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能量耗散效应的多域边界元法(英文) 总被引:1,自引:0,他引:1
段文洋 《船舶与海洋工程学报》2012,11(1):18-23
The wave diffraction and radiation around a floating body is considered within the framework of the linear potential theory in a fairly perfect fluid.The fluid domain extended infinitely in the horizontal directions but is limited by the sea bed,the body hull,and the part of the free surface excluding the body waterplane,and is subdivided into two subdomains according to the body geometry.The two subdomains are connected by a control surface in fluid.In each subdomain,the velocity potential is described by using the usual boundary integral representation involving Green functions.The boundary integral equations are then established by satisfying the boundary conditions and the continuous condition of the potential and the normal derivation across the control surface.This multi-domain boundary element method(MDBEM) is particularly interesting for bodies with a hull form including moonpools to which the usual BEM presents singularities and slow convergence of numerical results.The application of the MDBEM to study the resonant motion of a water column in moonpools shows that the MDBEM provides an efficient and reliable prediction method. 相似文献
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Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non-Uniform Rational B-Spline (NURBS) higher-order panel method in time domain based on the potential theory. A robust and stable improved iterative procedure (Yan and Ma, 2007) for floating bodies is used for calculating the time derivative of velocity potential and floating body motion. An energy dissipation condition based on linear theory adopted by Huang (2011) is developed to consider flow viscosity effects of sloshing flow in nonlinear model. A two-dimensional tank model test was performed to identify its validity. The present nonlinear coupling sway motion results are subsequently compared with the corresponding Rognebakke and Faltinsen (2003)’s experimental results, showing fair agreement. Thus, the numerical approach presented in this paper is expected to be very efficient and realistic in evaluating the coupling effects of nonlinear sloshing and body motion. 相似文献
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Radar cross section(RCS) is the measurement of the reflective strength of a target.Reducing the RCS of a naval ship enables its late detection,which is useful for capitalizing on elements of surprise and initiative.Thus,the RCS of a naval ship has become a very important design factor for achieving surprise,initiative,and survivability.Consequently,accurate RCS determination and RCS reduction are of extreme importance for a naval ship.The purpose of this paper is to provide an understanding of the theoretical background and engineering approach to deal with RCS prediction and reduction for naval ships.The importance of RCS,radar fundamentals,RCS basics,RCS prediction methods,and RCS reduction methods for naval ships is also discussed. 相似文献
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重点围绕城市轨道交通基于通信的列车控制系统(CBTC)技术需求,详细描述了车载子系统核心安全部件—车载ATP列车自动防护单元关键功能(列车状态监督、列车速度曲线生成与监督、列车运行状态报告生成)的工作原理和功能,重点分析了ATP核心硬件设计(核心处理模块、测速模块、应答器通信模块)和软件架构设计,并结合CBTC车载子系统整体技术方案进行了研究与探讨。 相似文献
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