本論文主要是提出一套應用滾珠螺桿於波浪發電系統並探討其可行性。採用滾珠螺桿的原因是能利用其高達90%以上的正逆轉換效率[30]，將慢速的線性運動轉換成較快速的旋轉運動，對於波浪中浮體緩慢的起伏運動是有助益的，且搭配合適的螺桿導程以及轉盤直徑，將可再多擷取其轉動之動能而用之於發電效能之提升。
　　在數值計算方面，本文運用三維脈動型源點配合小板法求解該浮體於不同頻率領域下之各項流體係數，再利用四階Runge-Kutta法求出該浮體於時程領域下之運動量。本研究共模擬『浮桶』、『浮桶推動螺桿組』、『浮桶推動螺桿組並帶動發電機』三種型式之垂直運動量，並將數值模擬與實驗結果兩相比較；而後，可根據波浪通過浮桶時『浮桶推動螺桿組』的螺桿運動量計算結果，推測螺桿組裡的轉盤所產生的轉矩與轉速，進而預估由此轉矩與轉速帶動發電機後所能產生之電能。
另外，實驗時發現在單一波高下，『浮桶推動螺桿組』的垂直運動量會隨著周期的增加而變大，其運動與只有『浮桶』時大相逕庭，推測螺桿組與浮桶間由於機械系統阻尼而有一時間延遲，此時間延遲的長短又與螺桿的導程有關，為克服此不同步的問題，需要尖銳度(H⁄λ)較小的波浪，而對於本機構來說，導程角越小則偏向較費力機構，反之則亦然。
　　然而，螺桿式系統應用於波浪發電的設計，因加工、組裝的精度影響在元件與浮體運動之調和性有相當大之落差，因此，未來將繼續著重於完成螺桿式波浪發電系統之改良規劃設計與雛型製造，並繼續進行實驗量測與數值模擬比較，配合浮體運動計算最佳螺桿導程、衝程和轉盤直徑，再進行分析修正。

The main goal of the thesis is studying a wave energy conversion system with ball screw kits and its feasibility. The reason why adopting the ball screw kits is that we take advantage of its high efficiency of more than 90% of transforming slow linear motion into fast rotary motion. It can benefit the slow motion of the oscillating floating body at sea.
Based on panel method, the three-dimensional pulsating source is first used for calculating the related hydrodynamics coefficients with respect to different drafts and frequencies, and then these coefficients can be applied to simulate the motion of the floating body by the 4^th Runge-Kutta method in time domain. The precision of the calculation for the vertical motion of the wave energy conversion system will influence the accuracy of power estimation. Therefore, the present study simulates three kinds of vertical motions, including “Pure floating body”, “Floating body - Ball screw kits” and “Floating body - Ball screw kits - Generator” and compares them with experimental results.
It is found that with the increase of the wave period during the experiment, the motion of “Floating body with ball screw kits” would get larger in the same wave height. It is quite different from the motion of “floating body”. As a result, we assume that there is a time-delay between ball screw kits and floating body due to damping of mechanical system, and the duration of this time-delay depends on the length of the ball screw lead. To overcome this unsynchronized problem, relatively gentle waves are required for this system. Besides, for the proposed device, the lead of ball screw will determine whether it is laborious device or not.
However, the application of ball screw kits for wave energy conversion system faces a problem that due to the precision the mechanism is hardly in harmony with the floating body after processing and installation. Thus, we keep dedicating to the improvement of this system and its preliminary type. Furthermore, the optimal ball screw lead, the stroke and the rotary plate are determined by simulating the motion of the device. Also, the numerical results are verified by the experiments.

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