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| 題 名 | 非線性波作用下離岸風機基樁之溯升高度和波浪荷載模擬=The Simulation of Run-Up Heights and Wave Loads of Offshore Wind Turbines Induced by Nonlinear Waves |
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| 作 者 | 陳靖夫; 林宇銜; | 書刊名 | 中國造船暨輪機工程學刊 |
| 卷 期 | 34:4 2015.11[民104.11] |
| 頁 次 | 頁197-206 |
| 分類號 | 448.165 |
| 關鍵詞 | 計算流體力學; 離岸風力發電機基樁; 溯升; 波浪荷載; 體積分率法; CFD; Offshore wind turbines; Run-up; Volume of fraction; |
| 語 文 | 中文(Chinese) |
| 中文摘要 | 本本研究主要以計計算流體力學(computationaal fluid dynammics, CFD) 軟體體,並以 RANSS方程式搭配 kk-ε紊流模式作作為求解器,模模擬風機基樁在在不同波浪條條件下之溯升與與波浪荷載情形形。在自由液面面的設定上,則是使用體積積分率(volume of fraction, VVOF)方法處理理自由液面問題題。爾後,再以以此方法模擬單單樁式、三腳管式以及重力力式三種不同單單一風機基樁型型式,在不同同波浪條件影響響下的波浪荷載載情形與溯升高高度變化。經模擬分析後發發現,在波浪尖尖銳度較高、週週期較短的波波浪環境下,三三種不同種類的的基樁皆有較高高的溯升高度,但基樁所受受到的波力卻較較小;反之,波浪尖銳度較較小、週期較長長的波浪條件下下,雖然溯升升高度較小,但波力卻會對對基樁造成較大大的波浪荷載。最後,本文文以史托克斯二二階理論為基礎礎,並以速度停停滯頭理論作為波浪溯升半半經驗公式之參參考依據,探討討溯升校正因因子在不同基樁樁形式及波浪條條件下之變化情情形。結果指出,溯升校正正因子會隨著波波浪尖銳度及最最大溯升高度度的增加而有減減少的趨勢。 |
| 英文摘要 | A hydrodynamic simulation of wave run-up heights and wave loads on three types of wind turbine foundations, i.e. monopile, gravity-based and tripod support structures, was conducted using a RANS solver for incompressible fluid flows, employing k-ε turbulent closure. The present CFD model based on the commercial software, FLUENT, is provided to calculate the maximum wave heights and wave loads that the foundations may experience during the wave propagation in Stokes second order wave theory. The wave run-up on different designs of wind turbine foundations is discussed by the breakwater effect, which would be the dominant factor deciding the minimum air-gap requirement of working platform. Thus, a series of numerical experiments with different cases of wave steepness ka as well as scattering parameter kA were conducted by comparing the effects of wave characteristics on these support structures. Due to the contribution of the present CFD model, a semi-empirical formula is calibrated based on velocity stagnation head theory for crest kinematics. It is obvious that the increased velocities close to the cylinder is the predominant factor of run-up heights, in which the velocity head is included. Eventually, the results indicate that the difference among the maximum normalized run-up heights of these support structures is smaller for lower wave steepness than those for high wave steepness. In contrast, it is shown that the difference among the wave loads of these foundations is larger for lower wave steepness than those for higher wave steepness. A modified run-up parameter is also obtained by means of numerical simulation and found that the decreased value of modified run-up parameter is accompanied with increased values of wave steepness and the maximum normalized run-up height. |
本系統中英文摘要資訊取自各篇刊載內容。