本研究主要透過時程領域模擬技巧來探討雙體船在縱向波作用之下兩船體間相對波高之分析。雙體船型目前已被廣泛運用，不論在軍事、運輸或著休閒育樂上都佔有一不可或缺的位置。雙體船型之遊艇主要運用在休閒育樂方面，故船隻之耐海性能與舒適性都是需要多加著墨的部份，因此在設計船型時會有許多方向需要考量。
本研究主要以二維截片理論搭配源點分佈法來計算入射、繞射以及輻射波勢流，並進一步計算出雙體結構的各項流體係數。本研究先透過由頻率領域建立出船體的各項流體係數之資料庫後，提供以四階Runge-Kutta數值方法作時程領域計算時運用，並以內插方法得到各瞬時之船體流體動力係數。接著再模擬出船體在時程領域中的運動狀態，並計算雙體結構物在時程領域中每一瞬間之船體間相對波高。本研究以一現有雙體遊艇船型做為探討與分析的對象，並討論透過變更船體間距之設計是否對船體運動及船體間相對波高產生影響。根據本文之模比較分析後發現，改變間距確實能達到改善的效果，並分析出此船型不適合航行之海況

This paper aims to study the relative elevation between two hull bodies for the twin-hull ship advancing under the longitudinal waves through time-domain simulation techniques. Catamaran has already been wildly used in many fields such as military, transportation and recreation. The catamaran type of yacht is mainly used in recreation. Therefore, the characteristics and stabilities of the vessel are all parts that need to be considered seriously. There are many factors needed to be considered when designing the ship type.
In this study, we used the 2D Strip theory and Potential theory method to calculate the incident, diffraction and radiation velocity potential, and then further calculate the hydrodynamic coefficients of the twin-hull body structure. At first, establish the database of related hydrodynamic coefficients of the hull from the frequency domain. Secondly, provide the databases for calculating the ship motion and wave elevation in time domain by using the fourth order Runge-Kutta numerical method. Consequently we can predict the relative wave elevation between the hulls at each instant in the time domain.
In the paper, we take an existing catamaran yacht as the calculation model to analyze how the design of the hull spacing affects the ship motion and the relative wave elevation between the hulls. According to the results, we can find that the suitable change of the hull spacing can indeed get some better effect. At the same time, we also can conclude that the original exiting ship design is not suitable for navigation at sea

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