船舶與海洋工程畢業(yè)設(shè)計(jì)片列四體船初穩(wěn)性計(jì)算

1、<p><b>　　本科畢業(yè)論文</b></p><p><b>　?。?0 屆）</b></p><p>　　片列四體船初穩(wěn)性計(jì)算</p><p>　　所在學(xué)院 </p><p>　　專業(yè)班級(jí) 船舶與海洋工程

2、 </p><p>　　學(xué)生姓名 學(xué)號(hào) </p><p>　　指導(dǎo)教師 職稱 </p><p>　　完成日期 年 月 </p><p><b>　　目 錄</b></p

3、><p><b>　　摘要3</b></p><p><b>　　1 前言5</b></p><p>　　1.1立題背景及研究意義6</p><p>　　2 四體船初穩(wěn)性公式推導(dǎo)8</p><p>　　2.1片列四體船船體分布圖及型線圖8</p><

4、p>　　2.2 外側(cè)兩片體的慣性矩推導(dǎo)10</p><p>　　2.3 內(nèi)側(cè)兩片體的慣性矩推導(dǎo)10</p><p>　　2.4 橫穩(wěn)心半徑推導(dǎo)10</p><p>　　2.5 縱穩(wěn)心半徑推導(dǎo)11</p><p>　　2.6浮心高計(jì)算公式11</p><p>　　2.7初穩(wěn)性公式11</p>

5、<p>　　3 四體船初穩(wěn)性計(jì)算12</p><p>　　3.1 船型，主尺度及船體型線值12</p><p>　　3.2 ，，，，計(jì)算表15</p><p>　　3.3 ，，，TPC計(jì)算表33</p><p>　　3.4 計(jì)算表34</p><p>　　3.5 KB計(jì)算表35</p&g

6、t;<p>　　3.6 計(jì)算表36</p><p>　　3.7 MTC計(jì)算表37</p><p>　　3.8 計(jì)算表38</p><p>　　4 四體船靜水力曲線繪制39</p><p>　　4.1 四體船靜水力曲線所需數(shù)據(jù)39</p><p>　　4.2 繪制靜水力曲線圖41</p&g

7、t;<p>　　5 結(jié)論和展望45</p><p><b>　　5.1結(jié)論45</b></p><p><b>　　5.2展望45</b></p><p><b>　　6 致謝46</b></p><p><b>　　[參考文獻(xiàn)]47</

8、b></p><p>　　附錄一：外文翻譯................................................47</p><p><b>　　摘要</b></p><p>　　多體船的設(shè)計(jì)概念是通過采用大長(zhǎng)寬比的主船體來有效減小興波阻力，而由此帶來的穩(wěn)性損失由兩個(gè)或更多的側(cè)片體來彌補(bǔ)。本文在單體船初穩(wěn)性計(jì)算的

9、基礎(chǔ)下，進(jìn)行對(duì)多體船初穩(wěn)性研究，分析了側(cè)體跨距、排水量等參數(shù)對(duì)于初穩(wěn)性的影響。</p><p>　　本文根據(jù)單體船的初穩(wěn)性計(jì)算，推導(dǎo)四體船橫向慣性矩和縱向慣性矩，以及根據(jù)船模而獲得的大量型線值，再利用船舶在靜止正浮狀態(tài)下浮性和初穩(wěn)性的基本原理及其計(jì)算，從而繪制靜水力曲線圖。</p><p>　　船舶穩(wěn)性研究是船舶行業(yè)中一個(gè)非常重要、非常復(fù)雜的課題。近年來,多體船引起廣泛關(guān)注，滿足穩(wěn)性要求是

10、多體船型設(shè)計(jì)開發(fā)的基本前提。期望能對(duì)今后的四體船穩(wěn)性研究有所幫助。</p><p>　　[關(guān)鍵詞] 四體船；初穩(wěn)性；靜水力曲線圖；慣性矩</p><p>　　Calculation of initial stability of Four-body ship</p><p>　　[Abstract] The design concept of multi-hul

11、l boats use a large aspect ratio of the main hull to reduce the wave resistance effectively.Then the resulting loss of stability makes up by two or more pieces body.In the basis of the initial stability calculation of si

12、ngle ship,we’ll reseach the initial stability of the multi-hull boat,analyze the impact of initial stability from side of the body span,displacement and other parameters .</p><p>　　According to the initial s

13、tability calculation of the single ship,we can derive horizontal moment of inertia and vertical moment of inertia of four-body ship.Then according to ship model we get a large number of profile values,use ship in the sta

14、tionary state and the basic principles and calculation of initial stability to draw the curves of hydrostatic.</p><p>　　Stability of the ship in the shipbuilding industry is a very important and complex issu

15、e.In recent years,multi-hull boats caused widespread concern.Meet the stability requirements are the basic of multi-body ship’s design and development.Looking forward to help the study of four-body ship in the future.<

16、;/p><p>　　[Key Words] Four-body ship;metacentric;hydrostatic curves;monent of inertia</p><p><b>　　1 前言</b></p><p>　　Daniel Tollet最早提出了四體船設(shè)計(jì)概念，并于1990在法國主持建造了第一艘四體船“Alexander

17、”號(hào)。它長(zhǎng)17.5m，重13.5噸，由四個(gè)300馬力的發(fā)動(dòng)機(jī)推進(jìn)，航速達(dá)到了60節(jié)?！癆lexander”號(hào)在法國地中海沿岸航行了五年，運(yùn)載了大量的旅客。</p><p>　　20世紀(jì)90年代，人們進(jìn)行了對(duì)各種尺寸四體船的設(shè)計(jì)。法國的大型鋼鐵企業(yè)SOLLAC看到了高強(qiáng)度鋼質(zhì)大型四體船的市場(chǎng)，于是贊助122~175m長(zhǎng)的四體貨船的設(shè)計(jì)工作。26m長(zhǎng)的四體貨船“Roxelane”號(hào)在法國建成，并在加勒比海的馬提尼克成

18、功試航。它的設(shè)計(jì)航速只有30節(jié)。美國的營造商在諾?？说腗oon Engineering公司訂購了另外一艘26m長(zhǎng)時(shí)速高達(dá)50節(jié)的鋁質(zhì)四體渡船。[14]</p><p>　　四體船是指采用四支柱、四下體式的小水線面船型，下體都采用球鼻艏和尖錐艉型；前雙下體問距小于后雙下體間距，這有利于高速航行和保持高耐波性；前后四下體的線型和重量分配均采用優(yōu)化設(shè)計(jì)，以減少阻力、提高推進(jìn)效率和航速、改善運(yùn)動(dòng)姿態(tài)。四體船與三體和五體船

19、有著極大的不同。它設(shè)計(jì)獨(dú)特，是一種高速、淺吃水、航行平穩(wěn)、尾流很小的高性能船舶。四體船的四個(gè)窄楔形船體，可以產(chǎn)生水動(dòng)升力，并且在船體間的窄帶空間里還可以由空氣動(dòng)力產(chǎn)生附加的升力，因此推進(jìn)器的需求功率可以比普通船舶小得多。另外伴隨著氣動(dòng)升力，氣體在船底可以產(chǎn)生氣墊來減小阻力。四體船的四個(gè)船體并排展開，這樣它就有更好的可靠性和幸存機(jī)會(huì)，因?yàn)橐粋€(gè)船體出了問題并不會(huì)很容易的傳到其它的船體。</p><p>　　船舶穩(wěn)性研

20、究是船舶行業(yè)中一個(gè)非常重要、非常復(fù)雜的課題。由于船舶穩(wěn)性涉及環(huán)境條件、船舶技術(shù)條件和操作要素等許多因素，故而穩(wěn)性的改善可能又會(huì)導(dǎo)致船舶其他性能的惡化。因此這一方面研究雖有幾百年的歷史，至今還沒有形成一個(gè)理論上成熟的綜合考慮船型要素、環(huán)境條件和傾覆機(jī)理等因素的穩(wěn)性衡準(zhǔn)。[9]</p><p>　　船舶穩(wěn)性就是船舶在外力作用下，船舶發(fā)生傾斜而不致顛覆，當(dāng)外力的作用消失后，仍能回復(fù)到原來位子的能力。判斷船舶是否具有足夠

21、的穩(wěn)性，有其一定的衡量指標(biāo)。這些指標(biāo)與船舶的主尺度、形狀以及裝載情況等有密切關(guān)系。船舶的穩(wěn)性問題分為兩部分進(jìn)行研究，此文研究的是船舶的初穩(wěn)性（或稱小傾角穩(wěn)性）——一般指傾斜角度小于10°～15°或上甲板邊緣開始入水前的穩(wěn)性。</p><p>　　在穩(wěn)性研究中發(fā)現(xiàn)，船舶在一定排水量下產(chǎn)生微小橫傾時(shí)，橫穩(wěn)性高，越大，復(fù)原力矩也越大，也就是抗傾斜力矩的能力越強(qiáng)。而初穩(wěn)性是衡量船舶初穩(wěn)性的重要指標(biāo)，可

22、寫成：</p><p>　　概括說來，其中最重要的問題是，弄清浮心B、重心G和穩(wěn)心M的位置以及三者之間的關(guān)系。</p><p>　　船舶在外力作用下導(dǎo)致船舶的傾斜，造成浮心的移動(dòng)，從而橫穩(wěn)心半徑即：</p><p><b>　　縱穩(wěn)心半徑即：</b></p><p>　　而對(duì)于四體船的穩(wěn)性研究，超細(xì)長(zhǎng)多體船的設(shè)計(jì)概念就是

23、通過采用大長(zhǎng)寬比的片列來有效減少興波阻力，而由此帶來的穩(wěn)性損失由片體來彌補(bǔ)。增加片體從而使橫向慣性矩增大，增加橫穩(wěn)心半徑。</p><p>　　本文將利用靜水力學(xué)方法計(jì)算片列四體船的初穩(wěn)性以及繪制靜水力曲線。</p><p>　　1.1立題背景及研究意義</p><p>　　在美國，人們對(duì)小水線面船了解最多的可能是在夏威夷，那里是小水線面船開發(fā)、設(shè)計(jì)、建造、試驗(yàn)、營

24、運(yùn)的一個(gè)中心。進(jìn)入90年代，許多人曾在夏威夷有風(fēng)浪時(shí)乘坐小水線面旅游觀光船到海上去觀浪景別有情趣。更令人矚目的是洛克希德·馬丁集團(tuán)在“海影"號(hào)隱身試驗(yàn)船基礎(chǔ)上研制的“司萊斯"號(hào)多功能公務(wù)船，它是一型小水線面四體船。“司萊斯"號(hào)排水量約177噸，總長(zhǎng)約31.7米，前后下體垂線間長(zhǎng)約24.9米，最大寬約16.8米，上層建筑寬約12.5米，上層建筑底距水面約2.14米，下體最大處直徑約為3.04米，干

25、舷約3.36米，吃水約4.27米；在船中后部的有效負(fù)載模塊重約50噸，長(zhǎng)約17.4米，寬約13.1米?！八救R斯"號(hào)采用四短斜支柱、四下體式小水線面船型，各下體都采用球鼻首和尖錐尾型，下體長(zhǎng)相對(duì)較短，前雙下體間距小于后雙下體，中心線錯(cuò)位能降低凱爾文尾流，不僅利于高速航行，而且在港灣內(nèi)航行時(shí)也對(duì)岸壁及其它船只無影響，特別有利于保持高耐波性；前后四下體線型、流體布局、重量分配經(jīng)優(yōu)化設(shè)計(jì)，達(dá)到減少阻力、提高推進(jìn)效率與航速、改善運(yùn)動(dòng)姿態(tài)

26、的目的。美國海軍試用該船作為監(jiān)測(cè)雷達(dá)的海上平臺(tái)，執(zhí)行跟蹤火箭飛行試驗(yàn)任務(wù)；美國</p><p>　　縱觀國際高速船的技術(shù)開發(fā)與市場(chǎng)發(fā)育情況，不難發(fā)現(xiàn)80年代中期以來，各類高速船已完全進(jìn)入實(shí)用化、商業(yè)化階段，船型已基本形成系列。高速多體船與其他性能船相比，除了甲板面積寬敞、穩(wěn)性好及吃水較小外，尚具有技術(shù)要求不太復(fù)雜、成本較低、易于發(fā)展；沒有易損壞的或復(fù)雜的部件、使用可靠、維修保養(yǎng)方便等優(yōu)點(diǎn)。超細(xì)長(zhǎng)的船體使其剩余阻力

27、大幅度降低，船長(zhǎng)的增加對(duì)改善耐波性有利，甲板面積小和穩(wěn)性不足的問題則通過采用多體結(jié)構(gòu)來解決。</p><p>　　而近年來，雙體船、三體船以及五體船不斷的發(fā)展，四體船的有關(guān)研究相應(yīng)不足，而對(duì)于多體船，它在外力的作用下產(chǎn)生傾斜以后，水下部分體積的形狀發(fā)生了變化，體積行心（浮心）向傾斜的一側(cè)移動(dòng)，所以，船體的穩(wěn)性研究是船舶制造的前提。</p><p>　　四體船與三體和五體船有著極大的不同。它

28、設(shè)計(jì)獨(dú)特，是一種高速、淺吃水、航行平穩(wěn)、尾流很小的高性能船舶。四體船的四個(gè)窄楔形船體，可以產(chǎn)生水動(dòng)升力，并且在船體間的窄帶空間里還可以由空氣動(dòng)力產(chǎn)生附加的升力，因此推進(jìn)器的需求功率可以比普通船舶小得多。另外伴隨著氣動(dòng)升力，氣體在船底可以產(chǎn)生氣墊來減小阻力。四體船的四個(gè)船體并排展開，這樣它就有更好的可靠性和幸存機(jī)會(huì)，因?yàn)橐粋€(gè)船體出了問題并不會(huì)很容易的傳到其它的船體。</p><p>　　在推進(jìn)方面，四體船在四個(gè)船體

29、上布置2個(gè)螺旋槳，因此比同排水量的單體船和雙體船需要的推進(jìn)功率較小。但對(duì)較小的四體船來說，較低的船體太狹窄，所以很難在兩個(gè)船體上布置足夠的功率，不過對(duì)于大型的四體船則不存在這個(gè)問題，因?yàn)楣β拭芏入S著功率的增加而迅速增大。對(duì)于小型四體船可以采用舷外側(cè)發(fā)動(dòng)機(jī)，這樣就避免了在狹窄船體上布置動(dòng)力的難題。</p><p>　　在阻力方面，一般認(rèn)為：四體船的濕面積較大，必然會(huì)產(chǎn)生很大的摩擦阻力；四個(gè)船體彼此排列較緊密必然會(huì)產(chǎn)

30、生強(qiáng)烈的相互影響力和多余的阻力；另外船體間距較小，也會(huì)阻礙水流和氣流從而增加阻力。</p><p>　　其實(shí)不然，四體船的四個(gè)及其狹長(zhǎng)的船體有著尖角而且沒有側(cè)翼，這樣就會(huì)受到非常小的興波阻力。水動(dòng)和氣動(dòng)升力也會(huì)減少浸沒水中的船體表面積。船體間的氣體壓力也可以減少波浪的產(chǎn)生和波浪阻力。[14]</p><p>　　2 四體船初穩(wěn)性公式推導(dǎo)</p><p>　　假定四體

31、船四個(gè)片體都為相同并列片體，船舶在等體積小角度傾斜過程中，浮心移動(dòng)曲線是以穩(wěn)心M為圓心、為半徑的圓?。˙為正浮時(shí)的浮心位置）,M點(diǎn)位置保持不變，浮力作用線始終通過M。</p><p>　　根據(jù)假定，在外力作用下發(fā)生小角度橫傾時(shí)，四體船從水線等體積傾斜到水線時(shí)，傾斜前后的排水體積大小保持不變，并且前后兩水線面的交線0-0軸通過傾斜前的水線面的漂心。將和看作是中間有一段被掏空的楔形體。假定兩片體之間的跨距為b。[15

32、]</p><p>　　2.1片列四體船船體分布圖及型線圖</p><p>　　片列四體船側(cè)體分布圖</p><p><b>　　單片體型線圖</b></p><p>　　2.2 外側(cè)兩片體的慣性矩推導(dǎo)</p><p>　　由上假定，外側(cè)兩片體距中的跨距為，為側(cè)體自身正浮水線面對(duì)各自縱向中心軸線的

33、慣性矩， I為外側(cè)片體慣性矩總和，即：</p><p>　　從而可得出外側(cè)兩片體的橫向慣性矩為：</p><p>　　式中：為外側(cè)片體水線面面積對(duì)通過中線的橫向慣性矩。</p><p>　　為片體正浮水線面面積</p><p>　　外側(cè)兩片體縱向慣性矩：</p><p>　　式中：為外側(cè)片體水線面面積對(duì)通過漂心的縱向慣

34、性矩。</p><p>　　為片體正浮水線面面積</p><p>　　2.3 內(nèi)側(cè)兩片體的慣性矩推導(dǎo)</p><p>　　由上假定，內(nèi)側(cè)兩片體距中的跨距為，因每個(gè)片體都相同，為側(cè)體自身正浮水線面對(duì)各自縱向中心軸線的慣性矩，為片體正浮水線面面積，I為內(nèi)側(cè)體慣性矩總和，即：</p><p>　　從而可得出內(nèi)側(cè)兩片體的橫向慣性矩為：</p&g

35、t;<p>　　式中：為內(nèi)側(cè)片體水線面面積對(duì)通過中線的橫向慣性矩。</p><p>　　為片體正浮水線面面積</p><p>　　內(nèi)側(cè)兩片體的縱向慣性矩為：</p><p>　　式中：為外側(cè)片體水線面面積對(duì)通過漂心的縱向慣性矩。</p><p>　　為片體正浮水線面面積</p><p>　　2.4 橫穩(wěn)心

36、半徑推導(dǎo)</p><p>　　船舶在橫傾角時(shí)，浮心自原來的位置B沿某一曲線移至當(dāng)為微小角度時(shí)，曲線可看做是圓弧的一段，M點(diǎn)位曲線的圓心，而=為曲線的半徑。這樣船舶在微小角度傾斜過程中，浮力作用線均通過M點(diǎn)，因此，M點(diǎn)稱為橫穩(wěn)心或初穩(wěn)心，（或以r表示）稱為橫穩(wěn)心半徑或初穩(wěn)心半徑。</p><p>　　當(dāng)為微小角度時(shí)，≈=，因，則得橫穩(wěn)心半徑：</p><p>　　2.

37、5 縱穩(wěn)心半徑推導(dǎo)</p><p>　　船舶在等體積縱傾時(shí)的情況，與上面所討論的橫傾情況相同，完全可以得出類似與橫傾狀況的結(jié)果。</p><p>　　等體積傾斜水線面與WL相交于通過漂心F的橫向軸線。</p><p><b>　　浮心的移動(dòng)距離為</b></p><p>　　縱穩(wěn)心半徑(或以R表示)為</p>

38、<p>　　2.6浮心高計(jì)算公式</p><p>　　，為全船、4個(gè)片體正浮時(shí)的排水體積，=4*；4個(gè)片體的浮心高為,</p><p>　　式中：為片體的排水體積</p><p><b>　　為片體的浮心高</b></p><p>　　為4個(gè)片體的排水體積總和</p><p><

39、;b>　　是全船的浮心高</b></p><p><b>　　2.7初穩(wěn)性公式</b></p><p>　　船舶橫傾某一小角度時(shí)，如設(shè)船上的貨物未移動(dòng)，其重心位置G仍保持不變，而浮心則自B點(diǎn)移至點(diǎn)。此時(shí)重力W的作用點(diǎn)G和浮力的作用點(diǎn)不在同一鉛垂線上，因而產(chǎn)生了一個(gè)復(fù)原力矩，即</p><p><b>　　式中：——復(fù)

40、原力矩</b></p><p>　　——橫穩(wěn)性高，亦稱為初穩(wěn)性高。</p><p>　　當(dāng)橫傾角度較小時(shí)，，所以，此式被稱為初穩(wěn)性公式。</p><p>　　而初穩(wěn)性高是衡量船舶初穩(wěn)性的重要指標(biāo)，可寫成</p><p>　　式中：——浮心高度（或以浮心垂向坐標(biāo)表示）</p><p>　　——初穩(wěn)性半徑（或稱

41、橫穩(wěn)心半徑）</p><p>　　——重心高度（或以重心垂向坐標(biāo)表示）</p><p>　　3 四體船初穩(wěn)性計(jì)算</p><p>　　3.1 船型，主尺度及船體型線值</p><p><b>　　船型：片列四體船</b></p><p><b>　　主尺度：</b></

42、p><p><b>　　表1 主尺度</b></p><p><b>　　主體型線：</b></p><p><b>　　表2 主體半寬值</b></p><p>　　3.2 ，，，，計(jì)算表</p><p>　　從型線圖可得一下數(shù)據(jù)：</p>

43、<p><b>　　d=2.4m</b></p><p>　　δL=0.3436m</p><p>　?。?/3）δL=0.2291</p><p>　　2（δL）*（δL）*（δL）=0.0811</p><p>　　片體之間的跨距為15.98</p><p>　　表3 不同吃水下的船

44、長(zhǎng)及船寬</p><p>　　表4第一組數(shù)據(jù)（水線號(hào)為0T）</p><p>　　表5 第二組數(shù)據(jù)（水線號(hào)為1T）</p><p>　　表6 第三組數(shù)據(jù)（水線號(hào)為2T）</p><p>　　表7 第四組數(shù)據(jù)（水線號(hào)為3T）</p><p>　　表8 第五組數(shù)據(jù)（水線號(hào)為4T）</p><p>　

45、　表 9 第六組數(shù)據(jù)（水線號(hào)為5T）</p><p>　　表10 第七組數(shù)據(jù)（水線號(hào)為6T）</p><p>　　表11 第八組數(shù)據(jù)（水線號(hào)為7T）</p><p>　　表12 第九組數(shù)據(jù)（水線號(hào)為8T）</p><p>　　表13 第十組數(shù)據(jù)（水線號(hào)為9T）</p><p>　　表14 第十一組數(shù)據(jù)（水線號(hào)為10T）

46、</p><p>　　表15 第十二組數(shù)據(jù)（水線號(hào)為11T）</p><p>　　表16 第十三組數(shù)據(jù)（水線號(hào)為12T）</p><p>　　表 17 第十四組數(shù)據(jù)（水線號(hào)為14T）</p><p>　　表18 第十五號(hào)數(shù)據(jù)（水線號(hào)為16T）</p><p>　　表19 第十六號(hào)數(shù)據(jù)（水線號(hào)為18T）</p>

47、;<p>　　表20 第十七號(hào)數(shù)據(jù)（水線號(hào)為20T）</p><p>　　3.3 ，，，TPC計(jì)算表</p><p>　　表21 ，，，TPC計(jì)算表（吃水變化量T=0.24m T/2=0.12m， 海水的重量密度w=1.025t/m3）</p><p><b>　　3.4 計(jì)算表</b></p><p>

48、;<b>　　表22 計(jì)算表</b></p><p><b>　　3.5 KB計(jì)算表</b></p><p><b>　　表23 KB計(jì)算表</b></p><p><b>　　3.6 計(jì)算表</b></p><p><b>　　表24 計(jì)算表&

49、lt;/b></p><p>　　3.7 MTC計(jì)算表</p><p>　　表25 MTC計(jì)算表</p><p><b>　　3.8 計(jì)算表</b></p><p><b>　　表26 計(jì)算表</b></p><p>　　4 四體船靜水力曲線繪制</p>

50、<p>　　4.1 四體船靜水力曲線所需數(shù)據(jù)</p><p>　　表27 靜水力曲線繪制數(shù)據(jù)表</p><p>　　4.2 繪制靜水力曲線圖</p><p>　　浮心垂向坐標(biāo)及水線面面積曲線</p><p>　　縱穩(wěn)心半徑及橫穩(wěn)心半徑曲線</p><p>　　每厘米吃水噸數(shù)TPC及每厘米縱傾力矩MTC曲線圖&

51、lt;/p><p>　　型排水體積及總排水量曲線圖</p><p>　　浮心縱向坐標(biāo)及漂心縱向坐標(biāo)曲線圖</p><p>　　菱形系數(shù)及方形系數(shù)曲線圖</p><p>　　水線面系數(shù)及中橫剖面系數(shù)曲線圖</p><p><b>　　5 結(jié)論和展望</b></p><p>　　本

52、文首先利用靜力學(xué)對(duì)四體船的初穩(wěn)性公式進(jìn)行推導(dǎo)，然后進(jìn)行四片體的布置及跨距設(shè)定，對(duì)一艘四體船進(jìn)行了初穩(wěn)性計(jì)算。</p><p><b>　　5.1結(jié)論</b></p><p>　?。?）經(jīng)過這次公式推導(dǎo)中，發(fā)現(xiàn)片體間的跨距對(duì)值有較大的影響，增大跨距對(duì)改善初穩(wěn)性起決定性的作用。</p><p>　?。?）四體船的初穩(wěn)性可以通過改變側(cè)體的尺度和片體跨

53、距來調(diào)節(jié)。以獲得合適的初穩(wěn)性高。</p><p>　?。?）經(jīng)過初穩(wěn)性計(jì)算，四體船可以獲得較大的初穩(wěn)性高，從而能夠提高在受損情況下的生存能力。片體不僅可以增加穩(wěn)性高，橫搖時(shí)還可以增大橫搖阻尼。</p><p>　　除此之外，在圖形的輸出上也遇到了不少的麻煩，為了能得到準(zhǔn)確美觀的圖形，經(jīng)過了反復(fù)的修改、調(diào)整、打印，最后得到了比較滿意的圖紙，雖然在操作上比較繁瑣但excel的使用提高了在制作時(shí)

54、的效率，結(jié)果令人欣慰。</p><p><b>　　5.2展望</b></p><p>　　船舶的穩(wěn)性是船舶研究的重要性能之一，對(duì)于四體船的發(fā)展還在起步階段，在四體船初穩(wěn)性的計(jì)算過程中，沒有更多的參照，突現(xiàn)不出四體船在穩(wěn)性方面的優(yōu)點(diǎn)。希望今后，能通過采用不同尺度、布置位子不同的片體方案，進(jìn)行穩(wěn)性計(jì)算，從而進(jìn)行對(duì)比，對(duì)今后的四體船研究能有更好的發(fā)現(xiàn)。</p>

55、<p><b>　　[參考文獻(xiàn)]</b></p><p>　　[1] Apostolos Papanikolaou ,Eleftheria Eliopoulou.On the development of the new harmonised damage stability regulations for dry cargo and passenger ships[J]. R

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57、(1618-1630)</p><p>　　[3]劉烽杰. 船舶穩(wěn)性研究[J].中國水運(yùn).2007</p><p>　　[4]高家鏞. 船舶穩(wěn)性研究的現(xiàn)狀及展望[J].上海造船.2003,(1).</p><p>　　[5]許統(tǒng)銓. 多體船技術(shù)開發(fā)[J] .交通部上海船舶運(yùn)輸科學(xué)研究所學(xué)報(bào).2000,(2).</p><p>　　[6]李培勇

58、,裘泳銘,顧敏童,許統(tǒng)銓.多體船型完整穩(wěn)性的計(jì)算，上海交通大學(xué)學(xué)報(bào)，2002,(11).</p><p>　　[7]尤煒呈. 散貨船完整穩(wěn)性計(jì)算系統(tǒng)WHUT-ISCS開發(fā)武漢理工大學(xué)[D].2008.</p><p>　　[8]王云煌. 小傾角船舶穩(wěn)性[J]世界海運(yùn) , 1995,(06) .</p><p>　　[9]張文斌,姚震球,蔣志勇.船舶穩(wěn)性理論研究的方法

59、及進(jìn)展[J].華東船舶工業(yè)學(xué)院學(xué)報(bào)(自然科學(xué)版),2002,(01).</p><p>　　[10]杜文塔,陳劍利.多體船在軍事領(lǐng)域前期波瀾[J].國防科技,2003</p><p>　　[11]王研.關(guān)于大型高速多體船船型的探討.船舶物資與市場(chǎng)，2002.</p><p>　　[12]王志華.美“司萊斯”號(hào)研究船為小水線面四體船[J].船電技術(shù)，2009（12）.

60、</p><p>　　[13]劉淮.多體船在軍事上的應(yīng)用[J].船舶物資與市場(chǎng)，2001.</p><p>　　[14]陳劍利.四體船[OL]. http://blog.sina.com.cn/s/blog_49192ff20100095t.html</p><p>　　[15]盛振邦、劉應(yīng)中. 《船舶原理上冊(cè)》. 上海交通大學(xué)出版社，2005.7.</p&g

61、t;<p>　　FLOATABILITY AND STABILITY OF SHIPS:</p><p>　　23 CENTURIES AFTER ARCHIMEDES</p><p>　　Alberto Francescutto </p><p>　　Department of Naval Architecture, Ocean and Enviro

62、nmental Engineering, </p><p>　　University of Trieste, Via A. Valerio 10, 34127 Trieste, Italy </p><p>　　e-mail: francesc@units.it </p><p>　　Apostolos D. Papanikolaou </p><

63、;p>　　Ship Design Laboratory, National Technical University of Athens </p><p>　　Heroon Polytechniou 9, 15773 Athens, Greece </p><p>　　e-mail: papa@deslab.ntua.gr</p><p>　　ABSTRACT

64、 In this paper the main developments in ship buoyancy, stability and subdivision of ships since the milestone formulation of the basic laws of floatability and stability of floating bodies by Archimedes are reviewed. T

65、he continuous progress in the safety of ships as most effective transportation means and the links of the fundamental Archimedean studies to the modern naval architectural approaches to ship stability, design and safety

66、are critically commented. </p><p>　　1. INTRODUCTION </p><p>　　Man has travelled since thousands of years throughout the oceans without first knowing how and why it was possible. The basic laws o

67、f hydrostatics of floating bodies were introduced by the Great Archimedes in 300 B.C. It is well established that he was the first to formulate the basic law of buoyancy and eventually floatability; namely, the ability o

68、f a solid body to float is trivially related to the equilibrium and balance of the gravitational (weight) and the hydrostatic pressure (buoyancy) fo</p><p>　　Many centuries after Archimedes, they were the Fr

69、ench P. Bouguer (1746) with “Traité du Navire” and the Swiss L. Euler (1749) with “Scientia Navalis”, who worked out (almost simultaneously) the principles of modern ship buoyancy and stability, of fluid resistanc

70、e and a series of other specific problems of Ship Theory on the basis of Newtonian mechanics. The important notion of stability “metacenter” stems from Bouguer and was never used by Euler, who was not familiar with t

71、his terminology.</p><p>　　During the industrial revolution in the 19th Century, the first ironclad steam powered and very large ships were introduced (Great Eastern, 1858), thus, the demand for even more tho

72、rough and practical approaches to ship’s floatability and stability rapidly increased. Historical develop-ments in ship’s subdivision (and damage stability, which is ship’s stability in case of loss of her watertight int

73、egrity, e.g., by collision, grounding etc.) in the 20th Century were marked by the most notable shi</p><p>　　More recent scientific and regulatory developments in the intact and damage ship stability concer

74、n the dynamic stability of ships in waves and considerations of ship’s overall safety against capsize and other hazards for the various types of merchant (and naval) ships, with emphasis on the stability of passenger sh

75、ips, for which the risk of loss of many lives on-board should be kept minimal. After the loss of Estonia in 1994, particular emphasis has been placed on improving the design of ferri</p><p>　　Developments in

76、 the methodology of ship’s stability show the traditional deterministic assessment methods more and more being displaced by probabilistic and first principles approaches to ship’s stability and safety, which are eventua

77、lly integrated in risk-based design and operational pro-cedures. For a recent review of developments in the intact and damage stability of ships, see reviews by A. Francescutto (2007) and A. Papanikolaou (2007). Neverth

78、eless, the fundamental laws of buoyancy and s</p><p>　　2. GENERALIZATIONS OF ARCHIMEDES’ PRINCIPLE </p><p>　　Archimedes’ floatability principle may be derived from the simple, yet revolutionary

79、, observation that a solid body floats in water (or at least has a reduced weight), although subject to its weight due to gravity because of an upward force, namely buoyancy, which is proportional to the displaced water

80、mass. There is, however, an important difference in the characteristics of the two acting forces, i.e., the body’s weight and buoyancy: the first is a force acting at the center of mass of the bod</p><p>　　A

81、n important departure from Archimedes’ principle is related to the buoyancy in a liquid in motion under the effect of some external disturb-ance: typical is the case of a body floating in the presence of waves as more or

82、 less unavoidably happens to actual ships. This generalization does not allow us to use the simple calculations of volumes and centers of volumes of ship’s hull, when floating in calm water, because nor the instantaneous

83、 pressures on the body (which include hydrodynamic effects)</p><p>　　For the purpose of the following discussion, focusing on buoyancy and stability, we just note that besides modern numerical simulation met

84、hods, present practical approaches to ship’s stability mostly focus on static stability characteristics in calm water, whereas those explicitly taking into account the effect of waves (ship dynamics) are based on the Fr

85、oude-Krylov (Froude, 1861, Krylov, 1898) hypothesis and may eventually consider further simplifications of the wave effects based on the assum</p><p>　　3. THE LINK OF SHIP BUOYANCY, STABILITY </p>&

86、lt;p>　　AND SUBDIVISION TO THE ARCHIMEDEAN WORK </p><p>　　Sinking because of insufficient buoyancy and capsizing due to insufficient stability are two of the most important threats to ship’s survivability

87、at sea. The safety from sinking and capsizing is thus an important part of the safety of navigation with the entailed safety of the life of people onboard, of carried cargo and with respect to the protection of environme

88、nt in waterborne transportation. The most characteristic discipline of Naval Architecture known as Buoyancy and Stability is directly</p><p>　　4. INTACT STABILITY OF SHIPS – RECENT REGULATORY </p>&l

89、t;p>　　DEVELOPMENTS AND TRENDS </p><p>　　The latest revision of the International Intact Stability Code, which started in 2001, led to the 2008 IS Code. Further to this, the need for new criteria, based o

90、n more realistic physical approaches was stressed and a rational updated plan of action was decided, consisting in the development of: </p><p>　　–vulnerability criteria to identify the possible susceptibilit

91、y of a ship to partial (excessive roll angles/accelerations) or total (capsizing) stability failures for each mode; </p><p>　　–procedures for direct assessment of: stability failures explicitly taking into a

92、ccount the dead ship condition, the stability variations in waves (pure loss of stability and parametric resonance) and the connections between stability and course-keeping qualities (manoeuvrability).</p><p&g

93、t;　　The idea of vulnerability criteria, to be developed in two levels (vulnerability and severity) is of paramount importance in the frame of criteria aimed at improving ship safety and making safety improvement more “co

94、st-effective” against modes of failure not covered by present criteria. It could avoid the need for indiscriminate generalized application of heavy computational or experimental procedures (Bassler et al., 2009). It is

95、generally accepted that the new criteria will require calculatio</p><p>　　5. CONCLUSIONS </p><p>　　Looking into the scientific and regulatory developments in ship floatability and stability 23 c

96、enturies after Archimedes, it is trivial to say that develop-ments, introduced slowly, have been significant, thus greatly improving the safety of ships and the people and cargo onboard even in very harsh environmental c

97、onditions. Transportation by ship, especially of bulk cargo, remains the most efficient and environmental friendly mode of transport. The Archimedean principles of buoyancy and stabilit</p><p>　　Time scales

98、of most recent related developments (last two decades) were reduced drastically, owing to the fact that scientific approaches to ship safety came to maturity and expectations of society regarding mari-time safety are ext

99、remely high. </p><p>　　An evident new development in maritime regulatory matters, including those related to ship’s stability and subdivision, is the introduction of pro-active rather than reactive methods.

100、 This is entirely in the frame of so-called Formal Safety Assessment (FSA) procedures, in which safety regulations and properties (like ship stability) are assessed in terms of societal accept-ance criteria, eventually p

101、ostulating an acceptable number of fatalities for people onboard of ships per year. Related to FS</p><p>　　REFERENCES </p><p>　　Bassler, C., Belenky, V., Bulian, G., Francescutto, A., Spyrou, K.

102、 and Umeda, N. (2009), “A Review of Available Methods for Application to Second Level Vulnerability Criteria”, Proc. 10thInt. Conf. on Stability of Ships and Ocean Vehicles, A. B. Degtyarev Ed., Saint-Petersburg, pp. 111

103、–128. </p><p>　　Francescutto, A. (2007), “Intact Stability of Ships: Recent Developments and Trends”, Proc. 10thInt. Symp. on Practical Design of Ships and Other Floating Structures – PRADS’07, Houston, Vol

104、. 1, pp. 487–496. </p><p>　　Froude, W. (1861), “On the Rolling of Ships”, Trans. INA, Vol. 2, 1861, pp. 180–229. Girstmair, K., Kirchner, G. (2008), Towards a completion of Archimedes’ treatise on </p>

105、;<p>　　floating bodies, Expositiones Mathematicae, Vol. 26, pp. 219–236. GOALDS Project (2009–2012): “Goal-Based Damaged Stability”, European Commission, </p><p>　　FP7, DG Transport, Grant agreement n

106、o.: 233876, http://www.goalds.org.</p><p>　　IMO, SOLAS 95 - RESOLUTION 14 (1995), “Regional Agreement on specific stability requirements for Ro-Ro Passenger Ships”, incl. Appendix on Equivalent Model Test M

107、ethod, Resolution 14 of amended SOLAS 1974, adopted on 29 November 1995. </p><p>　　IMO, MSC.216(82), “Adoption of Amendments to the International Convention for the Safety of Life at Sea, 1974, As Amended”,

108、 adopted 8th December 2006 (SOLAS 2009). </p><p>　　Krylov, A (1898), A General Theory of the Oscillations of a Ship on Waves, Trans. INA, Vol. 40, pp. 135–196. </p><p>　　Nowacki, H., Archimedes