浮游式黑潮發電機拖曳流體動力性能實驗研究

本研究設計建造20KW浮游式黑潮發電機1/5比例模型，在機艙內部裝設有額定轉速為150RPM的永磁同步直驅發電機、扭矩計及轉速計。此黑潮發電機採下風式對轉雙葉輪，以平衡葉輪的旋轉力矩。試驗在拖曳槽中以728、364、242和182歐姆四個不同發電機負載下進行量測旋轉轉速、扭矩和推力。在試驗中由拖車以纜繩拖曳浮游式黑潮發電機機組，使用張力計測量繩的張力，角度計測量浮游式黑潮發電機的俯仰角和橫搖角。由測量數據計算浮游式黑潮發電機功率係數、扭矩係數、推力係數和總效率，量測的功率係數和扭矩係數與計算結果一致。此外亦進行在異常操作條件下即其中一個轉子被鎖定而另一個轉子在運行的性能，實驗結果顯示，當轉子被鎖定時，浮游式黑潮發電機因轉子侧向力的不平衡而產生平擺角，導致性能下降，扭矩係數和功率係數下降。在異常情況下，與正常運行條件下的性能曲線相比，性能曲線向左移動約一單位的葉尖周速比。實驗結果還顯示，在異常工作條件下浮游式黑潮渦輪發電機的俯仰和橫搖的變化是不顯著的。此外亦進行在波浪操作條件下的實驗，實驗結果顯示，機組隨著浪況不同，進行不同頻率振幅的周期運動，波浪操作條件下浮游式黑潮渦輪發電機的性能變化是不顯著的。

關鍵字

浮游式黑潮發電機；拖曳水槽；流體動力性能；波浪；洋流

並列摘要

A test apparatus, including a 1/5 scale model of the proposed 20 kW floating current turbine with a direct drive permanent magnet generator, a torque meter and a tachometer inside the nacelle. The downwind contra rotating rotors model were adopted to balance the torques generated by rotors. The test was conducted in a towing tank with four loads of 728, 364, 242, and 182 ohms. In the test, a rope was towed by a trailer, the tension force of the towing rope was measured using a tension meter. The pitch and roll angles of the floating current turbine were measured using angle meters. The power coefficient, torque coefficient, thrust coefficient and total efficiency were calculated from the measured data. The measured power coefficient and torque coefficient agreed with the calculated results. Moreover, the tests of abnormal operation conditions, where one of the rotors was locked and the other rotor was running, were also conducted. The experimental results indicated when a rotor was locked, the Kuroshio Current generator produced a yaw angle due to an imbalance of rotor forces, which caused a decrease in performance. The torque coefficient and power coefficient decreased. Under the abnormal condition, the performances curves shift left with a tip speed ratio of approximately 1 when compared with the performance curves under the normal operating condition. The experimental results also indicated that the change in the pitch and roll of the Kuroshio Current generator under the abnormal operating condition were non-significant. In addition, the experiments of the current turbine under different surface waves were also conducted. The experimental results show that the Kuroshio Current generator produced a periodic motion with different frequency and different amplitude depending on different surface waves. The experimental results also indicated that the performance change of the Kuroshio Current generator under the wave conditions were non-significant.