基于NAPA的新型高速船船體型線及其參數(shù)化設(shè)計研究大摘要
對于高速船而言，由于航速的變化，其航態(tài)會因此發(fā)生改變，通過體積傅汝德數(shù)來表示高速船的相對速度，當(dāng)體積傅氏數(shù)位于1.0至3.0之間時，船舶的浮態(tài)與靜浮時有一定的變化，船首上浮，船尾下沉，具有一定程度的尾傾，船舶的浮力由排水體積產(chǎn)生的浮力與流體產(chǎn)生的升力組成。此時，盡管流體動力對浮力有一定的影響，但航態(tài)基本上仍處于排水型狀態(tài)，這類高速船稱為高速排水型船或過渡型高速船。
高速排水型船的船長傅汝德數(shù)通常集中在0.3至0.7之間，在此速度段中，圓舭船型具有良好的阻力性能，成為設(shè)計時的首選船型。然而，圓舭船型的橫搖性能較差，會對耐波性及舒適性帶來不利的影響；與此同時，折角船型（又稱V型船型或尖舭船型）在此速度段中的阻力性能略遜于圓舭船型，但折角船型的V型剖面直線斜升，與舷側(cè)板在舭部形成一個折角，一定程度上增加了橫搖阻尼，耐波性能優(yōu)于同尺度的圓舭船型。
綜合圓舭船型與折角船型各自的優(yōu)點(diǎn)，考慮設(shè)計一種圓舭折角船型，這種船型的前體與圓舭船型類似，后體則具有類似折角船型一樣的折角型線，希望通過這樣的結(jié)合，使得在具有相同主尺度和相近浮心縱向位置的情況下，圓舭折角船型具有類似圓舭船型一樣良好的阻力性能，而橫搖性能則要比圓舭船型有所改善，成為阻力性能和橫搖性能俱佳的船型之一。
型線設(shè)計是船型設(shè)計中的一個重要的環(huán)節(jié)，傳統(tǒng)的型線設(shè)計方法是參照優(yōu)秀的母型船型線或系列型線，經(jīng)過一定的變換和修改得到待設(shè)計船的型線。然而，一旦船型的某些設(shè)計要素有所改變，往往就需要重新設(shè)計型線，需要耗費(fèi)大量的時間和精力。參數(shù)化設(shè)計的理念是將某些船型要素和特征用參數(shù)的形式表達(dá)，使得船舶型線具有可視化、易生成和易修改的特點(diǎn)。
本文對圓舭船型和折角船型的船體型線及船體幾何形狀特征做了分析，在此基礎(chǔ)上，對圓舭折角船型的船體幾何形狀進(jìn)行了描述，經(jīng)過分析和篩選，將型線設(shè)計參數(shù)確定為27個。
本文以船舶設(shè)計軟件NAPA為開發(fā)平臺，結(jié)合典型的參數(shù)化設(shè)計理念，歸納出圓舭折角船型型線的參數(shù)化設(shè)計方法，通過相關(guān)的數(shù)學(xué)表達(dá)式連接設(shè)計參數(shù)，以NAPA Basic語言為工具開發(fā)編制了圓舭折角船型的參數(shù)化設(shè)計宏程序，整個船體形狀可由設(shè)計參數(shù)進(jìn)行驅(qū)動，在此基礎(chǔ)上，進(jìn)一步設(shè)計出具有相同主尺度及型排水體積、浮心縱向位置相近、折角型線長度與橫向底升角不同的系列船型，通過對上述船型的生成，驗證了該程序具有較強(qiáng)的靈活性和實(shí)用性。
型線設(shè)計完成后，需要對船型的性能進(jìn)行計算和評估，在現(xiàn)有的阻力計算圖譜和相關(guān)的回歸公式中，其查詢的依據(jù)和表達(dá)式大多與主尺度、尺度比和船型系數(shù)有關(guān)，在主尺度等指標(biāo)相同的情況下，阻力計算圖譜和相關(guān)的回歸公式不能較好的反映船型變化對阻力的影響及程度。隨著數(shù)值仿真軟件的不斷完善和進(jìn)步，利用軟件對船舶進(jìn)行和阻力計算和運(yùn)動數(shù)值仿真模擬已成為可能，其可靠性和準(zhǔn)確程度已經(jīng)得到了一定程度的認(rèn)可。
本文針對參數(shù)化宏程序生成的模型，利用Fluent軟件對其阻力性能進(jìn)行了計算分析，利用Maxsurf軟件對其橫搖性能進(jìn)行了研究；通過綜合分析和比較，不僅驗證了圓舭折角船型的綜合性能要優(yōu)于同尺度的圓舭船型，而且當(dāng)全船分為10站，折角型線長度在1.5站左右時，圓舭折角船型可以取得較好的綜合性能，同時為圓舭折角高速船性能的進(jìn)一步評估提供了借鑒。

關(guān)鍵詞 圓舭折角；型線；參數(shù)化設(shè)計；NAPA；阻力；橫搖























Abstract
Because of the change of the speed, the sailing condition of the high speed craft may change, it can be divided by the Froude number based on volume, when the Froude number between 1.0 and 3.0, the bow of the craft may rise and the aft may fill down, the buoyancy of the craft equals to the sum of volume of displacement and fluid lift force. At this moment, although lift force may affect the buoyancy, the sailing is still in the condition of displacement, crafts at this condition are named displacement crafts or transition crafts.
The Froude numbers based on length of displacement crafts are concentrated in the region between 0.3 and 0.7, at this speed region, round bilge craft has perfectly resistance performance and become the first consideration among other craft configurations. However, the rolling performance of round craft may not good and may has negative effect to seakeeping performance and comfortable. Meanwhile, knuckle bilge craft (also named V-craft) has V cross sections and enhance the rolling damping, the seakeeping performance is better than round bilge craft and resistance performance is briefly worse than round bilge craft.
According to the advantages of the two crafts, a new high speed craft named round & knuckle craft can be designed, the front hull of the craft may identical to round craft and rear hull may identical to knuckle craft. It hopes that in the same dimensions and similar position of longitudinal center of buoyancy, this craft’s resistance performance is as well as round craft and rolling performance is as well as knuckle craft.
Hull lines design is a crucial step in craft design, the traditional method of hull lines design is obeying to the excellence model crafts and series crafts, after changing their dimensions and other factors, new hull lines can be obtained. However, while the design factors have to be change, the hull lines need to be crated again, and this method have to spend so much time and energy. Parametric design can solve this problem, this method use some design parameters to express the hull lines, and hull lines can be visible..