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China Ocean Engineering 2024年第1期38卷 81-92页

作者： LIAO Xi-yu XIA Jin-song CHEN Zhan-yang TANG Qin ZHAO Nan ZHAO Wei-dong GUI Hong-bin Marine Design&Research Institute of China Shanghai 200011China Ship Structure Division China Ship Scientific Research CenterWuxi 214082China College of Ocean Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China School of Foreign Studies Jiangnan UniversityWuxi 214122China

To predict the wave loads of a flexible trimaran in different wave fields,a one-way interaction numerical simulation method is proposed by integrating the fluid solver(Star-CCM+)and structural solver(Abaqus).Differing from the existing coupled CFD-FEA method for monohull ships in head waves,the presented method equates the mass and stiffness of the whole ship to the hull shell so that any transverse and longitudinal section stress of the hull in oblique waves can be ***,verification study and sensitivity analysis are carried out by comparing the trimaran motions using different mesh sizes and time step *** on the wave elevation of uni-and bi-directional waves is also carried *** a comprehensive analysis on the structural responses of the trimaran in different uni-directional regular wave and bi-directional cross sea conditions is carried out,***,the differences in structural response characteristics of trimaran in different wave fields are *** results show that the present method can reduce the computational burden of the two-way fluid-structure interaction simulations.

关键词： CFD-FEA fluid-structure coupling structural responses trimaran bi-directional cross sea

Numerical Prediction of Form Factor and Wave Interference of A trimaran for Different Outrigger Positions

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China Ocean Engineering 2022年第2期36卷 279-288页

作者： Ali DOGRUL Burak YILDIZ Department of Naval Architecture and Marine Engineering Turkish Naval AcademyNational Defense UniversityIstanbul 34940Turkey Department of Marine Engineering Operations Yildiz Technical UniversityIstanbul 34349Turkey

trimaran hydrodynamics have been an important research topic in recent *** have even been chosen for naval surface *** this case,investigation of a trimaran with different outrigger positions is important and necessary for better hydrodynamic *** paper focuses on the numerical investigation of trimaran *** trimaran model used in this study is a 1/80 scale high-speed displacement frigate-type concept developed by the Center for Innovation in Ship Design(CISD)at Naval Surface Warfare Center,Carderock Division(NSWCCD).The numerical simulations were conducted for different outrigger positions at low and moderate Froude numbers by using commercial CFD software solving URANS equations.A verification and validation study was carried out for the numerical method in one configuration and one ship *** existing experimental results for the trimaran resistance in the literature were used for *** different outrigger positions were analyzed and the form factor of each configuration was calculated by the Prohaska *** total resistance was decomposed to its components using the form *** interference factor was calculated for each configuration in terms of total resistance,residual resistance and wave ***,wave profiles using the longitudinal wave cuts in different locations were obtained both numerically and *** was concluded that the outrigger position had different effects on the interference,total resistance and wave profile at different Froude *** was also shown that the CFD results were in good agreement with the experimental data in all *** conclusion,this study presents the results of interference effects for different trimaran configurations in terms of wave resistance in addition to the total resistance and residual *** numerical method was validated not only with the total resistance test data but also the longitudinal wave profiles a

关键词： CFD form factor wave interference wave profile outrigger trimaran

A NUMERICAL STUDY ON SIDE HULL OPTIMIZATION FOR trimaran

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Journal of Hydrodynamics 2011年第2期23卷 265-272页

作者： XU Min ZHANG Shi-lian State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China

Due to the interaction between the main hull and side hulls, different layouts and lengths of side hulls affect the wave loads significantly. Based on three-dimensional potential theory and Green＇s function, this article gives the significant values for wave loads, including vertical shear forces and vertical bending moments at different locations on the main hull, and transverse bending moments at the junction of the cross structure and main hull. In addition, a parametric optimization of wave loads for different layouts and lengths of side hulls were perfomed. Several speeds and wave headings were also considered. Finally, spectral analysis was conducted to attain load distribution. The conclusions of this study are conducive to the design and optimization of this new type of ship

关键词： trimaran three-dimensional potential theory wave loads optimization

STUDY OF trimaran WAVEMAKING RESISTANCE WITH NUMERICAL CALCULATION AND EXPERIMENTS

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Journal of Hydrodynamics 2002年第2期14卷 99-105页

作者： Li Pei-yong, Qiu Yong-ming, Gu Min-tong School of Naval Architecture and Ocean Engineering, Shanghai Jiaotong University, Shanghai 200030, China School of Naval Architecture and Ocean Engineering Shanghai Jiaotong University Shanghai 200030 China

Based on the potential flow assumption, this paper outlines the formulation of the boundary-value problem governing the steady free surface flow around a trimaran advancing at a constant forward. A Rankine panel method was developed for the solution of the problem. The side-hulls were treated as lifting bodies and circulation was introduced into the flow field to implement the asymmetrical flow around each side hull. The linearized free surface condition was used. The appropriate treatment for transom-stern ship was also discussed. Additionally, a test was performed to quantify the resistance and especially the interference between the main and side hulls. The numerical results are in good argeement with experimental data.

关键词： trimaran wavemaking panel method model test

NUMERICAL SIMULATION OF WAVE RESISTANCE OF trimaranS BY NONLINEAR WAVE MAKING THEORY WITH SINKING AND TRIM BEING TAKEN INTO ACCOUNT

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Journal of Hydrodynamics 2011年第2期23卷 224-233页

作者： WANG Zhong LU Xiao-ping College of Naval Architecture and Power Naval University of Engineering Wuhan 430033 China

Up to now, there are no satisfactory numerical methods for simulating wave resistance of trimarans, mainly due to the difficulty related with the strong nonlinear features of the piece hull wave making and their interference. This article proposes a numerical method for quick and effective calculation of wave resistance of trimarans to be used in engineering applications. Based on Wyatt＇s work, the nonlinear free surface boundary condition, the time domain concept, and the full nonlinear wave making theory, using the Rankine source Green function, the 3-D surface panel method is expanded to solve the trimaran wave making problems, with high order nonlinear factors being taken into account, such as the influence of the sinking and trim, transom, and ship wave immersed hull surface. And the software is successfully developed to implement the method, which is validated. Several trimaran models, including a practical trimaran with a sonar dome and the transom, are used as numerical calculation samples, their wave making resistance is calculated both by the present method and some other methods such as linear （Dawson） methods. Moreover, sample model resistance tests were carried out to provide data for comparison, validation and analysis. Through the validation by model experiments, it is concluded that present method can well predict the wave making resistance, sinking and trim, and the accuracy of wave making resistance calculation is significantly improved by taking the trim and sinking into account, especially at high speeds.

关键词： trimaran nonlinear wave making resistance surface panel method sinking trim ship model test

WAVE MAKING COMPUTATION IN TIME DOMAIN FOR MULTI-HULL SHIPS

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Journal of Hydrodynamics 2006年第2期18卷 225-230页

作者： LI Guo-an YE Heng-kui School of Traffic Science and Engineering Huazhong University of Science and Technology Wuhan 430074China

A method Green function satisfying of three-dimensional time domain 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 tbr 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.

关键词： time domain Green function ship wave making mono-hull catamaran trimaran

Hydrodynamic optimization of a triswach

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Journal of Hydrodynamics 2014年第6期26卷 856-864页

作者： YANG Chi HUANG Fuxin KIM Hyunyul School of Physics Astronomy and Computational Sciences George Mason University NAVATEK South KingstownRI 02879USA

A new methodology for hydrodynamic optimization of a Tri SWACH is developed, which considers not only the positions of the side hulls but also the shape of the side hulls. In order to account for the strong near-field interference effects between closely-spaced multihulls, an integrated hydrodynamic computational tool that consists of a potential-flow based simple CFD tool and an Euler/RANS/Navier-Stokes based advanced CFD tool has been further developed and integrated into a practical multiobjective hydrodynamic optimization tool. The other components of this hydrodynamic optimization tool consist of a hull shape representation and modification module and an optimization module. This enhanced multi-objective hydrodynamic optimization tool has been applied to the hydrodynamic design optimization of the Tri SWACH for reduced drag by optimizing the side hulls only. A new methodology is developed to optimize side hull forms so that the Tri SWACH has a minimal drag for a wide speed range and for various side hull positions. Two sets of the side hulls are developed and used for the design of two optimal Tri SWACH models. Model tests are carried out for two optimal Tri SWACH models at Webb Institute for validations. Substantial drag reductions have been obtained for a wide range of speed.

关键词： hydrodynamics optimization drag reduction CFD trimaran surface modification

OPTIMIZATION OF A WAVE CANCELLATION MULTIHULL SHIP USING CFD TOOLS

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Journal of Hydrodynamics 2002年第1期14卷 1-7页

作者： C. Yang, R. L■hner, O. Soto (School of Computational Sciences, George Mason University Fairfax VA 22030-4444, USA) Sch. of Comp. Sci. George Mason Univ. Fairfax VA 22030-4444 United States

A simple CFD tool, coupled to a discrete surface representation and a gradient based optimization procedure, is applied to the design of optimal hull forms and optimal arrangement of hulls for a wave cancellation multihull ship. The CFD tool, which is used to estimate the wave drag, is based on the zeroth order slender ship approximation. The hu ll surface is represented by a triangulation, and almost every grid point on the surface can be used as a design variable. A smooth surface is obtained via a si mplified pseudo shell problem. The optimal design process consists of two steps . The optimal center and outer hull forms are determined independently in the fi rst step, where each hull forms are determined independently in the first step, where each hull keeps the same displacement as the original design while the wav e drag is minimized. The optimal outer hull arrangement is determined in the se cond step for the optimal center and outer hull forms obtained in the first step . Results indicate that the new design can achieve a large wave drag reduction i n comparison to the original design configuration.

关键词： hull form design hull form optimiza tion wave cancellation multihull ship trimaran wave resistance CFD tools sl ender ship approximation surface parameterization.

Numerical Simulations of Viscous Flow around Multi-Hull Ship by Overset Grid Techniques

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Numerical Simulations of Viscous Flow around Multi-Hull Ship...

面向可重构SoC的应用程序特征分析方法研究与实现

第十五届中国海洋（岸）工程学术讨论会

作者： Shen Zhirong,Ma Juan,Wan Decheng (State Key Laboratory of Ocean Engineering,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240)

Since multi-hull ship has good resistance and seakeeping performances in sea waves as well as a bigger deck area compared with the ordinary mono-hull ship,it has been applied not only for civil use but also for *** present work,numerical simulation of viscous flows around two common types,catamaran and trimaran,based on RANS method coupled with overset grid technique and level set method,is *** free-surface is taken into account and treated by level-set *** grid technique is employed to embed the body-fit hull grids into an orthogonal background *** distance gap between ship hulls can be adjusted easily by the overset grid technique without regenerating the mesh,such that the optimal distance gap between ship hulls can be figured *** for each distance gap,a serial of calculation with different Froude numbers is carried out to predict the resistance characteristics and find out the optimal distance gap and ship hull *** also includes the complex wave patterns produced by the multi-hull ship.

关键词： Catamaran trimaran overset grid Level-set resistance

来源： cnki会议评论

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面向可重构SoC的应用程序特征分析方法研究与实现

作者：杜春洁国防科学技术大学

学位级别：硕士

随着面向特定应用领域的计算需求不断增大，可重构SoC由于具有结构的灵活性和计算的高效性而得到了广泛的关注，成为了当前计算机体系结构研究的一大热点。可重构SoC设计的主要目标是能够高效的运行面向特定领域的应用程序，故其具有面... 详细信息

随着面向特定应用领域的计算需求不断增大，可重构SoC由于具有结构的灵活性和计算的高效性而得到了广泛的关注，成为了当前计算机体系结构研究的一大热点。可重构SoC设计的主要目标是能够高效的运行面向特定领域的应用程序，故其具有面向领域应用的特性。因此对可重构SoC专用应用领域的应用程序特征的研究对于设计出高性能的可重构SoC具有重要意义。本文紧紧围绕可重构SoC设计的专用指令集定制、任务划分与分配、应用映射的需求，研究应用领域的程序特征分析方法及其实现。本文主要完成的工作及取得的研究成果如下： 1、设计了一种面向可重构SoC的动态仿真与静态分析相结合的应用程序特征分析方法架构。该方法框架面向可重构SoC设计的需求基于应用程序的中间表示建立程序的特征模型，因此该分析方法框架能够更加关注与可重构SoC设计过程联系紧密的程序特征。 2、本文基于trimaran的中间表示和模拟器进行自动化的应用程序特征分析，设计和实现了基本程序特征的分析方法。包括：程序结构特征分析、控制流分析、计算特征分析、操作数特征分析、执行时间分析、数据活跃性分析等。实验结果表明该方法能够很好的分析出程序的基本特征，用于指导专用指令集设计，程序任务分配等过程。 3、提出和实现了一种基于执行时间和工作量估算相结合的核心循环识别与提取方法。该方法对循环体的工作量进行了估计，用于指导核心循环的识别和提取。在可重构SoC设计过程中，不同的设计过程关注的核心循环的特征不一样，本方法根据可重构SoC设计人员关注的核心循环特征信息的需求不同，将会产生不同的核心循环识别因子，进而提取出与特征需求联系更加紧密的核心循环，更好的指导其相关设计过程。 4、提出和实现了一种循环层次树形图的构建方法。该图能够清晰的反映出循环的嵌套层次关系，从而使可重构SoC设计人员可以比较直观的了解应用程序的循环的嵌套关系。此外，该循环层次树形图很好的支持了核心循环的识别与提取过程和嵌套循环间的数据相关性分析。 5、提出和实现了一种基于依赖强度表示的基本块粒度数据依赖图的构建方法。通过该方法构建的基本块数据依赖图可以反映一个基本块与其他基本块之间的相关强弱关系，有助于系统设计人员进行编译映射和优化以及任务分配。

关键词：可重构 SoC 程序特征分析循环 trimaran Elcor 中间表示