The work and difficulty of blocking the oil spill and cleaning the oil are more difficult. In the pure wave environment, the wave environment of different wave steep kA and the underwater movement form of the oil spill in the hydrostatic environment, the flow field and the water surface are simulated. It is found that the oil spillage in the hydrostatic water almost vertically rises before the oil column near the water surface, and the oil front-end near the surface of the water is slightly swinging, while the oil spill has symmetrical vortices. The vortex field produced by motion is more complex, and the transport of oil spill on the surface of the water is no longer symmetrical. The larger the kA is, the earlier the oil spilled column is disturbed, the greater the swing amplitude is, the more difficult the symmetry vortex is to be maintained. The concept of the influence range of the oil spill in the water surface and the reference standard f to characterize the transport of the different wave steepness kA to the oil spilled water surface With the influence of the asymmetry of the oil spill, the data analysis shows that the greater the wave steepness kA is, the stronger the wave nonlinearity is, the more the influence range of the spilled oil moves to the right, that is, the better the transport of the spilled oil is in the direction of the wave.

【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X55

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 楊小慶，沈洪道，汪德勝;油在河流中傳輸?shù)碾p層數(shù)學(xué)模型[J];水利學(xué)報(bào);1996年08期

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本文編號：1844307