基于涡格法的螺旋桨剖面拱线设计

船舶螺旋桨的叶剖面形状与其负荷形式、效率、空泡等水动力性能密切相关。剖面拱线与剖面的负荷分布有直接关系。为了设计给定负荷分布的剖面拱线,提出用升力分布定义螺旋桨剖面拱线的负荷分布,在此基础上对升力分布进行参数化表达,并进行拱线设计。拱线的设计采用Newton-Raphson迭代方法使拱线的升力分布满足给定值,拱线的性能计算采用基于薄翼理论的二维涡格法。计算表明:涡格法与Newton-Raphson迭代方法相结合能够精确并快速设计满足给定升力分布的拱线。最后,修改升力分布的部分参数,并由此设计了SJ系列拱线供剖面设计参考。     

膜盘强度计算方法

系统分析膜盘的基本工况和受力模型,并利用Ansys计算软件,形成基于有限元计算方法的膜盘强度计算方法。同时以目前常用的直线、锥形及双曲线3种型线膜盘为例,分析膜盘型线内、外半径比值,型线最薄点厚度等参数对膜盘危险区域的影响。论述膜盘型线设计的重要性,并给出膜盘型线设计时主要设计参数的取值范围,为膜盘型线危险区域的设计提供参考。     

光顺数学模型与振动数理论在船体型线优化设计中的应用

船体型线设计是船舶设计领域中的难点,船体型线设计是否合理直接关系到船舶航行阻力、航速以及航行的稳定性。在传统的船体型线设计中,设计时间较长,设计过程过于复杂化,降低了设计效率。而采用光顺数学模型和振动数理论可显著提升设计效率和设计质量。本文从阐述光顺数学模型和振动数理论入手,分析了船体型线优化设计流程,并提出光顺数学模型与振动数理论在船体型线优化设计中的具体应用。     

深水多成分悬链线锚泊系统优化设计及应用研究

深水多成分悬链线锚泊系统的设计要考虑多种成分的组合优化问题.本文根据深水多成分锚泊线悬链线方程,结合设计中需要考虑各种材料的特征,提出多目标函数的多成分锚泊线优化模型,通过遗传算法求解确定模型的最佳形式,并结合图谱设计方法研究将模型引入锚泊系统设计实例.     

基于NAPA的圆舭艇型线参数化设计方法

型线设计是船舶总体设计的重要内容之一.通过圆舭艇船体几何形状分析,建立了几何特征线和点的参数表达式,并利用NAPABASIC语言开发了型线参数化设计宏程序,从而为圆舭艇船型数字化设计探索了一条高效的新途径.     

基于CAD二次开发的Ⅴ型无压载水船

基于现有的Ⅴ型无压载水船型线设计理论,提出一种改进的型线设计变换方法,即基于母型船的横剖面面积不变,保证船长、设计吃水和排水量基本不变,增大船宽,生成船底倾角,并考虑在倾斜的船底上生成平板龙骨。利用AutoCAD软件的二次开发实现设计船型线的快速生成,并在此基础上快速提取三维型值点导入CATIA软件中生成点和型线,最后利用CATIA进程内VBA脚本编程方法实现快速建模。结果表明,改进的型线变换设计方法可靠,通过二次开发软件可生成光顺的型线和实体模型,为后续的性能分析提供基础。     

豪华邮轮球首设计

考虑台湾海峡和东南亚航区风浪情况,在船舶最新设计理念及有关理论指导下,结合以往在型线设计方面的经验和基础船型数据库,研究设计三种新颖的豪华邮轮船型,并采用CFD 软件fluent和Resistance计算并优化分析船体型线及阻力,获得该适合航区较佳的船型。     

基于3D打印技术的无压载水船体型线设计系统

本文介绍了公理化设计方法,并基于公理化设计方法提出适合船舶3D打印的设计方法。分析了船舶3D打印需要的设计约束以及3D打印的实现目标,基于NURBS曲线提出了船体的数学型线设计方法。总结了无压载水船体结构,设计了基于3D打印技术的无压载水船体型线设计系统。     

浅谈用NAPA建立并光顺型线

简要介绍TN用NAPA设计型线及在光顺方面的应用体会。并结合实际工作需要,编写了叮将NAPA型线转换剑TRIBONM3中去的语言程序,方便了与生产设计精光顺的对接。     

深水多成分悬链线锚泊系统优化设计及应用研究

深水多成分悬链线锚泊系统的设计要考虑多种成分的组合优化问题。本文根据深水多成分锚泊线悬链线方程，结合设计中需要考虑各种材料的特征，提出多目标函数的多成分锚泊线优化模型，通过遗传算法求解确定模型的最佳形式，并结合图谱设计方法研究将模型引入锚泊系统设计实例。     

钢-混凝土箱型组合斜拉桥主梁混凝土收缩徐变分析

组合梁斜拉桥兼有混凝土和钢结构的优点,但作为两种材料的结合体,混凝土收缩徐变会引起组合截面的应力重分配,可能促使混凝土裂缝的提前出现或加速裂缝的扩展,从而降低结构的受力性能和耐久性。采用有限元方法分析了混凝土收缩徐变对组合梁斜拉桥主梁应力重分布的影响,并对混凝土的加载龄期的影响进行了参数分析。计算结果表明：混凝土加载龄期越早,组合截面的应力重分布越明显;混凝土收缩徐变对混凝土桥面板的应力影响不大,但对钢梁应力影响较为显著,钢梁的应力增量达到钢材容许应力的30%左右。     

BIM技术在航道建设中的作用

航道工程具有施工工期长、施工影响因素多等特点。在航道工程的设计、施工、维护的各个阶段,随着对精细化管理的需求日趋提高,传统的实施方法已不能满足工程的强度与精度要求。从航道工程和BIM的特性入手,探讨了BIM技术在航道工程设计、施工、维护等各阶段的应用。在保证设计合理性的前提下,可通过BIM模型完成设计意图的表达与传递,从而保证航道工程的施工质量,以及后续维护阶段航道整治建筑物安全、稳定地发挥其作用。     

便携式船舶液舱容积查询系统的设计

介绍了便携式船舶液舱容积查询系统的软硬件设计思路。该系统通过现场获得液面高度,输入纵倾值、视密度、视温度等参数后,由人机界面自动显示液舱内油品的质量和容量,并可对输入参数以及计算结果进行存储记录,减少了现场计量人员查表计算的工作量,提高了工作效率,保证了计量结果计算的准确可靠性,便于数字化管理和事后检验。     

Evolving the subspace of the three-dimensional multiscale ocean variability: Massachusetts Bay

A data and dynamics driven approach to estimate, decompose, organize and analyze the evolving three-dimensional variability of ocean fields is outlined. Variability refers here to the statistics of the differences between ocean states and a reference state. In general, these statistics evolve in time and space. For a first endeavor, the variability subspace defined by the dominant eigendecomposition of a normalized form of the variability covariance is evolved. A multiscale methodology for its initialization and forecast is outlined. It combines data and primitive equation dynamics within a Monte-Carlo approach.The methodology is applied to part of a multidisciplinary experiment that occurred in Massachusetts Bay in late summer and early fall of 1998. For a 4-day time period, the three-dimensional and multivariate properties of the variability standard deviations and dominant eigenvectors are studied. Two variability patterns are discussed in detail. One relates to a displacement of the Gulf of Maine coastal current offshore from Cape Ann, with the creation of adjacent mesoscale recirculation cells. The other relates to a Bay-wide coastal upwelling mode from Barnstable Harbor to Gloucester in response to strong southerly winds. Snapshots and tendencies of physical fields and trajectories of simulated Lagrangian drifters are employed to diagnose and illustrate the use of the dominant variability covariance. The variability subspace is shown to guide the dynamical analysis of the physical fields. For the stratified conditions, it is found that strong wind events can alter the structures of the buoyancy flow and that circulation features are more variable than previously described, on multiple scales. In several locations, the factors estimated to be important include some or all of the atmospheric and surface pressure forcings, and associated Ekman transports and downwelling/upwelling processes, the Coriolis force, the pressure force, inertia and mixing.     

船用五螺杆泵低噪声工艺技术

本文通过对现有的某船用五螺杆泵的频谱特征和振动特性进行分析,找出主要振动噪声源,通过改进进口流道面积,并对现有的螺杆加工工艺进行研究和优化改进,改进后的设计通过样机的制造,并经过试验对比分析,进一步验证方法的可行性和预期减振效果。     

High-resolution surveys of the biogeochemistry of the New England shelfbreak front during Summer, 2002

We present the observations from a pair of field experiments at the New England shelfbreak front in June and August of 2002, each consisting of 14 cross-frontal surveys using the Lamont Pumping SeaSoar. Measurements of the front's physical, chemical, and bio-optical characteristics were made at high spatial and temporal resolution. The front, based on water-column hydrographic distributions, was found within a few km of the 200 m isobath during both cruises. We present here composite sections, based on averages of individual sections shifted in space to a common frontal location, of the cross-frontal distributions of these properties as a measure of the mean state of the front in both June and August. The observations show the familiar temperature, salinity, and density distributions of the summertime front, dominated by surface thermal heating. Nutrient and bio-optical distributions show the combined effects of water-mass exchange and biological processes. T, S, silicate, and phosphate distributions are suggestive of cross-frontal exchange of slope- and shelf waters, although transport mechanisms and pathways are not apparent. These properties, along with nitrate and optical measures of the suspended particle distributions, show vertical displacements of isopleths as the front is approached: property contours slope upwards toward the front from the shoreward side, and downwards toward the front from the seaward side. Again, actual water-movement pathways are not constrained by these suggestive patterns. Bio-optical distributions show elevated indicators of photosynthetic efficiency both seaward and shoreward of the front, but the front itself is a minimum in biomass. Accumulation of photosynthetic biomass appears to be controlled primarily by nitrate scarcity in waters within and above the pycnocline. At the base of the pycnocline, light limitation appears to be the controlling factor, although the base of the euphotic zone is deeper than the biomass maxima and the base of the pycnocline. Mechanisms explaining this phenomenon are unclear, but tenuous evidence suggests low stratification at the depth of the 1% light level may not allow phytoplankton to optimize for the low-light, high-nutrient conditions at depth. Cross-frontal differences in nutrient and bio-optical parameters, particularly in August, suggest distinct phytoplankton assemblages, and the presence of calcite-forming or nitrogen fixing groups to the community structure, especially in very shallow waters across the front and in pycnocline waters seaward of the front.     

二次预应力外包钢组合梁叠合楼盖动力特性有限元分析

二次预应力外包钢组合梁叠合楼盖结构体系是目前在外包钢组合梁和预应力结构理论研究基础上提出的新型楼盖体系。这种新型式的组合式叠合结构利用轻骨料混凝土大幅地减轻结构自重,增加楼盖体系保温隔热和隔音性能,同时通过两次预应力的张拉,使该新型楼盖系统适合了大跨度工程施工及承载,以及充分发挥各组合材料物理力学特性的要求,为该类型结构推广应用奠定了基础。论文采用有限元软件ANSYS建立叠合楼盖三维实体模型。对叠合楼盖的动力特性进行了分析,并通过改变预应力的大小、预应力筋的布筋形态和柱的约束条件等进行参数讨论。文中分析了各参数对结构体系自振频率及振幅产生的影响并得到了一些规律性的结论,对进一步研究该体系的动力性能有一定的指导意义。     

A review of physical flexible ship models used for hydroelastic experiments

Hydroelasticity of ships has been established as a necessary form of investigation for both slender ships and high-speed craft. Experimental investigations have spanned various topics, including symmetric and antisymmetric, harmonic and transient, linear and nonlinear responses. Models have varied in size and the way the structure is modelled, depending of the focus of the investigation. The multitude of interacting physical mechanisms introduce almost-impossible-to-resolve scaling issues, and the eventual compromises depend on the aim of the investigator. This publication provides a comprehensive review of the evolution of these experimental techniques, from the first appearances of the field to the modern state-of-the-art and potential future directions.     

重大工程中的断裂构造探测

工程建设中的断裂构造对场地稳定和建筑物安全的影响已经引起了重视,针对断裂构造成因复杂、大小不一、埋藏深度不一、内含物的成分及性状差异极大,造成对断裂构造探测的针对性、直观性不足的问题,进行探测技术路线和探测方法的研究和论述,采用基于区域地质条件分析,运用多种手段对表部和隐伏的断裂构造进行深入的探测方法,探测成果直观、可靠,对工程建设宏观的安全性评价、研究场地内断裂构造对工程的影响提供详尽的资料。结合上海洋山深水港区LNG码头和后方堆场工程,验证该探测技术路线和方法能有针对性地、直观地探测工程场地内的断裂构造。     

高桩码头-岸坡相互作用有限元数值模拟

高桩码头-岸坡体系的相互作用机理一直是困扰工程界的难题。基于某突堤的现场勘察资料和土体参数,建立了高桩码头与岸坡相互作用的二维平面应变问题和三维空间问题的弹塑性有限元模型,采用与M ohr-Co lum n准则匹配的D rucker-P rager准则作为土的屈服准则,分析了桩基-岸坡体系的变形机理,同时,针对二维和三维情况各种工况组合进行了对比分析,并结合土体参数和现场测斜资料,分析了高桩码头-岸坡体系的变形规律,并指出了影响桩、梁和岸坡体系变形的主要因素,并建议了合理的治理方案。