本研究主要目的在於利用過去已發展完善的船用流體力學理論與電腦模擬程式找出不同吃水及不同俯仰角情況下，對於船舶耐海性能之影響。
研究中共使用三艘商用船型，分別為油輪、貨櫃輪、散裝貨輪（Series 60）。並藉此比較不同方塊係數（CB）之船型在吃水、俯仰角、航行速度改變時，於耐海性能之差異。
本研究是以2D截片理論為基礎，比較不同吃水、俯仰角、航行速度時的船體運動反應振幅運算因子（Response Amplitude Operator）及附加阻力，並且用船模試驗結果來驗證程式模擬結果的正確性，幫助船舶於不同吃水時皆能選擇較佳的俯仰姿態及航行速度。惟受限於試驗設備，僅能進行迎浪（180度）和順浪（0度）的試驗。船模實驗除了估算船模整體於縱搖方向的轉動慣量（Moment of Inertia）外，還進行了零速度時的試驗，檢視船模在長波時的起伏是否與入射波同等。
本研究發現對貨櫃輪而言，艉俯姿態在起伏、縱搖、及附加阻力方面，皆有良好的表現，但在橫搖方面，表現最好則是艏俯1度的航行姿態；油輪方面，艉俯姿態在起伏、縱搖、及附加阻力方面，同樣皆有良好的表現，但在橫搖方面，表現最好則是縱平浮的航行姿態；而散裝貨輪於艉俯姿態時，雖仍有良好的起伏、縱搖、及附加阻力表現，但在橫搖項目中，艉俯姿態卻表現得最差，整體而言散裝貨輪於不同姿態時，皆各有優缺點，因此無法斷定其耐海性能最佳的航行姿態，僅能視情況及需求做出合適的選擇。

This research aims at figuring out the effect of different draft and trim angle of the ships on seakeeping performance by well-developed computer simulation program for ship hydrodynamics.
In the research, three different types of ships are to be compared. They are tanker ship, container ship, and bulk carrier ship (series 60), which all have different value of block coefficient (CB). The existing computer program based on strip theory is applied to calculate the ship motions and added resistance. Experimental tests are carried out to verify the results from the computer program. However, the tests only include longitudinal waves conditions due to the limitation of the facilities in NCKU Towing Tank. The experimental test also includes the measurement of moment of inertia for pitch motion of whole ship model.
From the results, we found that for container ship, sailing attitudes with trim by stern show good performance in heave motion, pitch motion, and added resistance generally. However, for roll motion, trim by bow 1° status shows the best performance. For tanker ship, sailing attitudes with trim by stern also show good performance in heave motion, pitch motion, and added resistance generally. However, for roll motion, even keel status shows the best performance. For series 60 ship, sailing attitude with trim by stern also has good performance in heave motion, pitch motion, and added resistance. However, trim by stern status has the worst performance in roll motion among all the sailing attitudes. Generally speaking, for series 60 ship, there is no best sailing attitude adapted to all conditions, because each sailing attitude has different advantages and drawbacks of seakeeping performance.

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