- 學位論文
浮游式黑潮發電渦輪機之流體動力性能實驗研究
Experimental Study on the Hydrodynamic Performance of a Floating Kuroshio Current Turbine
摘要
本研究建立一浮游式黑潮發電渦輪機實驗系統，包含黑潮發電機模型及流體動力量測系統，並在拖曳水槽中完成浮游式黑潮發電渦輪機單獨葉輪之流體動力性能實驗、葉輪誘導速度量測實驗及整組發電機之性能實驗。 本研究完成單獨葉輪的流體動力性能量測，並將量測結果與雷諾時均法(RANS)計算結果做比較，比較結果顯示在三個流速下，葉輪之功率係數與扭力係數的實驗結果與計算值吻合，此葉輪的最高功率係數約為0.45，發生在TSR 5 左右，而軸向力係數之量測結果高於計算值。 為驗證軸向力係數的量測結果，本研究使用都卜勒速度紀錄儀量測葉輪後方的流速，並同時用單獨葉輪之量測系統來量測流體動力性質，以拖車速度及都卜勒速度紀錄儀量測的流速計算軸向誘導係數(Axial Induction Factor)，誘導係數小於0.5時用軸向動量理論計算推力係數，誘導係數大於0.5時以Buhl’s經驗公式計算推力係數，將軸向誘導係數計算的推力係數與單獨葉輪量測系統量測的軸力係數做比較，發現兩者的推力係數值接近。由比較結果得知本研究設計之流體動力量測系統所量測之軸力係數具有可靠性，並得知此葉輪的軸向力係數與周速比曲線：軸向力係數在TSR4~8時大部分介於0.8~1.0之間。
並列摘要
A Floating Kuroshio Turbine (FKT) hydrodynamic performance measurement system, which includes the model and measuring system, was setup to study the hydrodynamic performance of a designed Floating Kuroshio Turbine. The hydrodynamic performance of the blade, the induced velocity of the blade and the hydrodynamic performance of the whole current turbine were measured in the towing tank. The hydrodynamic performance of the blade tested results were compared with the results calculated by Reynolds-Averaging Naiver-Stokes Equations (RANS) solver. The measured power coefficient and torque coefficient agreed well with the calculated results. The maximum power coefficient of this turbine is about 0.45 which occurred at TSR 5. However, the measured lift coefficient is higher than the calculated results. In order to verify the measured results of the lift coefficient, the induced velocity of the blade was measured by the Doppler Velocity Log (DVL), and the hydrodynamic performance of the blade was also measured at the same time. The axial induction factor was calculated by the velocity of the towing carriage and the measured velocity from DVL. The lift coefficient was calculated from axial momentum theory when the axial induction factor is smaller than 0.5, and the lift coefficients was calculated by Buhl’s empirical formula when axial induction factor is larger than 0.5. The lift coefficient calculated by induction factor agrees well with the measured lift coefficient. The test results show that the lift coefficient measured by the hydrodynamic measurement system is reliable. It also shows that the value of the lift coefficient is between 0.8 and 1.0 when the TSR is between 4 and 8.