海洋监测拖曳系统中拖缆导流套设计

拖缆导流套是提高海洋监测拖曳系统效能的有效手段之一.阐述了导流套的功能,分析了导流套的受力,以及拖缆导流套设计中要考虑的若干问题,并介绍了自行设计的导流套性能.     

An optimization approach for fairing of ship hull forms

This paper presents a numerical fairing procedure to be used at the preliminary design stage to create high-quality ship hull form geometry. The procedure is based on a variational optimization approach in which a fairness measure related to the surface curvature is the objective function to be minimized subject to a set of geometric constraints to ensure that the final form has the required geometric characteristics. The optimization variables are selected as the control points of a B-spline surface representing the initial hull form. A nonlinear direct search technique is employed to solve the problem. The methodology is applied for typical ship forms to indicate that, provided that the designer can specify appropriate design objectives and geometric constraints, the methodology can produce alternative hull forms with significantly improved fairing characteristics. The choice of the fairness objective function is shown to have a crucial effect on the quality of the hull surface. Highly nonlinear exact fairness functionals yield surfaces of high quality at the expense of high-computerized effort.     

深水滑翔机器人耐压壳体结构优化设计

针对深水滑翔机器人耐压壳体在深水中压缩变形和海水密度随水深增大而变化等因素造成驱动浮力变化问题,利用压缩变形和密度变化对驱动浮力影响的互补特性,归纳了载体耐压壳体结构优化设计方法.保证耐压壳体抗压条件和质量最小前提下采用结构优化设计方法,降低耐压壳体压缩变形和海水密度变化对驱动浮力的影响,提高系统能源的利用率.     

An automated computational method for planing hull form definition in concept design

This paper describes the development of a computer-based method for producing chined planing boat hull forms adequate to be applied in concept design. The method is based on a principle where the designer specifies a small set of critical parameters he/she wishes obtain or keep preserved and generates a complete hull form, without the traditional skilled recourse of giving stations point by point. From this set of parameters a detailed and faired drawing with offsets is generated very quickly. The method allows, in its execution mode, the flexibility to modify, adjust and enlarge the input set of parameters. The method was created to allow both (1) automated hull form definitions when integrated to an existing computer system and (2) quick but detailed preliminary calculations of stability, lift and drag, volumes and internal space allocations, sea-keeping estimates, etc., all with very reasonable precision. As application examples some planing boat hull forms are generated. Some are typical and others less usual. The later ones are defined to show the method's limits, in order to validate it.     

基于iSIGHT重于水的无人自治潜水器概念设计及优化方法

介绍一种新型重于水的无人自治潜水器的概念设计及主艇体优化方法,阐述了主艇体、机翼、尾翼等设计原理。以飞鱼Ⅱ设计过程为例,详细描述了重于水的无人自治潜水器概念设计流程,并通过iSIGHT优化设计软件对主艇体的设计参数进行优化。优化结果表明,优化后主艇体重量能够减小48%,阻力减小2.9%。     

An inverse hull design approach in minimizing the ship wave

The Levenberg–Marquardt Method (LMM) and a panel code for solving the wave-making problem are utilized in an inverse hull design problem for minimizing the wave of ships. A typical catamaran is selected as the example ship for the present study. The hull form of the catamaran is described by the B-spline surface method so that the shape of the hull can be completely specified using only a small number of parameters (i.e. control points). The technique of parameter estimation for the inverse design problem is thus chosen. The LMM of parameter estimation, which is the combination of steepest descent and Newton’s methods, has been proven to be a powerful tool for the inverse shape design problem. For this reason it is adopted in the present study.In the present studies, the inverse hull design method can not only be applied to estimate the hull form based on the known wave data of the target ship but can also be applied to estimate the unknown hull form based on the reduced wave height. The optimal hull forms of minimizing wave for a typical catamaran in deep water at service speed and at the critical speed of shallow water are estimated, respectively. Moreover, a new hull form with the combining feature of the optimal hull forms for deep water and shallow water is performing well under both conditions. The numerical simulation indicates that the hull form designed by inverse hull design method can reduce the ship wave significantly in comparison with the original hull form.     

适用于浅海油田的高速交通艇设计

研究设计了一艘适用于浅海油田的高速交通艇，该艇采用深V线型和在侧斜螺旋浆，设有主动式减摇鳍。实船航行表明该艇具有优良的耐波性。     

Optimum design of multiple intersecting spheres deep-submerged pressure hull

The multiple intersecting spheres (MIS) pressure hull is a logical derivative of the single unstiffened sphere, which is frequently used for deep operating, small submersibles because of its attractive low buoyancy factor. This paper investigates the optimum design of an MIS deep-submerged pressure hull subjected to hydrostatic pressure, using a powerful optimization procedure combined the extended interior penalty function method (EIPF) with the Davidon–Fletcher–Powell (DFP) method. In this study, the thickness of the shell, the width of the rib-ring, the inner radius of the rib-ring and the angle of intersection of the spherical shell are selected as design variables, and structural failure and human requirements are considered to minimize the buoyancy factor. Additionally, a sensitivity analysis is performed to study the influence of the design variables on the optimal structural strength design. The results reveal that the shell thickness is most important to lobar buckling strength, and that rib-ring width, rib-ring inner radius and spherical shell intersection angle are most important to rib-ring hoop strength. Optimization results may provide a valuable reference for designers.     

An inverse design approach for minimising wake at propeller plane using CFD

Knowledge of wake characteristics in the stern region is important for ensuring good propeller design and performance. This work examines the utility of CFD in the analysis of flow in the case of full aft beam vessels having characteristic cut stern shape to facilitate propeller aperture. The underwater stern shape may be more complex due to the occurrence of stern appendages such as bossings, strut supports and local shape variations. To this extent, CFD offers an effective tool for both qualitative as well as quantitative assessment of the local geometry. Wake estimate is required for choice of the most favorable propeller geometry. In the present method, the analysis quantifies the effects of small changes in stern rake angles and offers an inverse design approach towards finalising the stern shape. The method consists of solving the standard k-ε turbulent model of RANS equations in cell centered finite volume multi zone grid in the flow domain. This approach has been used in estimating the velocity at the propeller plane. The results have been compared with experimentally obtained values of nominal wake. The approach suggests that CFD can provide a cost effective and quick assessment of flow. It is also an attractive means of pre-empting heterogeneous flow related problems such as vibration and noise due to unfavorable wake in the stern region.     

水下采油树设计影响参数分析

通过分析不同类型水下采油树的特点及其优缺点,提出水下采油树设计时所需的主要参数。采油树的类型应根据不同的油田开发模式进行选择,在此基础上再制定水下采油树的整体设计方案。综合考虑水深、油藏的特性、井口装置的型式和采油作业的方式等方面的因素,在保证水下采油树强度、稳定性的条件下,进行具体的结构设计、流动保障设计、热绝缘设计、防腐设计和密封设计。同时,为确保水下采油树的安全性和可靠性,需要特别考虑水下采油树的材料问题,并进行可靠性分析和风险分析。     

在AutoCAD平台上应用ActiveX技术进行船体曲面造型

论述了AutoCAD ActiveX Automation,并就应用Active技术进行二次开发AutoCAD的问题，讨论了如何引用对象和使用对象的方法和属性、使用文档对象的事件、用ADO（ActiveX Data Objects)开发基于数据库的应用程序等。通过应用ActiveX技术，在AutoCAD中构造了船体曲面。     

A mixed continuous and discrete nonlinear constrained algorithm for optimizing ship hull structural design

A nonlinear search algorithm for optimizing constrained design of ship structures is presented. The decision variables can be continuous or discrete and the constraints can be homogeneous or inequality nonlinear functions of those variables. The algorithm does not use gradients; therefore, it can work with non-systematized functions such as tables or another class of design routine. It was tested in the structural design of a Patrol Boat and has proved to be a powerful tool decreasing the time expended in preliminary design when it is done by the conventional spiral approach.     

耐压柱壳参数化设计与灵敏度分析

为提高耐压柱壳设计效率,设计了耐压柱壳参数化分析流程。研究了有限元分析所涉及的材料属性、载荷施加、边界条件设置等内容,确定了采用弧长法分析耐压柱壳稳定性。利用Python语言对于ABAQUS软件进行了二次开发,利用Isight软件实现了ABAQUS的集成,实现了耐压柱壳有限元分析模型的网格自动划分、自动分析计算等。选择样本点进行参数化分析,利用响应面模型对于样本点进行了拟合,得到了具有较高拟合精度、满足工程需要的近似模型,进行了设计变量的灵敏度分析。研究结果表明:参数化分析流程可实现耐压柱壳的自动分析、近似模型及灵敏度分析,可降低耐压柱壳分析难度,均可提高耐压柱壳设计效率。     

船体曲面几何表达及水动力性能计算的NURBS方法

采用非均匀有理B样条(NURBS)对船体曲面形状进行几何表达,所生成的网格直接用于后续的有关船体水动力性能计算工作中。对Wigley船型的线性兴波阻力和斜航操纵运动的船体,结合近似的Kutta条件作了相应的数值计算,从与试验结果的比较来看,该方法具有较好的工程精度,对船舶及海洋工程领域中的计算机辅助设计(CAD)与计算流体动力学(CFD)之间的相互集成,具有推动与促进作用。     

海洋电缆弯曲加强器参数化设计与分析

为建立海洋电缆弯曲加强器参数化设计方法,使用有限元模型进行了弯曲加强器设计参数研究.基于海缆及其弯曲加强器的几何结构及受力特点,建立了基于多相耦合梁单元的平面有限元模型,可以计算并分析海缆及其弯曲加强器在一定角度的张力作用下的形变与等效应力分布.通过多个案例系统性地分析了弯曲加强器的主要设计参数,即根部直径、锥体段长度及材料弹性模量,对海缆弯曲挠度、曲率及等效应力分布的影响.文中原创性地提出了弯曲加强器组合设计参数φ(t,L,E).通过定量分析确定了其与海缆最大曲率之间的近似线性关系,并由此设计了参数化的弯曲加强器设计流程.通过设计实例验证了组合参数与海缆最大曲率之间关系的准确性和参数化设计流程的有效性.     

船体可靠性评估

为了研究不同结构船体的寿命和使用时可靠度的关系,提出了一种基于试验的可靠度估计方法.针对不同结构船体寿命服从Weibull分布,在无失效数据情形下、置信度至少为γ和寿命为t时,根据船体寿命试验数据,给出了可靠度的单侧置信下限.该方法是在Weibull分布形状参数下限已知的情况下,能将所有的无失效寿命数据进行累加,大大提高了可靠性分析的精度.最后,对钢结构、钛合金结构、铝合金结构的船体,在寿命为t月、置信度至少为γ时,计算了3种结构船体的可靠度单侧置信下限.结果表明该方法易于计算,便于工程应用.     

Development of BOATDSS high speed boat design database

Yachts and recreational boats have been growing in popularity throughout the world. In the United States alone they have a 2% annual growth rate. This growth has created the market for new boats built with improved hull materials and new hull forms, propulsion motors and fabrication techniques. With this growth in boat designs and technology developments, it is useful to examine the current trends in pleasure boat design. This paper addresses the development and utilization of a relational pleasure boat database BOATDSS–Boat Decision Support System. The BOATDSS database contains the data on 850 boat designs. The Decision Support System portion of the BOATDSS is organized to use this data for decision support such as a buyer shopping or a builder examining the potential of a new boat entering the present boat market. Several results from BOATDSS are presented to illustrate its use during the conception and preliminary design of recreational boats.     

虚拟仿真技术在帆船运动中的应用研究

根据天气和海况对帆船训练和比赛的影响,通过对帆船的受力分析,建立帆船受力的动力学模型,借助虚拟现实技术,可以预设不同的比赛环境,实现对帆船运动的模拟仿真,辅助帆船日常训练和竞技分析。     

Parametric Geometric Model and Hydrodynamic Shape Optimization of A Flying-Wing Structure Underwater Glider

Combining high precision numerical analysis methods with optimization algorithms to make a systematic exploration of a design space has become an important topic in the modern design methods. During the design process of an underwater glider''s flying-wing structure, a surrogate model is introduced to decrease the computation time for a high precision analysis. By these means, the contradiction between precision and efficiency is solved effectively. Based on the parametric geometry modeling, mesh generation and computational fluid dynamics analysis, a surrogate model is constructed by adopting the design of experiment (DOE) theory to solve the multi-objects design optimization problem of the underwater glider. The procedure of a surrogate model construction is presented, and the Gaussian kernel function is specifically discussed. The Particle Swarm Optimization (PSO) algorithm is applied to hydrodynamic design optimization. The hydrodynamic performance of the optimized flying-wing structure underwater glider increases by 9.1%.     

Hydrodynamic optimization of ship hull forms

An extremely simple CFD tool is used to compare the calm-water drags of a series of hull forms and to define ‘optimized’ monohull ships for which the total (friction+wave) calm-water drag is minimized. The friction drag is estimated using the classical ITTC formula. The wave drag is predicted using the zeroth-order slender-ship approximation. Comparisons of theoretical predictions and experimental measurements for a series of eight hull forms show that—despite the extreme simplicity of the method that is used here to estimate the friction drag and the wave drag—the method is able to rank the drags of a series of hull forms roughly in accordance with experimental measurements. Thus, the method may be used, with appropriate caution, as a practical hull form design and optimization tool. For purposes of illustration, optimized hull forms that have the same displacement and waterplane transverse moment of inertia as the classical Wigley hull, taken as initial hull in the optimization process, are determined for three speeds and for a speed range.