【作者】 杨铭；

【导师】 毛筱菲；

【作者基本信息】 武汉理工大学 ， 船舶与海洋结构物设计制造， 2010， 硕士

【摘要】 目前,优化作为提高性能的重要手段,在设计过程中越来越多的被设计者所采用。而为了改变船舶性能,较为直观的方法就是控制影响性能的船型要素,如我们所熟悉的影响船舶阻力的主要参数有：船长(L),宽(B),吃水(T),棱形系数(Cp),纵向浮心位置(1cb),船舯系数(Cm)等。作为一种特殊船舶,金枪鱼围网渔船的设计者为寻求较好耐波性性能的船型,在设计初期必须对影响渔船耐波性的船型要素有所了解,以便在设计过程中选取合适的船型参数及在性能优化过程中对已有参数进行必要的改进以得到具有更好耐波性能的渔船船型。然而,对单一船型进行计算,仅仅可以作为对此船型性能的评估检验,不具有类比性,而且试验耗费的人力、物力、财力是巨大的。为了得到船型要素对耐波性的影响,必须对系列船型进行系统计算,得出不同参数下船型的运动和载荷,相互对比,给设计者提供有效的参考依据。鉴于此,作者利用iSIHGT这个多学科优化软件平台,初步搭构了一个基于此优化平台软件的船型生成和耐波性优化优化系统。通过改变其中的若干个船型参数,而保持其他船型参数基本不变,进行船型变换,随后将经变换所得船型进行进行耐波性计算,进行优化,得到理想的符合要求的船型。优化系统主要包含两大模块：第一个模块是船型变换程序,通过对参数的控制,来生成一系列船型；第二个模块是基于Wasim的耐波性计算结果所绘制图谱的耐波性插值计算程序,以有义纵摇角、砰击程度、首部垂向加速度、有义横摇角等船舶运动响应指标为目标。本文中,作者以金枪鱼围网渔船这一热门船型作为算例,验证了这套基于iSIGHT的船型生成和耐波性优化系统。首先,作者分析船舶主尺度和船型要素对耐波性的影响,确定了影响耐波性的主要参数,接着,通过对这些参数的控制由母型船派生出不同方形系数和不同船宽比的系列船型,再对船型库内所有船型的耐波性进行了详细计算,并绘制了图谱,建立起了船舶主尺度与主要船型要素与金枪鱼围网渔船在波浪中运动响应的关系。再根据绘制出的图谱,编写了插值程序,并连同船型变换程序建立了一套完整的以寻找有义纵摇角、首部垂向加速度和砰击情况以及有义横摇角最理想船型为目标的优化系统,寻找出金枪鱼围网渔船在波浪中运动稳定性最优的船型。更多还原

【Abstract】 At present, optimization, as an important measure to improve performance of ships, is more and more adopted in engineering by designers. In order to change the performance of ships, an obvious measure is to control the factors that might influence performance. For instance, the factors that affect ship resistance mainly include length (L), width (B), draft (T), prismatic coefficient (Cp), longitudinal center of buoyancy (lcb), midship coefficient (Cm), and so on. As a special ship, the designer of tuna seiner ship must learn about the factors that might affect ship seakindliness in the beginning of engineering, so as to select proper parameters during engineering and make necessary improvement to existing parameters during performance optimization for fishing ships with better seakindliness.However, calculation to single type of ship can only serve as performance evaluation and examination. There is no comparability, and meanwhile tests consume considerable labor, equipment and expense. In order to figure out the influence of ship parameters to seakindliness, systematic calculation on series of ship types is necessary, so as to identify ship movements and loads in different parameters, and compare one another to provide effective reference for designers. In view of the above stated, the author established a ship optimization system, using ISIHGT, a multi-discipline optimization software platform. The system optimizes ship to satisfy certain requirements by changing certain parameters and keeping other parameters almost unchanged, and then set certain parameters as targets. This system is mainly consistent of tow modules. The first is a ship form change program, which generates series of ship forms by controlling parameters. The second is an interpolation system of seakindliness calculation results, based on WASIM. The interpolation system takes ship vertical movement indexes as target, such as pitch angle, calculate the series of ship forms generated, and search for the best one.In this thesis, the author established a ship form change program based on iSIGHT platform, and by controlling series of parameters, series of ship forms with different fineness coefficient and different breadth-draft ratio are generated from original ship form. Then, detailed calculation to vertical movement of tuna seiner ship was conducted, and figures were drawn. By analysis, the influence of main ship dimension and ship factors to vertical movement of tuna seiner ship in waves was concluded. And further, according to the figures drawn, an interpolation program was developed. Together with the ship form change program, the two programs form a complete set of optimization system to search for ship forms that have most favorable pitch angle, head vertical acceleration, strike situation and roll angle, and the tuna seiner ship form with the best stability in movement in waves was found out.更多还原