WorldWideScience

Sample records for catamarans

  1. The Local Transformation of the Catamaran-stern Hull

    Institute of Scientific and Technical Information of China (English)

    XU Na

    2016-01-01

    [Abstract]Lines plan of a ship related to resistance,structural strength,and economic benefit,is a complicated system engineering.Especially for the catamaran-stern hull,the designers have to modify the lines plan of the ship,in order to combine the catamaran-stern with the main ship hull.This paper use trigonometric function method to achieve the local transformation of catamaran-stern hull;on the other hand,making it programmed can effectively shorten the cycle of shipbuilding.

  2. Fuzzy robust attitude controller design for hydrofoil catamaran

    Institute of Scientific and Technical Information of China (English)

    Ren Junsheng; Yang Yansheng

    2005-01-01

    A robust attitude controller for hydrofoil catamaran throughout its operating envelope is proposed, based on Tagaki-Sugeno (T-S) fuzzy model. Firstly, T-S fuzzy model and robust attitude control strategy for hydrofoil catamaran is presented by use of linear matrix inequality (LMI) techniques. Secondly, a nonlinear mathematical model of hydrofoil catamaran is established, acting as the platform for further researches. The specialty in interpolation of T-S fuzzy model guarantees that feedback gain can be obtained smoothly, while boat's speed is shifting over the operating envelope. The external disturbances are also attenuated to achieve H∞ control performance, meanwhile. Finally, based on such a boat,HC200B-A1, simulation researches demonstrate the design procedures and the effectiveness of fuzzy robust attitude controller.

  3. Analysis of structural dynamic characteristics of a high speed light special catamaran

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper,structural dynamic characteristics of a high-speed light special catamaran-wave piercing catamaran are analyzed using the FEA software MSC-NASTRAN.The dynamic reduction method is introduced to eliminate the local vibration modes in order to obtain the whole ship's mode shapes.In the post-processor,a lot of accessorial methods are adopted to eliminate the local vibrations,so that the whole ship's mode shapes can be identified.The modal analysis indicates that the dynamic reduction method fits for mode shapes identifying.In the end,the test results of a catamaran named Frederick G.Greed are used for reference to validate the obtained results.The comparison process shows that the results are credible.A special mode shape,which is quite different with that of conventional monohull ship,is also pointed out.The obtained results provide a valuable reference for the coming computation of catamaran's vibration characteristics.

  4. The Low-Noise Potential of Distributed Propulsion on a Catamaran Aircraft

    Science.gov (United States)

    Posey, Joe W.; Tinetti, A. F.; Dunn, M. H.

    2006-01-01

    The noise shielding potential of an inboard-wing catamaran aircraft when coupled with distributed propulsion is examined. Here, only low-frequency jet noise from mid-wing-mounted engines is considered. Because low frequencies are the most difficult to shield, these calculations put a lower bound on the potential shielding benefit. In this proof-of-concept study, simple physical models are used to describe the 3-D scattering of jet noise by conceptualized catamaran aircraft. The Fast Scattering Code is used to predict noise levels on and about the aircraft. Shielding results are presented for several catamaran type geometries and simple noise source configurations representative of distributed propulsion radiation. Computational analyses are presented that demonstrate the shielding benefits of distributed propulsion and of increasing the width of the inboard wing. Also, sample calculations using the FSC are presented that demonstrate additional noise reduction on the aircraft fuselage by the use of acoustic liners on the inboard wing trailing edge. A full conceptual aircraft design would have to be analyzed over a complete mission to more accurately quantify community noise levels and aircraft performance, but the present shielding calculations show that a large acoustic benefit could be achieved by combining distributed propulsion and liner technology with a twin-fuselage planform.

  5. RANS SIMULATION OF HYDROFOIL EFFECTS ON HYDRODYNAMIC COEFFICIENTS OF A PLANING CATAMARAN

    Directory of Open Access Journals (Sweden)

    Amin Najafi

    2016-03-01

    Full Text Available Determination of high-speed crafts’ hydrodynamic coefficients will help to analyze the dynamics of these kinds of vessels and the factors affecting their dynamic stabilities. Also, it can be useful and effective in controlling the vessel instabilities. The main purpose of this study is to determine the coefficients of longitudinal motions of a planing catamaran with and without a hydrofoil using RANS method to evaluate the foil effects on them. Determination of hydrodynamic coefficients by experimental approach is costly, and requires meticulous laboratory equipment; therefore, utilizing numerical methods and developing a virtual laboratory seems highly efficient. In the present study, the numerical results for hydrodynamic coefficients of a high-speed craft are verified against Troesch’s (1992 experimental results. In the following, after determination of hydrodynamic coefficients of a planing catamaran with and without foil, the foil effects on its hydrodynamic coefficients are evaluated. The results indicate that most of the coefficients are frequency independent especially at high frequencies.

  6. DESAIN KAPAL IKAN DENGAN BENTUK LAMBUNG CATAMARAN YANG MENGGUNAKAN SISTEM PENGGERAK LAYAR AN MESIN UNTUK MUATAN IKAN HIDUP

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-02-01

    Full Text Available The Application Of Catamaran Hullform For The Fishing Vessel accorded to the leakage of the monohullform. The existence and the using of the lively fish hold could help the fisherman to decrease theoperational cost for about 11,8% to keep the fishes. Therefore the application of sail objected to reduce thebiggest cost operation component that is the fuel consumption. Catamaranhullform design for lively fish holdtook one hullform which has the best performance. The performance aspects in this case are the hydrostatic,ship resistance, stability and seakeeping.The research about catamaran fishing vessel design for lively fishes using sail and machine as the ship moveris expected to give the information about the hullform that has a better performance than the commonlyhullform and it could be an alternative to improve the fishing vessel hullform into the modern one.Accorded to the calculation result and analysis are gained the result that showed at the velocity of 12 knotsfrom some length dimension variations of fish hold for the catamaran fishing vessel with lively fish hold,variation of length of 2,0 meters could reduced the biggest ship’s resistance for about 3,99% between theother modification hullform and the ship’s resistance of standard hullform. Otherwise, by the stability aspectof any variation condition, fish hold length dimension variation at 2,0 meters had a better stability thananother fish hold length dimension and catamaran fishing vessel which used the commonly fish hold. Theinstallation of sail at the fish hold length dimension at 2,0 meters could reduce the power operation for about48,42% better than fishing vessel that used the commonly fish hold.

  7. Numerical estimation of interactions between foils and hulls of hydrofoil catamaran; Suichu yokutsuki sodosen no sentai to suichuyoku no sogo kansho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, K.; Ando, J.; Nakatake, K. [Kyushu University, Fukuoka (Japan)

    1998-09-04

    The hydrofoil catamaran model which is built up with the twin Wigley hulls and the tandem fore and aft set of hydrofoils is used for the numerical calculation and the experiments of this model was performed at Kyushu University. In this paper, combining with a Rankine source method, the SQCM (a simple panel method) is applied to the unsymmetrical flow problem around catamarans. And the running attitude of the model is not fixed in both the calculation and the experiments. Comparing with the experiment we show the interaction between hulls and the hydrofoils for the lift and the wave-making resistance in the high speed range. 6 refs., 11 figs.

  8. 高速复合水翼双体船的运动预报%Motion Prediction of a High-speed Hybrid Hydrofoil Catamaran

    Institute of Scientific and Technical Information of China (English)

    高成君; 赵峰; 赵发明; 王小川

    2009-01-01

    2.5D theory considering viscous effect for predicting the motion responses of the high-speed hybrid hydrofoil catamaran in regular wave is presented in this paper,and numerical predictions are compared with experimental results. Different ratios of lift and buoyancy are calculated. Compli-cated hydrofoils are replaced by simple foil models in calculation.It is found that the viscous effect can not be ignored in calculating longitudinal motion characteristics of high-speed catamaran and hy-brid hydrofoil catamaran.The results show that the present method can satisfactorily predict the mo-tion response characteristics, and can give improved motion prediction of high-speed hybrid hydrofoil catamaran.%基于2.5D理论,考虑粘性影响,预报了高速复合水翼双体船在规则波中的运动响应,并与试验结果进行了比较.在计算过程中,对复合水翼模型进行了简化,且计算了不同升力浮力比对运动的影响.结果反应出在计算高速双体船和水翼双体复合船型纵向运动性能时,水的粘性影响不可忽略,且计算表明计算值与试验值符合较好,文中提供的方法可提高这类高速水翼双体复合船型的运动预报精度.

  9. On the wave induced responses for a high-speed hydrofoil catamaran. Part 2. Cabin connected to hull by spring and response to vibration; Suichuyokutsuki kosoku sodotei no harochu oto ni tsuite. 2. Dokuritsu kozogata cabin to yodo oto

    Energy Technology Data Exchange (ETDEWEB)

    Nobukawa, H.; Kitamura, M.; Kawamura, T. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1996-04-10

    A high-speed hydrofoil catamaran under development has such a structure that an independent cabin is mounted on catamaran hulls, the cabin is connected with the hulls by using four soft springs, and hydrofoils are attached to the front and rear of the cabin. The structural design conception was as follows: the self-weight of the cabin is supported by lifting power of the hydrofoils while the boat is cruising; longitudinal motions of the catamaran hulls are absorbed by soft spring struts to make the motions more difficult to be transmitted into the cabin; and vibration excited by engines rotating at high speeds, attached to rear of the catamaran hulls, is not transmitted directly to the cabin structurally. A towing experiment was carried out by using divided models of about 1/10 scale in counter waves and regular waves to investigate their vibration response characteristics in waves. Furthermore, an experimental boat made of aluminum alloy with about 1/3 scale of the design boat was attached with composite structural struts made of springs and rubber parts to perform cruising experiments on an actual sea area. As a result, it was found that vibration excited by main engines in the catamaran hulls is transmitted very little to the cabin. 2 refs., 10 figs., 1 tab.

  10. Método dinamométrico para avaliação da escora em barcos tipo Catamaran Dynamometric method for the evaluation of hiking in Catamaran boats

    Directory of Open Access Journals (Sweden)

    Gustavo Ricardo Schütz

    2010-03-01

    Full Text Available Este estudo tem como objetivo propor e validar um método de medição da distância de escora ("De" e do momento de escora ("Me", através do uso de plataformas de força para barcos tipo Catamaran. O novo método propõe a medição por dinamometria, com o posicionamento de plataformas de força abaixo de cada casco, e a mensuração das Forças de Reação do Solo (FRS. Com base nas equações clássicas da estática são determinadas as variáveis "De" e "Me". Para validar o método proposto, foi utilizada a validação concorrente, através da comparação com os valores obtidos por cinemetria através do sistema "Peak Motus". Para correlação entre os dois métodos optou-se pelo coeficiente de correlação intraclasse (ICC. Foram analisadas diferentes posturas em duas diferentes inclinações do barco, simulando o adernamento do barco. Os resultados encontrados apontaram alta correlação (ICC > 0,99 e pequeno erro médio (1,00% para "De" e 0,96% para "Me" entre os métodos. Com isto, o método proposto se mostrou válido e eficiente, pois mensurou as variáveis de maneira rápida e precisa e se torna importante à medida que facilita a análise e auxilia a velejadores e técnicos na tomada de decisõesThis study aimed to propose and to validate a method for the measurement of hiking distance (Hd and hiking moment (Hm in Catamaran boats, through the use of force plates. This new method proposes the measurement by dynamometry, with the positioning of a force plate below each boat hoof to measure the Ground Reaction Forces (GRF. Based on the classic static equations Hd and Hm were determined. In order to validate the method a validation of competing was carried out through the comparison with kinematic values measured through the Peak Motus system. Intraclass correlation coeficient was used. Different positions in two different inclinations of the boat, simulating the boat heeling, had been analyzed. The results showed a high correlation

  11. Method for calculating wave resistance in a catamaran by using a simple panel method; Kanbenna panel ho ni yoru katamaran no zoha teiko keisanho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-10-01

    This paper describes a method for calculating wave resistance in a catamaran by using a simple panel method. Two Wigley models were put side by side to make a catamaran, speccular images were taken on a face symmetrical in the left and right sides, and only one side (the demi-hull) was used as a region to be calculated. Considering blow-out onto the demi-hull surface and still water surface, a model was constituted, in which discrete vortices were distributed on the demi-hull camber to flow the vortices out to an infinitely distance place from the stern. A free surface condition according to double model linearization by Dawson was derived for this model in terms of numerical analysis. The Kutta`s condition is incorporated when SQCM is used concurrently with the Rankine source method, but not incorporated when not used. Calculations were performed on both conditions. Wave resistance was derived by using pressure integral on the hull surface. It is better to consider the Kutta`s condition when the distance between the demi-hulls is small. However, if the distance is large, or speed is great for the boat length resulting in less interference between the demi-hulls, there is very little difference due to the Kutta`s condition. Difference in the wave shapes causes how waves are made to vary. 11 refs., 8 figs.

  12. Voyage By Catamaran: Long-Distance Network Navigation, from Myth Logic to the Semantic Web, Can Be Effected by Infinite-Dimensional Zero-Divisor Ensembles

    CERN Document Server

    de Marrais, Robert P C

    2008-01-01

    Continuing arguments presented [1] or announced [2][3] in "Complex Systems," zero-divisor (ZD) foundations for "scale-free" networks are "decentralized": "Cowbird's Nests," one "exploded" from each box-kite, house copies of the (ZD-free) Octonions - the recursive basis for all ZD ensembles, making Nests potential waystations for alien-ensemble "infiltrators." ZD "representations" of Catastrophe Theory unfoldings engulf Jean Petitot's modeling agenda, consolidating separate analyses of Greimas's Semiotic Square [4] and Levi-Strauss's Canonical Law of Myths [5] in a unified "Semantic Webology." All of which is enabled by switching focus from the octahedral Box-Kite's triangular Sails, to its square Catamarans and their box-kite-switching "twist products."

  13. On the wave induced responses for a high-speed hydrofoil catamaran. Part 1. Cabin connected to hull by spring and its riding comfort in waves; Suichuyokutsuki kosoku sodotei no harochu oto ni tsuite. 1. Dokuritsu kozogata cabin to harochu norigokochi

    Energy Technology Data Exchange (ETDEWEB)

    Saito, K.; Nobukawa, H.; Honda, Y. [Hiroshima University, Hiroshima (Japan)

    1996-04-10

    Riding comfort in a cabin of a high-speed hydrofoil catamaran was evaluated by comparing with that in ordinary boats as to acceleration in the vertical direction as one of the responses of the catamaran in waves. First, an equation of motion in waves was introduced, and considerations were given while comparing the result of calculations in regular waves with that of model experiments. Comparison and verification were also performed on response characteristics in irregular waves. A new-type boat, whose cabin is supported with four springs, and provided with hydrofoils in front and rear thereof, was verified to have much less motions of the catamaran bodies and the cabin than in the ordinary boats both in regular and irregular waves. This result was proven by numerical calculations and model experiments. Hydrofoils affect largely the reduction in motions. The correlational data between the results of calculations and experiments are considered sufficient to provide design data, although there are still some points to be improved. These results revealed that the riding comfort of the new-type boat has been improved over that in the ordinary boats. 6 refs., 11 figs., 3 tabs.

  14. 一种高速双体船耐波性的快速预报方法%A Fast Seakeeping Prediction Method for a High Speed Catamaran Advancing in Waves

    Institute of Scientific and Technical Information of China (English)

    许勇; 董文才

    2014-01-01

    文章以三维面元法为基础,开发了一套求解高速双体船在波浪中运动时耐波性的预报程序。该程序以三维移动脉动源格林函数为边界积分方程的基本内核,并根据该函数的对称特性及双体船辐射-绕射波的基本传播特征,采用三种方法来改进耐波性预报时的计算效率。以两条刘易斯船组成的双体船为计算对象,采用该程序求解了该船的水动力及运动响应,并和试验结果及未改进方法的预报结果进行了比较。分析表明文中方法的预报结果和试验结果吻合良好,且预报精度和未改进方法预报精度相当,而计算效率可达到未改进方法的2.9~4倍。因此该程序可作为高速双体船耐波性快速预报的有效方法。%Based on the 3D surface panel method, a fast-calculating computer code is developed in the present study to predict seakeeping performances for a high speed catamaran advancing in waves. The 3D translating-pulsating source Green function is chosen as the kernel function for the boundary element integral equation. Three methods based on the symmetry of the Green function to-gether with performances of the radiation-diffraction waves are introduced in the code to improve the calculating efficiency. Validation is performed through studying hydrodynamic terms and free mo-tions of a twin Lewis-form hulls by comparing model tests or predictions of the exact method (the method without improvement). The predictions obtained by the present method show general agree-ment with the experiments and the accuracy can be kept almost the same as that obtained in the exact method. The calculating speed of the present method is about 2.9-4 times of that of the exact method in the case of CPU time test. The present solver may serve as a fast and valid tool to predict seakeeping performances of a high speed catamaran advancing at sea.

  15. Improvement of Longitudinal Motion Performance of High Speed Light Wave-Piercing Catamaran by Hydrofoils%高速轻型穿浪双体船纵向运动改善措施研究

    Institute of Scientific and Technical Information of China (English)

    郑义; 董文才

    2012-01-01

    The pitch and heave motion range of high speed light wave-piercing catamaran (WPC) in head sea would become much higher while wave length near the ship length. Theoretical approaches together with model test were induced to provide a longitudinal motion performance improvement for a 250 t WPC using hydrofoils. The influence of the hydrofoils parameters, such as the shape, size and mounting locations, were investigated. A comparison of numerical calculation results and test data suggests that the strip method, with hydrodynamic interactions between hydrofoil and the hull taken into account, is applicable to the longitudinal motion prediction of WPC with hydrofoils, though the calculated RAO is a little bigger which near the RAO peak value. Based on the model test data, the significant amplitude of heave and pitch of the tested model in head sea reduced 20%~30% with the hydrofoils installed.%针对在改善高速轻型穿浪双体船(WPC)迎浪中波长与船长接近时纵向运动幅度较大的缺点,采用了理论计算与模型试验相结合的方法,对250t级穿浪双体船开展了水翼改善纵向运动的理论和试验研究,分析了水翼形式、尺度和安装位置等对纵向运动的影响规律.数值计算和试验结果的比较表明,计及水翼-船体水动力干扰影响的切片理论可满足WPC加水翼后波浪中纵向运动计算的需要,但在纵向运动响应峰值处数值计算结果偏高.模型试验表明,250 t级WPC加装水翼后,迎浪纵摇和垂荡有义幅值可减少20%~30%.

  16. Experimental Investigation of Catamaran Cross-Structure Slamming

    Science.gov (United States)

    1975-09-01

    to Investigate the Three-Dimensional Effects of Slamming," NSRDC Report 3543 (Apr 1971). 8 i Carnahan, B. et al., " Applied Numerical Methods ," Chapter...Tests of Cones to Investigate the Three-Dimensional Effects of Slamming," NSRDC Report 3543 (Apr 1971) 8. Carnahan, B. et al., " Applied Numerical Methods ," Chapter

  17. Improving the Efficiency of a High Speed Catamaran Through the Replacement of the Propulsion System

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2015-12-01

    Full Text Available The high speed vessels are primarily designed for short distances services as public transport of passengers and vehicles. The range of high speed, according to the Code of high-speed vessels begins at 20 knots, which depends on the cruise speed you desire for your vessel; you will have to use the most appropriate type of propellant. In general, in the past 20 years, they have been building high-speed vessels with speeds above 33 knots, which meant installing water jet propellants coupled to powerful engines and therefore of high consumption of fuel, increasing operating costs and causing increased air pollution. Although the prices of fuel have been reduced to half, due to the sharp fall in oil prices, the consumption of fuel and the air pollution remains high at these speeds and powers used, in addition to that the reduction of the time spent on each trip is not excessive, mainly in short routes that are less than an hour . This article is about adapting a ship of high-speed service, with a maximum speed in tests of 34 knots and to reduce its operating costs (fuel, maintenance, etc. and make it economically viable; before the transformation, this vessel was operating with a service speed of 22 knots, and with a consumption per mile of 135 litters of MGO. The transformation process has consisted by: – Replacement of the two original water jet with four shaft lines with fix pitch propeller. – Replacement of the two original main engines (2 x 6500 kW = 13000 kW by four engines (4 x 1380kW = 5.520 kW. – Changing the underwater hull shape to fit the new propellers and maximize its efficiency. – Relocation of auxiliary engines, to achieve the most efficient trim. – Installation of two lateral propellers to improve maneuverability and shorten the total time of journey. After the reform and the return to service of the vessel with a service speed of over 22 knots, it has been verified that the consumption per mile is of 45 litters MGO, representing a reduction of 65% of consumption and even more reduction of emissions as the new engines comply with the latest regulations.

  18. Voyage by Catamaran: Effecting Semantic Network "Bricolage" via Infinite-Dimensional Zero-Divisor Ensembles

    OpenAIRE

    de Marrais, Robert P. C.

    2008-01-01

    Continuing arguments presented [1] or announced [2][3] in "Complex Systems," zero-divisor (ZD) foundations for "scale-free" networks (evinced, in particular, in the "fractality" of the Internet) are decentralized. Spandrels, quartets of ZD-free or "hidden" box-kite-like structures (HBKs) in the 2^(N+1)- ions, are "exploded" from (and uniquely linked to) each standard box-kite in the 2^N-ions, N > 3. Any HBK houses, in a "cowbird's nest," exactly one copy of the (ZD-free) octonions, the recurs...

  19. ANALISA KOMPONEN HAMBATAN KAPAL IKAN TRADISIONAL DI PERAIRAN CILACAP

    Directory of Open Access Journals (Sweden)

    Samuel Samuel

    2016-03-01

    Full Text Available RESISTANCE COMPONENT ANALYSIS OF TRADITIONAL FISHING BOAT IN CILACAPMonohull fishing boats used to catch fish is modified into a catamaran boat. The purpose of this modification is to get more fish. Catamaran ship has a double hull, but with the double hull ships resulted in increasingly complex resistances. It is interesting to study in depth about the resistance components of Catamaran boat. Resistance Components not only consist of surge resistance, frictional resistance, and the form resistance but with the distance between demihull causing interference waves. There are many research results of Catamaran boat in that aspect, but the data and information obtained from the experiment is still inadequate. In addition, there is still lack of accuracy particularly in predicting interference resistance component in calm water (calm-water resistance as a result of the distance between the demihull. This study aims to describe the resistance component at Catamaran boat by using slender body method. Keywords: catamaran, Cilacap, slender body method ABSTRAK Kapal ikan monohull yang biasa digunakan untuk mencari ikan dimodifikasi menjadi kapal catamaran. Tujuan modifikasi ini untuk mendapatkan muatan ikan yang lebih banyak. Kapal Catamaran mempunyai dua lambung, tetapi dengan adanya dua lambung mengakibatkan hambatan kapal semakin kompleks. Menarik untuk dikaji lebih lanjut tentang komponen hambatan kapal Catamaran. Komponen hambatan tidak hanya terdiri dari hambatan gelombang, hambatan gesek, dan hambatan bentuk namun dengan adanya jarak antar demihull sehingga menimbulkan interferensi gelombang. Sudah banyak dijumpai hasil riset kapal Catamaran pada aspek tersebut, tetapi data dan informasi yang diperoleh dari eksperimen masih kurang memadai. Disamping itu, masih ditemukan ketidak-akurasian khususnya dalam memprediksi interferensi komponen hambatan pada air tenang (calm-water resistance akibat dari adanya jarak antar demihull tersebut. Penelitian

  20. 77 FR 10802 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel SILVER MOON; Invitation for...

    Science.gov (United States)

    2012-02-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Maritime Administration Requested Administrative Waiver of the Coastwise Trade Laws: Vessel SILVER MOON... the vessel SILVER MOON is: Intended Commercial Use of Vessel: ``Catamaran Sailing Charters, both...

  1. Cost Earnings Data 2001 - American Samoa Longline

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2001, 25 vessels > 50 feet in overall length joined the American Samoa longline fleet, which previously had consisted of local, small catamaran-style vessels...

  2. Optimal Selection of Floating Platform for Tidal Current Power Station

    Directory of Open Access Journals (Sweden)

    Fengmei Jing

    2013-06-01

    Full Text Available With continuous development of marine engineering, more and more new structures are used in the exploring of tidal current energy. Three are there different kinds of support structures for tidal current power station, which are sea-bed mounted/gravity based system, pile mounted system and floating moored platform. Comparison with them, the floating mooring system is suit for deep water and the application of which will be widely. In this study, catamaran and semi-submersible as floating platform of tidal current power station are studied. And they are compared with its economic, efficiency of turbine and stability of station. It is found that the catamaran is optimal choice. Based on basic ship theory and using software MOSES, the stability of Catamaran tidal current power station is also calculated. The research of this study is significant and it will be as the reference for the future study.

  3. Seacoaster advanced marine vehicle. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Burg, D.

    1998-08-18

    The Seacoaster combines the high efficiencies of Surface Effect Ships (SES) with simple catamaran hull construction. It has blower pressurized air cushions that support some 80-90 percent of displacement and hence the high efficiencies. However, unlike the SES, there are no expensive and high maintenance flexible seals. Each catamaran sidehull has a simple recess molded or built into its underside. Powered blowers direct pressurized air into such recesses and thereby create lifting air cushions. There are no flexible seals of any kind and there is no air cushion between the sidehulls. Extensive towed model tests were conducted that showed the viability of the invention.

  4. AMD183穿浪双体客船

    Institute of Scientific and Technical Information of China (English)

    唐志祥; 徐文珊

    2000-01-01

    This paper firstly analyzed the hi-speed passenger ship market along the coastal lines in Fujian Province in brief and then made detailed introductions to the prototype AMD 183 hi-speed wavepiecing catamaran on its hull structure, superstructure and marine equipment etc.

  5. X-joints in composite sandwich panels

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Janssen, G.Th.M.

    1998-01-01

    The small structural weight of fast large ships such as fast mono hulls or catamaran type of ships is of extreme importance to their success. One possible light weight structural solution is the sandwich panel with fibre reinforced laminates and a balsa, honeycomb or foam core. A severe obstacle for

  6. WAVESTRIDER Hullform Evaluation

    Science.gov (United States)

    1989-12-01

    physical injury such as the lower leg fractures which 1 TWIN HULL (CATAMARAN-LIKE) CRAFT SUPERCRITICAL PLANING TWO-STEPPED HULL IHYDROFOIL/PLANING PLATES...speed, the waterjet encountered cavitation 59 problems in developing sufficient thrust, and at high speed its lower efficiency demanded higher

  7. Direct Adaptive Rejection of Vortex-Induced Disturbances for a Powered SPAR Platform

    Science.gov (United States)

    VanZwieten, Tannen S.; Balas, Mark J.; VanZwieten, James H.; Driscoll, Frederick R.

    2009-01-01

    The Rapidly Deployable Stable Platform (RDSP) is a novel vessel designed to be a reconfigurable, stable at-sea platform. It consists of a detachable catamaran and spar, performing missions with the spar extending vertically below the catamaran and hoisting it completely out of the water. Multiple thrusters located along the spar allow it to be actively controlled in this configuration. A controller is presented in this work that uses an adaptive feedback algorithm in conjunction with Direct Adaptive Disturbance Rejection (DADR) to mitigate persistent, vortex-induced disturbances. Given the frequency of a disturbance, the nominal DADR scheme adaptively compensates for its unknown amplitude and phase. This algorithm is extended to adapt to a disturbance frequency that is only coarsely known by including a Phase Locked Loop (PLL). The PLL improves the frequency estimate on-line, allowing the modified controller to reduce vortex-induced motions by more than 95% using achievable thrust inputs.

  8. Experimental Study on Hysucat Vessels

    Institute of Scientific and Technical Information of China (English)

    M.S.Seif; M.Askari

    2004-01-01

    The paper contains the results of an experimental study on a planing catamaran. The aim of this study is resistance reduction with application of foils. Experiments are performed in different conditions and the results are compared with each other. The foils are used in different configurations and it is concluded that unsuitable design may result in larger resistance. But, it is also shown that, for a good design, the resistance may be reduced considerably.

  9. Is the change of heart in matters of energy consumption a twinaround towards solar energy Ecological innovations and natural science education. Documentation on a technical meeting. Energiewende = Sonnenwende Oekologische Innovationen und naturwissenschaftliche Bildung. Dokumentation einer Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, A.; Staeudel, L. (comps.)

    1998-01-01

    The compiled facts and examples are evidence that education itself is already heading for a kind of ''solar turnaround''. Under the aspects of ecological innovation and natural science education, the conference volume documents, inter alia, the following lectures given and workshops held: the energy policy of federal Germany; Greenpeace's solar campaign with reference to the solar energy school project; construction of a solar catamaran; and small and big energy projects realized at schools. (GL)

  10. Dynamics of Sandwaves under Combined Wave - Current Forcing and Mine Burial Processes, and Instrumentation for Measuring Nearshore Morphologic Change and Hydrodynamic Forcing

    Science.gov (United States)

    2012-09-30

    were conducted with a small boat with an ADCP, and motorized kayak with sidescan, echosounder and post-processing kinetic (PPK) GPS system and a REMUS...the motorized kayak shipboard bathymetry and sidescan surveys to document the spatial variability of the bedform field. This system produced...structure and grain size Tidally Resolving, Spring and Neap Surveys CATYAK (Catamaran Kayak ) SURVEY: Sidescan, Echosounder and PPK phase resolving

  11. COMPARISON OF RESISTANCE FOR SEVERAL DISPLACEMENT HIGH PERFORMANCE VEHICLES

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-ping; LI Yun; DONG Zu-shun

    2005-01-01

    According to the linear wave resistance theory, a comparison among the ship resistance for the high speed round bilge ships, the deep "Vee" vessels, the wave-piercing catamarans, and the high speed trimarans was given by using the high-speed round-bilge ship as a benchmark. And the optimal speed range of each ship form was also suggested by using the analysis of the research results.

  12. A Comparative Life Cycle Assessment of Conventional and All-Electric Car Ferries

    OpenAIRE

    Kullmann, Annelise B

    2016-01-01

    Abstract Increased environmental focus in the marine transport sector, and especially focus on its effect on global warming, have initiated the deployment of all-electric propulsion. This thesis quantifies the environmental impacts of four ferry alternatives using the method of life cycle assessment (LCA). An all-electric lightweight catamaran in aluminium is compared to a conventional diesel powered monohull in steel. In addition, two theoretical cases are included where the design is the...

  13. Joint Conference on Marine Safety and Environment/Ship Production (1st), held 1-5 June 1992

    Science.gov (United States)

    1992-06-05

    was too expensive; * the use of the paint was ineffective. By doing the inventarization himself, the company-leader became sensible to look at...werken op het visdek en bij de vangstverwerking. Fase 1 en faee 2. Technische Universiteit Delft Nat C. van der, B. van Harlen and J. Klein Woud, 1992 The...drastically influence the payload. As the speed of a SES is even more sensible to displacement varia- tions than a catamaran, this aspect needs careful

  14. A Quantitative Methodology for Mapping Project Costs to Engineering Decisions in Naval Ship Design and Procurement

    Science.gov (United States)

    2010-06-01

    Table 4-3 Material Yield Strength Material Yield Strength (TSI) Mild Steel 16.51786 High Strength Steel 20.98214 HY80 29.01786 Aluminum 5454 7.14286...mild steel to Eglass / Kevlar sandwich. In order to come up with an adequate input for the ANN, instead of documenting cost changes based on a...Values Parameter Monohull Catamaran Structural Material Type Mild Steel Mild Steel Ship Armament Minimum Military Minimum Military Ship Beam 60 Feet 90

  15. Dynamic characteristics of a WPC-comparison of transfer matrix method and FE method

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-long; NIE Wu

    2003-01-01

    To find the difference in dynamic characteristics between conventional monohull ship and wave penetrating catamaran (WPC), a WPC was taken as an object; its dynamic characteristics were computed by transfer matrix method and finite element method respectively. According to the comparison of the nature frequency results and mode shape results, the fact that FEM method is more suitable to dynamic characteristics analysis of a WPC was pointed out, special features on dynamic characteristics of WPC were given, and some beneficial suggestions are proposed to optimize the strength of a WPC in design period.

  16. Developments in skirt systems for air cushion vehicles

    Science.gov (United States)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  17. Yachting Club

    CERN Multimedia

    Yachting Club

    2012-01-01

    Under a cloudless sky, the YCC ran its traditional Traversée du Lac for dinghies and catamarans last Sunday. The turn-out was not good, surprisingly: do we all take longer or more frequent holidays than your Committee anticipated? Never mind, we had a final fleet of six, even with no catamarans: three Laser 1’s (now that is a popular boat and surely a wise recent purchase for the Club), and three RS’s, respectively 400, 500 and 800 (private). Winds were light, but even with a slightly delayed start, they were strong enough for Race Officer Tom Wilkins and ResQ driver Tim Hancox to fit in two complete circuits/races. In older times, that would have been one race of two circuits, but the scoring is fairer if you get a chance to recover your first start in a second heat! Adjacent is a photo (thank you Loic Le Canderff, also doing important work on ResQ) of one of the final winners, Sandrine on Laser 1, joint first with overall regatta coordinator, Sanja: yes, surprisingly, th...

  18. Yachting club

    CERN Multimedia

    Yachting club

    2011-01-01

    WARNING: your C key is about to expire... Good, we hoped that would draw your attention! A gentle reminder that, following the purchase of our fast, sophisticated racing catamaran Hobie Tiger Meerkat last season, your Committee decided to create a new key to reflect this, the EC (Experienced Catamaran). Those taking a C course will be assessed during a test as to whether they will gain the C key or the C plus EC key, so need only practise hard. Those - and we are many - who possess the C key from past years need to refresh our knowledge and prove our competence to sail Meerkat effectively with the EC key. This requires a few attested outings under good wind conditions, use of the gennaker, general control. And if it’s any consolation, we (remembering the Darts and then the Mysteres, and now both SL16 and Tiger) can confirm that she is really a pussycat, and really very willing to tack if you treat her right... Plan on trying for her or indeed Catapult on Thursdays, then talk to your Committee (f.i...

  19. Influence of a conservative sleep management strategy during a solo Pacific Ocean crossing on anxiety and perceived fatigue: a case study.

    Science.gov (United States)

    Hagin, Vincent; Gonzales, Benoît R; Candau, Robin B; Groslambert, Alain

    2012-01-01

    The aim of this case study was to determine whether a sailor's deliberate choice of a conservative strategy to manage sleep deprivation would allow him to cross the Pacific Ocean and to minimize his state of anxiety and perceived fatigue. The participant, who had more than 10 years' sailing experience in severe conditions, was tested on a small catamaran without any living quarters during a solo Pacific Ocean crossing. Estimations of sleep hours, state anxiety, and perceived fatigue were self-reported by the sailor on a daily basis using a specific questionnaire. The most important finding is that the sailor's deliberate sleep strategy, 5.4 h sleep per day (24% less than on-shore), was enough to keep his anxiety and perceived fatigue within acceptable limits and enabled him to achieve his goal, which was the first crossing of the Pacific Ocean on a catamaran of less than 6 m. In conclusion, our results suggest that the sailor observed in the present case study was able to minimize anxiety and perceived fatigue with adequate sleep to optimize his performance, security, and to achieve his goal.

  20. Damage Stability Assessment of an HSC after Grounding

    DEFF Research Database (Denmark)

    Ravn, Erik Sonne; Simonsen, Bo Cerup; Baatrup, Jan;

    2000-01-01

    Currently a substantial effort is done within the International Maritime Organisation (IMO) on revision of the High Speed Craft (HSC) Code. A main issue is the extent of bottom damage and raking damage due to grounding on hard rocks and the corresponding requirements to the damage stability...... of the vessel. It has been found that high-speed craft can experience a damage length up to 100% of the ship length. It has, however, also been argued that the damage stability requirements should reflect the size and probability of the damage with a reduction of the demand for the largest damages.......In the present paper a detailed grounding and damage stability analysis is carried out for two specific HSC, a mono-hull (86 m) and a catamaran (69 m). First various grounding scenarios are considered with different values of the forward speed and ground geometry. The results indicate that 100% bottom damage...

  1. Intersociety Advanced Marine Vehicles Conference and Exhibit, Arlington, VA, June 5-7, 1989, Technical Papers

    Science.gov (United States)

    The present conference on advanced marine vehicles discusses advancements in surface-effect ship (SES) technologies, small waterplane-area twin-hull (SWATH) ship operations, advanced marine vehicle concepts, ocean systems and subsurface vehicles, air-cushion vehicle (ACV) concepts, seaplane technologies, advanced hull hydrodynamics, wing-in-ground effect (WIGE) aircraft, competition-craft aerodynamics, and marine propulsion. Attention is given to military applications of the 'NES 200' SES platform, experiences over 16 years of SWATH ship operations, hydrofoil catamarans for military and civilian applications, SES passenger ferries for the N.Y.C. metropolitan area, advanced submarine concepts, parametric studies in SWATH ship design, ACV experience in Antarctica, the CL-215 seaplane, large-scale WIGE vehicles, an ocean spacecraft-launch facility, an ACV Arctic icebreaker, and 'marinizing' methods for gas turbine engines.

  2. WAVE MAKING COMPUTATION IN TIME DOMAIN FOR MULTI-HULL SHIPS

    Institute of Scientific and Technical Information of China (English)

    LI Guo-an; YE Heng-kui

    2006-01-01

    A method of three-dimensional time domain Green function satisfying linear conditions at free surface and body surface boundary was employed to analyze the wave resistance and wave profile of a displacement multi-hull ship. The wave profile induced by a moving time domain point source was compared with those by a Havelock source, and satisfactory results were obtained. The panel method based on the time domain source distribution on the ship mean wetted hull surface was used to perform the wave making com- putations for mono-hull ships, catamaran and trimaran. Reasonable results were also obtained. Using the numerical method the wave profile simulations of multi-hull ships for a given Froude number were conducted.

  3. Resistance and Seakeeping Numerical Performance Analyses of a Semi-Small Waterplane Area Twin Hull at Medium to High Speeds

    Institute of Scientific and Technical Information of China (English)

    Giuliano Vernengo; Dario Bruzzone

    2016-01-01

    The hydrodynamic analysis of a new semi-small waterplane area twin hull (SWATH) suitable for various applications such as small and medium size passenger ferries is presented. This may be an attractive crossover configuration resulting from the merging of two classical shapes: a conventional SWATH and a fast catamaran. The final hull design exhibits a wedge-like waterline shape with the maximum beam at the stern; the hull ends with a very narrow entrance angle, has a prominent bulbous bow typical of SWATH vessels, and features full stern to arrange waterjet propellers. Our analysis aims to perform a preliminary assessment of the hydrodynamic performance of a hull with such a complex shape both in terms of resistance of the hull in calm water and seakeeping capability in regular head waves and compare the performance with that of a conventional SWATH. The analysis is performed using a boundary element method that was preliminarily validated on a conventional SWATH vessel.

  4. Inland Rivers Floating Aids

    Science.gov (United States)

    2009-10-01

    1.4 1.5 2.25 9.25 4 NR USCG 470 Steel/Foam 5.0 1.4 1.5 2.25 10.44 CP-2800 - Catamaran India 508 GRP /Foam 8.0 0.0 0.0 0.82 9.19 FA-2013 Canada 350...Diameter (ft.) Length (ft.) FA-3007 0.3m, Ottawa Canada 152 Steel/Foam 0.0 1.1 2.5 1.17 7.66 FA-3008 Vari. Buoy. Canada 26 GRP /Foam 0.0 1.1 0.0 0.61...Each buoy is constructed of 3.5 lb/ft3 ionomer foam, similar to that of Gilman Corporation (Reference 18) wrapped around a steel center pipe

  5. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  6. 世界高速车客渡船的三大格局

    Institute of Scientific and Technical Information of China (English)

    徐菊英

    2000-01-01

    At the present, the ferries in different types have taken the majority for the shortdistance car/passenger transportation field in the world market. Furthermore, in the high-speed car/passenger ferries are seemed more attractive to the shipping companies. The existing high-speed car/passenger ferries in a fierce compelition are classified into 3 categories as catamaran high-speed ferries, monohull high-speed ferries and semi-SWATH high-speed ferries. In this paper, the author has analysed the successful reasons of the high-speed car/passenger ferries, described the main features of these ferries and also summerised the developing trend of these ferries in recent years.

  7. Multipurpose stabilization of the advanced marine surface crafts

    Directory of Open Access Journals (Sweden)

    Sevostyanov Ruslan A.

    2016-01-01

    Full Text Available Advanced marine surface crafts, such as SWATHs, catamarans or hovercrafts become more and more popular for a great range of various tasks. They usually operate at much higher speed than conventional ships. Moreover, in the open sea there are a lot of requirements and restrictions concerning the quality of such crafts’ dynamics, especially in case of the wind or waves. This paper considers application of the control law with a special multipurpose structure for autopilot design for amphibious air cushion vehicles. Such control law allows to decompose the autopilot task into simpler optimization subtasks. Efficiency of this approach is shown in the task of stabilizing yaw angle of the air cushion vehicle in the different weather conditions.

  8. A Floating Ocean Energy Conversion Device and Numerical Study on Buoy Shape and Performance

    Directory of Open Access Journals (Sweden)

    Ruiyin Song

    2016-05-01

    Full Text Available Wave and current energy can be harnessed in the East China Sea and South China Sea; however, both areas are subject to high frequencies of typhoon events. To improve the safety of the ocean energy conversion device, a Floating Ocean Energy Conversion Device (FOECD with a single mooring system is proposed, which can be towed to avoid severe ocean conditions or for regular maintenance. In this paper, the structure of the FOECD is introduced, and it includes a catamaran platform, an oscillating buoy part, a current turbine blade, hydraulic energy storage and an electrical generation part. The numerical study models the large catamaran platform as a single, large buoy, while the four floating buoys were modeled simply as small buoys. Theoretical models on wave energy power capture and efficiency were established. To improve the suitability of the buoy for use in the FOECD and its power harvesting capability, a numerical simulation of the four buoy geometries was undertaken. The shape profiles examined in this paper are cylindrical, turbinate (V-shaped and U-shaped cone with cylinder, and combined cylinder-hemisphere buoys. Simulation results reveal that the suitability of a turbinate buoy is the best of the four types. Further simulation models were carried out by adjusting the tip radius of the turbinate buoy. Three performance criteria including suitability, power harvesting capability and energy capture efficiency were analyzed. It reveals that the turbinate buoy has almost the same power harvesting capabilities and energy capture efficiency, while its suitability is far better than that of a cylindrical buoy.

  9. ANALISA FROUDE NUMBER EKONOMIS PADA KAPAL WISATA DI WADUK JATILUHUR DENGAN PENDEKATAN COMPUTATIONAL FLUID DYNAMIC (STUDI KASUS KM. JASATIRTA

    Directory of Open Access Journals (Sweden)

    Samuel Samuel

    2012-02-01

    Full Text Available Model catamarans increasingly popular as a means of transportation of goods and people that needdevelopment to find out more in the interaction prisoners on the ship hull in order to achieve stability and betterresistance. KM Jasatirta is one of ship model catamaran (double hull which is designed to support tourism inJatiluhur Reservoir. This study aims to find out more details interaction of the total prisoners in the ship's hullKM Jasatirta with Computational Fluid Dynamics approach.Research carried out several stages of manufacture of the Computational Fluid Dynamic model, simulationinput data, running simulations to converge, then analyzes the results of calculations by the methodSlenderBody, Delft Series, 98, and CFD. Analysis of the calculation includes the analysis of resistance, FroudeNumber economic , and comparative analysis of numerical calculation by the method of Computational FluidDynamics.The results of the analysis and calculation of reseach showed that the total ship resistance (Rt at 2 knots boatspeed by using the CFD method at 0.37 kN, Delft method Series'98 of 0.14 kN, while the calculation method forSlender Body 0.04 kN and a analityc calculation by the method of Millward's of 0215 kN. And based on theresults of analysis of Froude number of the most economical in terms of aspects of the ship's speed is the methodof Computational Fluid Dynamics with a value of 0094 sedangan Fn projection calculation with a quadraticfunction then the value of accurate Fn Series'98 Delft method so it can be used as a reference calculation.

  10. 船舶复合材料国外最新进展%The Foreign Latest Progress of Composite Materials for Ships

    Institute of Scientific and Technical Information of China (English)

    司卫华

    2011-01-01

    综述了船舶复合材料的前沿发展,面对增强塑料在船舶制造上的现有限制进行了分析,并提供了针对性的解决建议;介绍了"现代船舶建造中的碳纤维复合材料"领域的PlanetSolar的双体船项目,讨论了复合材料在船舶制造中的应用,作为现代制造业中的先进技术之一的复合材料的软件工具,及其对更多造船厂的视线吸引.同时对今后的发展进行了预测.%In this paper, the development of composite materials for ships was summarized. The limitation of reinforced plastics in shipbuilding was analyzed and the targeted solution proposal was supplied. The PlanetSolar project of catamarans using carbon fiber reinforced plastics (CFRP) in modern shipbuilding was introduced. The application of the composite materials in shipbuilding and the software tools for composite materials as one of the advanced technology in the modern manufacturing, were discussed. The vision attract to more shipyards was also commented. At the same time, the further development was predicted.

  11. Yachting Club

    CERN Multimedia

    Yachting Club

    2012-01-01

      Sailing course lottery Potential learners still have a couple of days to sign up to the Lottery for places in this season’s sailing courses. Yes, it is already quite heavily oversubscribed - as every year: we must run good courses! - but the draw is completely fair so you stand as good a chance as anyone else. Among questions we have been asked is which course is least oversubscribed - and might therefore offer a better chance of a place? Probably Surprise, since you ask, but then that is also one of the most demanding, both in terms of requisite keys you already need even to sign up in the Lottery and also likelihood of passing the test. Well, one was our most expensive boat purchase ever, and she is a boat that revels in being sailed well (even while being forgiving of the rest of us). The picture alongside is a loosely connected explanation to another question we get: how did catamaran Meerkat get named? We convinced ourselves that Meerkats are friendly, sociable, fast, intell...

  12. Estimation of performance of a high-speed boat by using the Rankine source method; Kosokutei no rankinsosuho ni yoru seino suitei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1997-10-01

    This paper describes estimation of performance of a high-speed boat by using the Rankine source method. An orthogonal coordinate system is considered, which uses the center of a hull as the zero point, and is made dimensionless by using the hull length. The catamaran boat or the single hull boat being the subject of the discussion is supposed to have a transom stern, and to be sailing at a constant speed in the -X direction. A governing equation and a border condition were formulated using disturbance speed potential and X-direction speed differentiation. An inverse specular image was employed as a specular image system upon considering attitude change in the high-speed boat. As to the division of hull surface, the portions protruded above the static water surface were cut off from among the panel data of boat CAD. Considering a high speed condition in which the water surface is completely separated at the transom section, the water level at the transom section was supposed to be at the same height as at the rear end of the hull. Blow-out intensity at the water surface was derived in such a way that a CAD panel of the rear end of the hull is searched and wave height agrees with the height of the transom in the Z direction. A resistance curve may be obtained easily by using a personal computer. 4 refs., 8 figs.

  13. Summary of the papers of the 95th Meeting of the West Japan Society of Naval Architects. Joint meeting of three shipbuilding societies in fall, fiscal 1997; Seibu Zosenkai dai 95 kai reikai ronbun gaiko. 1997 nendo shuki zosen sangakkai rengo koenkai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The paper summarized the papers on the following: estimation of the propulsion performance by the surface vortex lattice method using model ship flow field data; wave-making resistance calculation and performance estimation by the Rankine source method; calculation method of wave-making resistance of Catamaran and solution method of the hydrofoil problem using the convenient panel method; study of estimation of hydrodynamic forces acting on ship in maneuvering motion; study of the combined plant using generator use diesel exhaust heat; mathematical structure of the ocean container transport system; developmental OTEC plants in Indonesia. In relation to structural dynamics/strength problems, reports were made on the hull longitudinal strength theory, FEM modeling in analyses of buckling/plasticity collapse of deflection panels, etc. Further reported were a consideration of the use classification of hull use steel sheets considering fracture toughness, and changes of aspect ratios of small surface cracks emanating from a toe of corner boxing. Concerning ocean structures, there are experimental studies on vibration in water of a semi-spherical shell fixed in water, and a behavior of huge floating structures in regular waves

  14. YACHTING CLUB

    CERN Multimedia

    YACHTING CLUB

    2010-01-01

    INTERNAL RAGATTE - BEST EVER ! If you missed Internal Regatta III on Sunday 11 July, you missed one of the best we can recall! The winds were about perfect, fairly stable Bf 2 with periodic gusts higher and the resulting capsizes to keep crews concentrating. It was extremely hot but we ran the usual three heats for keelboats and a record four for dinghies, catamarans - where there was another record, surely: a total of 11 boats in that class, of which three privately owned by members. And a final record: we calculate five boats were competing in their first-ever regatta. Results on the webpage. Surprisingly for those who remember regattas of a couple of years back, only three keelboats competed, so there would have been plenty of scope for less experienced members to come along regardless and probably find themselves a place. It is also noteworthy that the keelboat winner was Andrea Messina with an - ummm, may I say - less experienced crew himself! We hope this win bodes well for his forthcoming Transl&am...

  15. A Unified Computational Method for Simulating Dynamic Behavior of Planing Vessels

    Institute of Scientific and Technical Information of China (English)

    Mohammad Saeed SEIF; Ebrahim JAHANBAKHSH; Roozbeh PANAHI; Mohammad Hossein KARIMI

    2009-01-01

    High speed planing hulls have complex hydrodynamic behaviors. The trim angle and drafts are very sensitive to speed and location of the center of gravity. Therefore, motion simulation for such vessels needs a strong coupling between rigid body motions and hydrodynamic analysis. In addition, free surface shoald be predicted with good accuracy for each time step. In this paper, velocity and pressure fields are coupled by use of the fractional step method. On the basis of in- tegration of the two-phase viscous flow induced stresses over the hull, acting loads (forces and moments) are calculated. With the strategy of boundary-fitted body-attached mesh and calculation of 6-DoF motions in each time step, time history of ship motions including displacements, speeds and accelerations are evaluated. For the demonstration of the software capabilities, circular cylinder slamming is simulated as a simple type of water slamming. Then, a high-speed planing catamaran is investigated in the case of steady forward motion. All of the results are in good concordance with experimen-tal data. The present toothed can be widely implemented in design as well as in the performance prediction of high-speed vessels.

  16. High Resolution Marine Magnetic Survey of Shallow Water Littoral Area

    Directory of Open Access Journals (Sweden)

    Jacob Sharvit

    2007-09-01

    Full Text Available The purpose of this paper is to present a system developed for detection andaccurate mapping of ferro-metallic objects buried below the seabed in shallow waters. Thesystem comprises a precise magnetic gradiometer and navigation subsystem, both installedon a non-magnetic catamaran towed by a low-magnetic interfering boat. In addition wepresent the results of a marine survey of a near-shore area in the vicinity of Atlit, a townsituated on the Mediterranean coast of Israel, about 15 km south of Haifa. The primarypurpose of the survey was to search for a Harvard airplane that crashed into the sea in 1960.A magnetic map of the survey area (3.5 km2 on a 0.5 m grid was created revealing theanomalies at sub-meter accuracy. For each investigated target location a correspondingferro-metallic item was dug out, one of which turned to be very similar to a part of thecrashed airplane. The accuracy of location was confirmed by matching the position of theactual dug artifacts with the magnetic map within a range of ± 1 m, in a water depth of 9 m.

  17. YACHTING CLUB

    CERN Multimedia

    Yachting Club

    2010-01-01

    TRAVERSEE DU LAC MEETS BOL D’OR It is not entire coincidence that your ever-attentive YCC Committee schedules our Traversée du Lac (dinghies, catamarans, windsurfs - although admittedly not many of the latter these last few seasons) for the same weekend as the rather larger-scale Bol d’Or: it enables our intrepid crews to practise their priority rules as Dona Bertarelli sweeps past with LadyCat and gives you something to watch should the wind drop momentarily ... The rest is history, as we say and your scribe will not repeat here the results, either of the Traversée or of the Bol - go find them on our respective Webs! But many thanks to John and Sarah Fullerton for organising this event and to Wolfgang Adam for ably skippering our new Q-boat. And a gentle reminder to us all, please, that we are fairly short of volunteers on all fronts: not merely routine maintenance, remembering to clean the boat you enjoy from time to time but also - urgently - Q-boat skippers (she&...

  18. CERN Yachting club

    CERN Document Server

    CERN Yachting club

    2015-01-01

    Surely among the most active sports clubs within CERN, the Yachting Club has had a steadily increasing membership over a decade; it is now around 350 but new members are always welcome, especially now at the beginning of a season. Indeed, with the Lottery for places in courses which are one of our highlights, membership has jumped since mid-March. The Lottery is always heavily oversubscribed, which we like to think represents its good reputation for quality of teaching and good fun at the same time. Now those lucky new students are in contact with their teachers, will be buying wetsuits in some cases (dinghy and catamaran courses), joining us for the launch of the fleet (see calendar on website at http://yachting.web.cern.ch/yachting/ycc_home.html ) and  – in many cases – learning sailing as complete beginners. Those Lottery-unlucky can still plan a fun season, with our Thursday Practice evenings, where we can almost always place everyone on a boat for an outing.   ...

  19. A one-dimensional polynomial chaos method in CFD-Based uncertainty quanti-fication for ship hydrodynamic performance

    Institute of Scientific and Technical Information of China (English)

    贺伟; 邹早建

    2013-01-01

    A one-dimensional non-intrusive Polynomial Chaos (PC) method is applied in Uncertainty Quantification (UQ) studies for CFD-based ship performances simulations. The uncertainty properties of Expected Value (EV) and Standard Deviation (SD) are evaluated by solving the PC coefficients from a linear system of algebraic equations. The one-dimensional PC with the Legendre polynomials is applied to:(1) stochastic input domain and (2) Cumulative Distribution Function (CDF) image domain, allowing for more flexibility. The PC method is validated with the Monte-Carlo benchmark results in several high-fidelity, CFD-based, ship UQ problems, evaluating the geometrical, operational and environmental uncertainties for the Delft Catamaran 372. Convergence is studied versus PC order P for both EV and SD, showing that high order PC is not necessary for present applications. Comparison is carried out for PC with/without the least square minimization when solving the PC coefficients. The least square minimization, using larger number of CFD samples, is recommended for current test cases. The study shows the potentials of PC method in Robust Design Optimization (RDO) and Reliability-Based Design Optimization (RBDO) of ship hydrodynamic performances.

  20. The U.S. Imperial Jugger-not: Saturation Points and Cultural Globalization

    Directory of Open Access Journals (Sweden)

    Meg Spohn Bertoni

    2010-03-01

    Full Text Available Globalization is not merely inevitable western cultural conquest. The assumption that the juggernaut of western hegemonic domination will continue until the world is consumed is a common one, but not an accurate one. That accuracy is compromised by a number of related misconceptions about the nature of globalization. Some of these have to do with an attachment to dichotomy in a world too complex for dualism. Some of them are related to assumptions about the nature of trade, of trends, of inevitability, and of statistical prediction that turn out not to be accurate—and by extension misconceptions about the unidirectionality of cultural exchange. Most are related to misconceptions about the nature of culture—particularly in oversimplifying, and making strange assumptions about, nonwestern cultures. Cultures change over time, with generations and historical forces—today’s cultural changes make up tomorrow’s cohesive culture. Cultures die not when they change to reflect the new attitudes and lifestyles of the peoples who live in them, but when they stagnate and become static, preserved only in museums, artifacts and books, and not in the everyday lives of the people themselves. Finally, phenomena do reach a saturation point, from biological populations to the motion of catamarans to absorption of cultural values, and these can be observed using methods of nonlinear dynamics. This project considers common misconceptions about globalization and culture, and uses concepts from nonlinear dynamics to expose the nature of the movement and saturation points of cultural globalization.

  1. 35 m豪华观光游览船设计%Design of 35 m Luxury Sightseeing Boat

    Institute of Scientific and Technical Information of China (English)

    李炎锋

    2014-01-01

    本文介绍一艘低速、游艇型的双体客船设计,叙述了该船为满足城市观光、游览、商务接待等使用要求而进行的设计,让读者了解该船型如何匹配城市风光和建筑特点,使一艘船能起到城市推介的媒体和平台的作用,突出旅游观光船成为城市代名片的设计理念。%The article presents a low-speed, type of passenger catamaran yacht design. Describing the special design for the vessel which meets requirements of city tours and excursions, as well as official reception, the paper is aimed at leading readers to understand how a boat can match the city landscape and architectural characteristics, so that it can recommend the city as a media and platform, projecting the design points that makes sightseeing boat into a city-generation business card.

  2. 92nd Meeting of West Japan Society of Naval Architects. Summary of papers; Seibu zosenkai dai 92 kai reikai. Ronbun kogai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-10

    The 92nd Meeting of West Japan Society of Naval Architects was held at Shimonoseki city on May 9 and 10, 1996, and 27 papers were made public. As for hydrodynamic force, the following were reported: Hydrodynamic interference between hull and submerged foils; An experimental research on maneuvering hydrodynamic force interference coefficients; A research on the method to estimate maneuvering hydrodynamic force at swirl motion; An experimental research on the method to estimate hydrodynamic force added to floating offshore structures, etc. As to the high-speed hydrofoil catamaran, Cabin connected to hull by spring and its riding comfort in waves, and Cabin connected to hull and vibration response. Relating to fundamental experiments, An experiment on vibration in water of the cylinder shell fixed in water; An research on fracture behavior of rectangular waves under water pressure; Buckling of the continuous stiffened plate under in-plane compressive loads; An research on plasticity decay behavior, etc. In addition, The aesthetics of ship design and the dynamic symmetry; Spilt oil pollution preventive measures and effects of the ocean preservation, etc.

  3. New approaches to the design optimization of hydrofoils

    Science.gov (United States)

    Beyhaghi, Pooriya; Meneghello, Gianluca; Bewley, Thomas

    2015-11-01

    Two simulation-based approaches are developed to optimize the design of hydrofoils for foiling catamarans, with the objective of maximizing efficiency (lift/drag). In the first, a simple hydrofoil model based on the vortex-lattice method is coupled with a hybrid global and local optimization algorithm that combines our Delaunay-based optimization algorithm with a Generalized Pattern Search. This optimization procedure is compared with the classical Newton-based optimization method. The accuracy of the vortex-lattice simulation of the optimized design is compared with a more accurate and computationally expensive LES-based simulation. In the second approach, the (expensive) LES model of the flow is used directly during the optimization. A modified Delaunay-based optimization algorithm is used to maximize the efficiency of the optimization, which measures a finite-time averaged approximation of the infinite-time averaged value of an ergodic and stationary process. Since the optimization algorithm takes into account the uncertainty of the finite-time averaged approximation of the infinite-time averaged statistic of interest, the total computational time of the optimization algorithm is significantly reduced. Results from the two different approaches are compared.

  4. Retrospective assessment of macrophytic communities in southern Lake Garda (Italy from in situ and MIVIS (Multispectral Infrared and Visible Imaging Spectrometer data

    Directory of Open Access Journals (Sweden)

    Claudia Giardino

    2012-01-01

    Full Text Available In situ and hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer images acquired over a period of 13 years are used to assess changes in macrophyte colonization patterns in the coastal zones of the Sirmione Peninsula in the southern part of Lake Garda (Italy. In situ data (abundance, cover density and diversity of macrophyte communities and MIVIS-derived maps of colonized substrates are analyzed by considering the variability of the main hydrological and physicochemical variables in order to indicate the main factors that explain the spatiotemporal variability of macrophyte communities. The results show a considerable modification in terms of macrophyte structural complexity and colonized areas. Almost 98% of macrophyte meadows (in particular communities with a density of over 70% are lost and subsequently replaced by moderate to extremely rare communities with density from 10% to 40%. Well-established submerged macrophytes are replaced by de-structured communities characterized by moderate to scarce density: on average lower than 30%. The study indicates that macrophyte distribution along the littoral zone of the Sirmione Peninsula is certainly linked to water transparency and water level fluctuation. The results also indicate that the worsening of eutrophication may be associated with the gradual disappearance of macrophyte meadows, but may also be accelerated by herbivorous aquatic birds grazing there. Lastly, the increasing frequency and number of catamaran tours could be considered a threat for the stability of these valuable communities.

  5. Intelligent Control for USV Based on Improved Elman Neural Network with TSK Fuzzy

    Directory of Open Access Journals (Sweden)

    Shang-Jen Chuang

    2014-01-01

    Full Text Available In recent years, based on the rising of global personal safety demand and human resource cost considerations, development of unmanned vehicles to replace manpower requirement to perform high-risk operations is increasing. In order to acquire useful resources under the marine environment, a large boat as an unmanned surface vehicle (USV was implemented. The USV is equipped with automatic navigation features and a complete substitute artificial manipulation. This USV system for exploring the marine environment has more carrying capacity and that measurement system can also be self-designed through a modular approach in accordance with the needs for various types of environmental conditions. The investigation work becomes more flexible. A catamaran hull is adopted as automatic navigation test with CompactRIO embedded system. Through GPS and direction sensor we not only can know the current location of the boat, but also can calculate the distance with a predetermined position and the angle difference immediately. In this paper, the design of automatic navigation is calculated in accordance with improved Elman neural network (ENN algorithms. Takagi-Sugeno-Kang (TSK fuzzy and improved ENN control are applied to adjust required power and steering, which allows the hull to move straight forward to a predetermined target position. The route will be free from outside influence and realize automatic navigation purpose.

  6. Turbulent boundary layer over a chine.

    Science.gov (United States)

    Panchapakesan, N. R.; Joubert, P. N.

    1999-11-01

    The flow over an edge aligned with the streamwise direction is studied as a representative of the turbulent boundary layers developing over hard chines found on the hulls of ships and catamarans. We present results of a traditional experimental investigation of this geometry in a wind tunnel with pitot tubes and hot-wires. The chine model consisted of two surfaces made of varnished fibre boards with leading edges of airfoil sections and a 90 degree corner. The boundary layer was tripped with wires close to the leading edge. The model was housed in a test section of length 6.5 m in a closed circuit wind tunnel. The experiments were conducted at a unit Reynolds number of 680,000 /m corresponding to a nominal free stream velocity of 10 m/s. The mean velocity field and the associated integral parameters obtained with pitot tube measurements are presented for different streamwise locations from 0.2 to 4.7 m from the trip wire. The flow at the two farthest locations were also studied with single and 'x' hot-wires. The secondary mean flow and the turbulence field in the corner region are described with these measurements.

  7. Archive of single-beam bathymetry data collected during USGS cruise 07CCT01 nearshore of Fort Massachusetts and within Camille Cut, West and East Ship Islands, Gulf Islands National Seashore, Mississippi, July 2007

    Science.gov (United States)

    DeWitt, Nancy T.; Flocks, James G.; Reynolds, B.J.; Hansen, Mark

    2012-01-01

    identifier to each cruise or field activity. For example, 07CCT01 tells us the data were collected in 2007 for the Coastal Change and Transport (CCT) study and the data were collected during the first (01) field activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity ID. Data were collected using a 26-foot (ft) Glacier Bay catamaran. The single-beam transducers were sled mounted on a rail attached between the catamaran hulls. Navigation was acquired using HYPACK, Inc., Hypack version 4.3a.7.1 and differentially corrected using land-based GPS stations. See the digital FACS equipment log for details about the acquisition equipment used. Raw datasets were stored digitally and processed systematically using NovAtel's Waypoint GrafNav version 7.6, SANDS version 3.7, and ESRI ArcGIS version 9.3.1. For more information on processing refer to the Equipment and Processing page.

  8. Archive of side scan sonar and swath bathymetry data collected during USGS cruise 10CCT01 offshore of Cat Island, Gulf Islands National Seashore, Mississippi, March 2010

    Science.gov (United States)

    DeWitt, Nancy T.; Flocks, James G.; Pfeiffer, William R.; Wiese, Dana S.

    2010-01-01

    activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity ID. Data were collected using a 26-foot (ft) Glacier Bay Catamaran. Side scan sonar and interferometric swath bathymetry data were collected simultaneously along the tracklines. The side scan sonar towfish was towed off the port side just slightly behind the vessel, close to the seafloor. The interferometric swath transducer was sled-mounted on a rail attached between the catamaran hulls. During the survey the sled is secured into position. Navigation was acquired with a CodaOctopus Octopus F190 Precision Attitude and Positioning System and differentially corrected with OmniSTAR. See the digital FACS equipment log for details about the acquisition equipment used. Both raw datasets were stored digitally and processed using CARIS HIPS and SIPS software at the USGS St. Petersburg Coastal and Marine Science Center. For more information on processing refer to the Equipment and Processing page. Post-processing of the swath dataset revealed a motion artifact that is attributed to movement of the pole that the swath transducers are attached to in relation to the boat. The survey took place in the winter months, in which strong winds and rough waves contributed to a reduction in data quality. The rough seas contributed to both the movement of the pole and the very high noise base seen in the raw amplitude data of the side scan sonar. Chirp data were also collected during this survey and are archived separately.

  9. 基于证据推理的大型海事巡逻救助船船型选择%Ship type selection of large-scale marine patrol and rescue ships based on evidence reasoning

    Institute of Scientific and Technical Information of China (English)

    高成男; 谢新连; 赵福波; 李猛; 包甜甜

    2014-01-01

    To choose the ship type of large-scale marine patrol and rescue ships scientifically,the evalua-tion index system of ship type selection is established from four aspects of cost,technology,energy con-sumption and appearance. The each index weight in the system is determined by Analytical Hierarchy Process (AHP),and the comprehensive evaluation on each ship type is carried out by the evidence rea-soning and IDS software. Taking the ship type selection of a marine patrol and rescue ship with 3 000 t for example,through evaluating such ship types as round-bilge ships,wave piercing catamarans and tri-marans,the feasibility of the method to ship type selection for large-scale marine patrol and rescue ships is verified.%为科学选择大型海事巡逻救助船船型,从成本、技术、能耗、外观等4个方面构建船型选择评价指标体系,运用层次分析法(Analytical Hierarchy Process,AHP)确定各指标权重,并采用证据推理法,借助IDS软件,对各船型进行综合评价。以3000吨级海事巡逻救助船船型选择为例,通过评价圆舭船型、穿浪双体船型和三体船型,验证该方法在大型海事巡逻救助船船型选择上的可行性。

  10. Inter-comparison of hydro-climatic regimes across northern catchments: Synchronicity, resistance and resilience

    Science.gov (United States)

    Carey, S.K.; Tetzlaff, D.; Seibert, J.; Soulsby, C.; Buttle, J.; Laudon, H.; McDonnell, J.; McGuire, K.; Caissie, D.; Shanley, J.; Kennedy, M.; Devito, K.; Pomeroy, J.W.

    2010-01-01

    The higher mid-latitudes of the Northern Hemisphere are particularly sensitive to climate change as small differences in temperature determine frozen ground status, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, seeks to improve our understanding of the sensitivity of northern catchments to climate change by examining their hydrological and biogeochemical responses. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). This briefing presents the initial stage of the North-Watch program, which focuses on how these catchments collect, store and release water and identify 'types' of hydro-climatic catchment response. At most sites, a 10-year data of daily precipitation, discharge and temperature were compiled and evaporation and storage were calculated. Inter-annual and seasonal patterns of hydrological processes were assessed via normalized fluxes and standard flow metrics. At the annual-scale, relations between temperature, precipitation and discharge were compared, highlighting the role of seasonality, wetness and snow/frozen ground. The seasonal pattern and synchronicity of fluxes at the monthly scale provided insight into system memory and the role of storage. We identified types of catchments that rapidly translate precipitation into runoff and others that more readily store water for delayed release. Synchronicity and variance of rainfall-runoff patterns were characterized by the coefficient of variation (cv) of monthly fluxes and correlation coefficients. Principal component analysis (PCA) revealed clustering among like catchments in terms of functioning, largely controlled by two components that (i) reflect temperature and precipitation gradients and the correlation of monthly precipitation and discharge and (ii

  11. METHODOLOGY OF THE HYBRID PROPULSION SYSTEM (DMP & DEP FOR TRIMARAN TYPE FAST PATROL BOAT

    Directory of Open Access Journals (Sweden)

    Aulia Widyandari

    2012-04-01

    Full Text Available There are lot of research done to develop a patrol boat, from the modification of hull model until propulsion system equipment. For example the model ship type AMV (Advanced Marine Vehicle was developed starting from the Catamaran, Trimaran and  Pentamaran model. Everything is aimed at obtaining the ship design that has the speed and stability. In addition to achieving high-speed vessel must be equipped with propulsion (Main Power is great, that means the main engine dimensions, auxiliary equipments and fuel tanks is too large. Many Limitations of space on the ship's engine room trimaran vessel is the main obstacle in designing propulsion system. Beside that Patrol boat should have many missions speed, so propulsion system should be designed at that conditions.   Hybrid propulsion is a combination of Diesel Mechanical Propulsion (DMP with Diesel Electric Propulsion (DEP. DMP system is connected directly to the propeller shaft (or through a reduction-gear. DMP has provide more efficiency rate of 95%. While DEP is only able to provide efficiency by 85% - 89% is slightly lower than DMP, but the DEP offers many advantages such as simplicity and suitability in the rotational speed settings, control systems, engine power production Redundancy, Flexibility in the design of equipments layout in engine rooms, noise, vibration and fuel consumption efficiency which affects the lower pollution.   Design of Hybrid Propulsion system can be satisfied and achieved the Power requirements and optimally at all speed condition of patrol boat. Therefore the author made using modeling Maxsurf-11.12 software and carried out various optimization of the choice of main engine, propeller and system conditions for fast patrol boat cruise. 

  12. The optimal access system for future far-offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Obdam, T.S.; Rademakers, L.W.M.M.; Savenije, L.B. [ECN Wind Energy, Petten (Netherlands)

    2013-12-15

    Operation and maintenance (O and M) of offshore wind turbines is one of the main cost drivers of offshore wind energy. One of the aspects critical for an efficient and cost-effective O and M strategy is the selection of the access system which is used to transfer technicians and, optionally, small spare parts. Currently, most offshore wind farms are located close to shore, and their size is relatively small. For these farms the typical access system consists of catamaran-like workboats, which are used to transfer both technicians and small spare parts. As wind farms move further offshore this O and M concept might no longer be cost-effective. Currently, different alternative O and M concepts are being considered for the future far-offshore sites. In this paper an extensive and holistic comparison of different O and M concepts including different access system solutions is presented. This analysis has been performed using the OMCECalculator, ECN's software for advanced O and M cost modelling. Different sites have been considered, which are typical for the future offshore wind farms that will be commissioned during the next five years. The results of the performed analyses indicate that when moving further offshore harbour-based O and M strategies are no longer economical, even when helicopters are added to the mix. Looking at farm-based O and M concepts a supply vessel with a compensated access gangway offers great potential. However, the calculations also indicate that its ability to transfer small spare parts, in addition to technicians, is crucial.

  13. 一种基于APDL语言的船舶波浪压力自动加载方法%An Approach to Automatically Loading Wave Pressure Using APDL in ANSYS

    Institute of Scientific and Technical Information of China (English)

    丁德勇; 郑杰; 谢伟; 胡要武; 杨龙

    2011-01-01

    针对全船结构强度直接计算中,波浪加载较为麻烦的问题,提出了一种ANSYS环境下的波浪压力自动加载的方法。该方法将三维水动力程序计算的船体表面的波浪压力经过插值算法转换到有限元结构单元上,压力数据文件读入ANSYS实现了自动加载。最后,利用该自动加载方法对一艘穿浪双体船进行加载。结果表明,该方法将波浪载荷计算和结构强度分析有机结合起来了,提高了波浪压力加载的准确性和效率。%Since wave pressure loading in the direct calculation of overall ship structural strength is a time-consuming job, an automatic loading approach in the ANSYS environment was proposed. Using this method, wave pressure on ship surface calculated by 3D hydrodynamic program was transferred to Finite Element model by interpolation algorithm. The pressure data file was read into ANSYS to fulfill the automatic loading process. The automatic approach was applied to a wave piercing catamaran as an example. The results show that the proposed approach can combine the wave load calculation with ship structural strength analysis, greatly improving accuracy and efficiency of wave pressure loading.

  14. Multi-tiered sensing and data processing for monitoring ship structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles [Los Alamos National Laboratory; Salvino, Liming [NSWCCD; Lynch, Jerome [UNIV. OF MICHIGAN; Brady, Thomas [NSWCCD

    2009-01-01

    A comprehensive structural health monitoring (SHM) system is a critical mechanism to ensure hull integrity and evaluate structural performance over the life of a ship, especially for lightweight high-speed ships. One of the most important functions of a SHM system is to provide real-time performance guidance and reduce the risk of structural damage during operations at sea. This is done by continuous feedback from onboard sensors providing measurements of seaway loads and structural responses. Applications of SHM should also include diagnostic capabilities such as identifying the presence of damage, assessing the location and extent of damage when it does occur in order to plan for future inspection and maintenance. The development of such SHM systems is extremely challenging because of the physical size of these structures, the widely varying and often extreme operational and environmental conditions associated with the missions of high performance ships, the lack of data from known damage conditions, the limited sensing that was not designed specifically for SHM, the management of the vast amounts of data, and the need for continued, real-time data processing. This paper will discuss some of these challenges and several outstanding issues that need to be addressed in the context of applying various SHM approaches to sea trials data measured on an aluminum high-speed catamaran, the HSV-2 Swift. A multi-tiered approach for sensing and data processing will be discussed as potential SHM architecture for future shipboard application. This approach will involve application of low cost and dense sensor arrays such as wireless communications in selected areas of the ship hull in addition to conventional sensors measuring global structural response of the ship. A recent wireless hull monitoring demo on FSF-I SeaFighter will be discussed as an example to show how this proposed architecture is a viable approach for long-term and real-time hull monitoring.

  15. Enhanced mixing downstream of a pile in an estuarine flow

    Science.gov (United States)

    Lass, H. U.; Mohrholz, V.; Knoll, M.; Prandke, H.

    2008-11-01

    We studied the impact on stratification and mixing of a bridge pile in a stratified shear flow at the Western Bridge of the Great Belt Fixed Link, Denmark, in January and April 2006. Stratification was measured with high horizontal resolution by towed CTD chains and dissipation of turbulent kinetic energy was measured by a free-falling MSS 90 microstructure profiler equipped with shear probes. Background stratification and current were measured by standard CTD and a bottom-mounted ADCP, respectively. The spatial and temporal variability of the flow field close behind a single pile was measured by an ADCP mounted on a small catamaran tethered to this pile. A shear background flow of varying strength was observed with an inflow of up to 80 cm s - 1 in the surface layer and an outflow of 10 cm s - 1 in the bottom layer. The brackish surface layer was separated from the saline Kattegat water in the bottom layer by an intermediate layer resulting in a Brunt-Väisälä frequency of up to 100 cycles per hour (cph). The maximum Reynolds number ( Re) and internal Froude number ( Fr) were 4.6 × 10 6 and 1.3, respectively. Eddies occurred downstream of a pile with a characteristic diameter of the pile and a frequency corresponding to a von Kármán vortex street when near-surface Fr > 0.7. Enhanced mixing was observed in the von Kármán vortex streets, which caused an increase in salinity by a few psu in the surface mixed layer of the eddy up to 400 m downstream of the piles. Differential advection by cross-channel circulation smeared out laterally from the wakes' salinity anomalies and turbulence. The dissipation of turbulent kinetic energy in the intermediate layer increased by an order of magnitude downstream of the piles as a function of Fr when Fr > 0.7. This enhanced mixing reduced the mean potential energy anomaly downstream by some 10 Jm - 3 in the upper 15 m depth and caused an upstream-directed baroclinic pressure gradient of the same order as the barotropic

  16. A Numerical Method for Predicting Wash Waves of SES%一种计算SES船尾波(Wash wave)的数值方法

    Institute of Scientific and Technical Information of China (English)

    谢楠; Andrzej JASIONOWSKI; Dracos VASSALOS

    2004-01-01

    A numerical method is presented for predicting wash waves of Surface Effect Ships (SES)at deep waters.The wash waves of the SES are represented by the wave-making of a moving rectangular pressure distribution over the air cushion. Basing on the linear potential theory, the wash waves can be analytically expressed as integrals whose integrands oscillate with high frequency.The numerical procedure involves transformation of the integral variables,such that the integrands are monotonic for different vessel speed,shape of the pressure patch and locations of the wave to be calculated,and easy to facilitate the numerical calculation.The singularities of the integral can be also removed. Numerical results show that the present method is of high computational efficiency and with good agreement with the published results. Some results of wash waves of SES are presented and discussed.The characters of local and non-local effect parts of the wash wave of SES are discussed. Attempt is also tried to apply the present method in predicting wash wave of conversional catamaran,the comparison between the prediction and the model test measurement shows fairly good agreement.%本文提出了一种无限深水中表面效应船(Surface Effect Ship,SES)尾波(Wash wave)数值方法.SES的尾波被表达成分布在气垫上的压力在静水中航行产生的兴波波浪场.在线性势流假设下,该尾波可解析地表示为积分形式,而其被积函数带有奇性并高频振荡.文中提出了一个变换,使变换后对不同的航速,SES船形(气垫形状)和所要计算的波浪场位置尾波计算中的被积函数是单调变化,因而易于数值计算.积分中的奇性也予以去除.数值计算结果表明本文提出的数值方法具有较高的计算效率而且结果与已发表的结果吻合良好.文中给出了一些SES船尾波(Wash wave)的计算结果,并进一步分析了SES尾波(Wash wave)中的局部和非局部波浪场成分.文中还尝试使用本

  17. Experiences on Altimeter Calibration at Ibiza Island and Cape of Begur (Spain)

    Science.gov (United States)

    Martinez Benjamin, J. J.; Martinez Harcia, M.; Ortiz Castello, M. A.; Talaya, J.; Baron, A.; Rodriguez Velasco, G.; Martín Davila, J.; Garate, J.; Bonnefond, P.; Garcia, C.

    2006-07-01

    Three preliminary camp aigns for TOPEX /POSEIDON (T/P) wer e made in March 1999 and July 2000 and for JASON-1 in August 2002, in the NW Mediterran ean Sea at th e Begur Cape area. Dir ect abso lute altimeter calibration , and mapping of the sea surface, w ere made in these camp aigns from dir ect overflights using GPS buoys with a toroidal design performed at the I CC based in the orig inal design of the Univ ersity of Colorado at Boulder and a estimation of the TOPEX A lt- B bias w as made. A Spanish JASON-1 geoid gradien t campaign with Fench support has been made in June 2003 at the Ibiza island in the NW Mediterr anean Sea. Th e main objectiv e has b een to map w ith a new d esign ed, builded and calibrated GPS catamar an, the lo cal geoid gradien t in three ar eas around Ibiza island under the ascending (187) and descending (248) Jason-1ground tracks. The catamaran equ ipped with two GPS antennas to perform continuous sea lev el measur ements was towed by the Patro l Dev a from th e Span ish N avy. Five GPS reference stations were dep loyed on Ibiza island: one in Portinatx, two in San Anton io and two in Ibiza. The marin e geo id has been used to relate the coastal tide gauge data from Ibiza and San An tonio h arbours to off- shore altimetric data. In th e framework of the campaign, the levelling of the Ibiza and San Anton io tide gauges to the r espective GPS mark ers w as p erformed. We present synth esis of the resu lts obtained from Topex/Poseidon and th e first r esults on Jason-1 altimeter calibration using the direct measurements from GPS buoys and the derived marin e geoid. Th e Ibiza results agree relativ ely w ell with resu lts ob tained at Corsica, Harvest and Bass Strait calibration permanen t sites. Moreov er, the geod etic activities (e.g., GPS, levelling) has p ermitted to build a very accurate (few mm) local n etwork link ed to th e European one, w ith a reference frame compatible with th e satellite altimetry missions (ITRF2000). The GPS

  18. Immersive, hands-on, team-based geophysical education at the University of Texas Marine Geology and Geophysics Field Course

    Science.gov (United States)

    Saustrup, S.; Gulick, S. P.; Goff, J. A.; Davis, M. B.; Duncan, D.; Reece, R.

    2013-12-01

    The University of Texas Institute for Geophysics (UTIG), part of the Jackson School of Geosciences, annually offers a unique and intensive three-week marine geology and geophysics field course during the spring/summer semester intersession. Now entering its seventh year, the course transitions students from a classroom environment through real-world, hands-on field acquisition, on to team-oriented data interpretation, culminating in a professional presentation before academic and industry employer representatives. The course is available to graduate students and select upper-division undergraduates, preparing them for direct entry into the geoscience workforce or for further academic study. Geophysical techniques used include high-resolution multichannel seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, sediment coring, grab sampling, data processing, and laboratory analysis of sediments. Industry-standard equipment, methods, software packages, and visualization techniques are used throughout the course, putting students ahead of many of their peers in this respect. The course begins with a 3-day classroom introduction to the field area geology, geophysical methods, and computing resources used. The class then travels to the Gulf Coast for a week of hands-on field and lab work aboard two research vessels: UTIG's 22-foot, aluminum hulled Lake Itasca; and NOAA's 82-foot high-speed catamaran R/V Manta. The smaller vessel handles primarily shallow, inshore targets using multibeam bathymetry, sidescan sonar, and grab sampling. The larger vessel is used both inshore and offshore for multichannel seismic, CHIRP profiling, multibeam bathymetry, gravity coring, and vibracoring. Field areas to date have included Galveston and Port Aransas, Texas, and Grand Isle, Louisiana, with further work in Grand Isle scheduled for 2014. In the field, students work in teams of three, participating in survey design, instrument set-up, field deployment

  19. 港珠澳大桥非通航孔85 m连续组合梁桥施工关键技术%Key Construction Techniques for 85 m Non-navigational Channel Con-tinuous Composite Girder Bridge of Hongkong-Zhuhai-Macao Bridge

    Institute of Scientific and Technical Information of China (English)

    潘军

    2016-01-01

    港珠澳大桥浅水区非通航孔桥为11联双幅85 m连续组合梁桥,基础采用钢管复合桩,承台及墩身采用预制拼装结构,承台深埋于海床内,上部结构采用组合梁结构。桥位处地质复杂、环境恶劣,利用“小天鹅”号运架双体船搭载整体导向架系统,实现复合桩基础钢管三次定位,精确控制钢管插打;承台+底节墩身整体预制时钢筋按4个模块分别绑扎,组拼成整体后应用自动化开合模板浇筑混凝土,并采用裂纹控制技术及防腐措施;承台+底节墩身预制构件采用“小天鹅”号运架一体船运输、起吊下放进入锁口钢套箱围堰内,通过复合桩桩顶三向调节装置精确定位安装;组合梁的钢梁在工厂加工成板单元后,船运至中山预制场进行整孔组拼,混凝土桥面板采取纵向分块、横向整幅预制,二者结合成组合梁后由“天一号”运架一体船逐片吊装。%The non‐navigational channel bridge in the shallow water area of Hongkong‐Zhuhai‐Macao Bridge is a continuous composite girder bridge with separated left and right decks .The bridge has 11 continuous units of spans of 85 m .T he foundation of the piers is formed of concrete‐filled steel tubular piles ,the pile caps and pile shafts were prefabricated and assembled in the workshop ,and the pile caps were deeply buried in the seabed .The superstructure adopts compos‐ite girder structure .Complicated geological condition and harsh environment render the bridge site quite challenging for construction .The Crane Little Swan ,a catamaran used to lift and erect gird‐ers ,was employed to carry the overall guiding frame system ,to realize three times of positioning of the composite foundation steel tubes and precisely control the driving of the steel tubes .The pile cap and the bottom lift of the pier are monolithically prefabricated ,during the manufacture of which ,the reinforcement was divided

  20. Introduction

    Science.gov (United States)

    Narlikar, J. V.; Sathyaprakash, B. S.

    2014-03-01

    colleague Kumar (S.M.) Chitre and the younger one, Ajit Kembhavi, and the organizational infrastructure of TIFR. In particular, the then administrator dealing with scientific meetings, Parelkar enthusiastically joined me to set up the local boundary conditions in Goa. To get our priorities right, we first picked upon Hotel Mandovi in Panjim (Capital of Goa) as the nodal hotel for catering, accommodation, and arrangements of the academic sessions. We were expecting around 100 participants with 50% from abroad. Kamat, the Manager of Hotel Mandovi, promised all help including beds in nearby hotels to make up any shortfall. Regarding the quality of food, for which Hotel Mandovi was justly famous, its in-charge, Satish Prabhu took care of all our worries. Delegates may still recall the various Goan delicacies featured on the conference menus. Parelkar negotiated the basic deal with the hotels to extract the maximum benefits for the conference. But we were still rather vulnerable in lack of the local conditions. An unexpected helping hand came to make up for our lack of local knowledge. The amateur astronomer organization, called ''Friends of Astronomy in Goa'', led by their venerable President, Percival Noronha offered to run errands for us and play the role of local volunteer. Noronha had been associated with the state government of Goa, since the days when it was a Portuguese colony. His 'inside knowledge' came in useful, especially when he advised us to request the Chief Minister, Pratapsingh Rane to entertain the conference participants in the state catamaran. Somewhat hesitatingly, I wrote a request letter, and to my delightful surprise, the CM agreed. Indeed, the boat-ride followed by the CM's riverside banquet was the entertainment high point of the conference. The food, Goan drinks, and musical entertainment were well appreciated by the participants, and an uninitiated person might be forgiven for thinking that ICGC stood for ''International Conference on Goan