應用主動縱搖船艏振動翼輔助船舶於不規則波中推進之研究

本研究提出的應用主動縱搖船艏振動翼為一種新型的節能裝置，可以有效地擷取波浪中的能量，並將其轉換為可用之推力以輔助一般商船推進，如此將大幅減少船舶燃油消耗，達到降低二氧化碳排放量的目標。首先使用一艘貨櫃輪的1/50縮尺船模進行自航船模實驗，並選用翼型為NACA0016之振動翼兩片分別安裝於船艏左右兩舷，進行一系列迎波實驗以驗證該裝置的可行性。規則波實驗結果顯示，只要振動翼的縱搖領先起伏相位角在適當範圍內，對於船舶於波浪中推進之速度提升與節能效益可有顯著成果，當波長船長比為1.0和1.3時，最大能源節省分別可達6.2%和18.9%。而不規則波實驗由於受限於波浪無法預知以及設備響應速度不足等因素，艏翼縱搖領先起伏相位角最高只能到56度，平均船速增加之百分比也僅提升1.03%。但根據整體趨勢判斷，若能克服實驗設備的限制提升艏翼響應速度，預期將能使船速更顯著地提升。接著透過計算流體動力分析軟體FLUENT探究振動翼推進性能受波浪環境之影響，在波浪領先船艏起伏相位角為條件下所擷取的波浪能量顯著地超越波阻的損耗，使得在特定艏翼縱搖領先起伏相位角範圍內之推力係數明顯提升。然而若振動翼在起伏的過程中有露出水面，則艏翼的最佳領先相位角將會需要增加，而此現象並不利於不規則波環境下之艏翼控制，因此因應不規則波環境，艏翼設置位置應盡量增加深度以確保翼型起伏時皆完整沒在水面下。本研究更進一步找出振動翼之史特豪數(St)與最佳入流攻角之間的關係，藉此開發出不規則波之改良控制法則，改良後不只平均推力係數提升1.93%，且總效率及艏翼縱搖效率亦分別提升4.29%及7.39%。本研究所得之艏翼改良控制法則可做為後續進行不規則波實驗驗證的參照依據，預期將能進一步有效提升不規則波中的推力及整體推進效率。

關鍵字

船艏振動翼；波浪推進；自航船模實驗；計算流體力學

並列摘要

The active pitch oscillating bow fin proposed in this research is a new idea of energy-saving device for ship propulsion by effectively extracting wave energy to convert into available propulsion force. The purpose of this research is to substantially reduce fuel consumption as well as carbon dioxide emissions with the aid of the device installed in merchant ships. First of all, free-running model tests were conducted by using a scale model of a container ship, with two pitch-oscillating bow fins in NACA0016 section mounted on the bow of port and starboard. A series of test were conducted in head waves to verify the validity of the device. The results of the regular wave tests reveal considerable enhancement of speed and energy-saving efficiency when the phase lead of the bow fin pitch motion with respect to its heave motion is set in a proper range. For the cases of wavelength to ship length ratio of 1.0 and 1.3, the maximum of power efficiency improving may reach to around 6.5% and 18.9% respectively. Nevertheless, the tests of irregular waves are subject to unpredicatability of waves and unsufficient response speed of the actuator. It means that the phase lead of the bow fin pitch motion with respect to its heave motion is limited to 56 degree at most. Consequently, the mean speed of ship improved merely 1.03.%. Based on the trend of test results in irregular waves, it can be expected that the speed should increase as long as the actuator can response faster. Then the CFD software FLUENT was applied to investigate the influence of waves to efficiency of the pitch-oscillating bow fins. According to the CFD results, for the case that the phase lead of the heaving motion with respect to the incident wave is set at 120 degree, the thrust obtained from wave energy extraction become significantly higher than the added resistance due to wave, and makes the thrust coefficient significantly increased in a proper range of the phase lead of the bow fin pitch motion with respect to its heave. However, if the pitch-oscillating bow fins moving out of water surface occurred, the optimal phase lead of the bow fin pitch motion with respect to its heave will increase. This is not good for the bow fins control in irregular waves. Therefore, it is important to mount the pitch-oscillating bow fins as deep as possible. Furthermore, this research intends to ascertain the relationship between optimum angle-of-attack and Strouhal number(St), so as to develop a method for improving the bow fins control in irregular waves. By applying the present modified method, not only the average thrust coefficient is improved by 1.93%, but the total efficiency and pitching efficiency also increases by 4.29% and 7.39% respectively. As a future work, it is suggested to carry out irregular wave tests applying the modified control method of pitch-oscillating bow fins for verifying its validity to enhance the performance of the bow fins in irregular waves.

並列關鍵字

active pitch-oscillating bow fin ； wave propulsion ； free-running model test ； Computational Fluid Dynamics (CFD)

參考文獻

[26] 林昱仲,“自航船模實驗系統建立及其應用之研究,”, 台灣大學工程科學及海

[3] C.C. Lindsey, “Form, function and locomotory habits in fish,” in Fish Physiology Vol. VII Locomotion, W. S. Hoar and D. J. Randall, Eds. New York: Academic, pp. 1–100, 1978

[4] Michael Sfakiotakis et al , “Review of Fish Swimming Modes for Aquatic Locomotion,” IEEE JOURNAL OF OCEANIC ENGINEERING, vol. 24, NO. 2, APRIL 1999

[5] W.J. McCroskey, “Unsteady hydrofoils, Annu,” Rev. Fluid Mech., 14, 285-311, 1982

[6] P. Freymuth, “Propulsive vortical signature of plunging and pitching hydrofoils,” AIAA J., 26, 881-883, 1988

國際替代計量

應用主動縱搖船艏振動翼輔助船舶於不規則波中推進之研究

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