2009 Vol. 4, No. 5

Characters of Sound Balance from Multi-support Excited Ship Hull
Yao Xiongliang, Ji Fang
2009, 4(5): 1-7. doi: 10.3969/j.issn.1673-3185.2009.05.001
Abstract:
Based on the theory of ship fluid-structure-sound coupling interaction, the engineering three dimensional program was explored to compute the entrained water mass of ship wet mode on the basis of Potential Flow Theor y. The calculated results were compared with the theoretical value, empirical value and numerical value of FEM to verify the validity and rationality of the program. A method of "sound balance" was proposed to analyz ze the coupling vibration of hull-base-equipment which is excited by ship-equipment-paddle as well as underwater sound radiation. The results show that the sound pressure of stem with engine location takes on peak-to-v alley tendency, which can be reduced through the optimum matching site. As for the selection of ships" main and auxiliary engines, the sound balance of hullbase-equipment as well as that of equipment needs to be con nsidered, and this method must give attention to multi-support excitation force ratio and the frequency ratio. This article aims to provide reference for acoustic design of hull structure.
子结构方法在圆柱壳体振动特性分析中的应用研究
Wang Xueren, Miao Xuhong, Jia Di
2009, 4(5): 8-13,19. doi: 10.3969/j.issn.1673-3185.2009.05.002
Abstract:

针对大型复杂结构振动特性的预测问题,发展了一种子结构方法,并应用于圆柱壳模型的振动特性研究。圆柱壳模型长4.2m,直径0.4m,由5部分组成,并且在第4和第5部分内有一个轴系结构。用子结构方法研究其振动特性时,模型被分为3个子结构,子结构间通过螺栓进行连接。因此,首先介绍了子结构方法及连接处理方式的理论基础,然后通过实验验证了发展方法的正确性,并着重分析了子结构模态综合阶数和连接处理方式对整体结构预测结果的影响规律,最后对比分析了子结构方法与传统有限元法对计算量和内存量的要求。结果表明:发展的子结构方法具有较高的精度,可应用于求解船舶等大型复杂结构的振动特性。

A Hybrid Method for Interior Structural-acoustic Analysis
Peng Weicai, Zhao Gaoyu, He Zeng
2009, 4(5): 14-19. doi: 10.3969/j.issn.1673-3185.2009.05.003
Abstract:
The finite element method (FEM) is a widely accepted prediction tool for the steady-state dynamic response analysis of coupled structural-acoustic (SA) systems. However, it is limited to the low frequency range d ue to the fast growing model size for increasing frequencies. An alternative method is the wave based method (WBM) based on the indirect Trefftz method. However, the applicability of the WBM is limited since the high h computational efficiency only appears for moderate geometrical complexity. In order to take advantage of the wide application range of the FEM and the high convergence rate of the WBM, a hybrid method of the two is p roposed. The basic idea is to replace parts of the FE model with simple geometrical shapes by much smaller wave models. The resulting hybrid model has fewer degrees of freedom. The theoretical background of both the FE M and the WBM is briefly discussed, followed by the mathematical description of the hybrid FE-WB method. The hybrid modeling concept is demonstrated for a structural-acoustic system. The results are shown to be in good agreement with numerical simulation results. The example illustrates that the hybrid FE-WB method has the potential to cover the mid-frequency range.
舰船舱段模型在水下爆炸作用下的壁压分析
Fan Baoshun, Cheng Suqiu, Han Feng
2009, 4(5): 20-22. doi: 10.3969/j.issn.1673-3185.2009.05.004
Abstract:

对舰船舱段模型进行了海上水下爆炸试验,试验的目的是测试药包处于不同水下深度时,舱段模型龙骨处冲击载荷的差别。试验时,测量了自由场压力和壁压。根据试验结果,给出了自由场压力与壁压实测曲线。同时,采用正向超压时间计算公式,和实测自由场冲击波长超压时间以及自由场压力峰值与壁压峰值进行了对比。最后利用matlab软件对自由场压力和壁压进行了定性分析。试验结果对海上水下爆炸理论分析和今后的海上水下爆炸试验均有一定参考价值。

舰船舰面空气流场的CFD数值模拟探讨
Qu Fei, Lu Chao, Jiang Zhifang, Wang Tao
2009, 4(5): 23-27. doi: 10.3969/j.issn.1673-3185.2009.05.005
Abstract:

CFD技术已经广泛应用于舰船水流场的分析计算研究领域,而在舰船空气流场研究中的应用趋势正在逐步增强,目前国内在该领域的研究工作还处于起步阶段。从现代舰船气流场的研究发展现状、舰船空气流场CFD数值计算方法的选用以及实例数值计算,探讨了数值模拟舰船气流场的可行性,并通过将计算实例的数值计算结果与其对应状态的风洞试验结果进行对比分析,验证了计算结果的合理性,结果显示,利用CFD工具在定常条件下对舰船空气流场的模拟计算方法是可行的。

三体船兴波阻力计算方法比较及兴波干扰研究
Liu Changmin, Li Yunbo, Li Yulong
2009, 4(5): 28-32. doi: 10.3969/j.issn.1673-3185.2009.05.006
Abstract:

分别利用Noblesse细长船理论和薄船理论,以Wigley三体船为例计算傅汝德数在0.20~0.70范围内多个侧体布局下的兴波阻力,探讨三体船两个侧体间和3个侧体之间的兴波干扰,得到对三体船设计具有指导意义的结果。通过与试验结果比较表明,基于首阶近似,不考虑线积分项的Noblesse细长船理论兴波阻力系数的计算结果与薄船理论非常相近。考虑线积分项的Noblesse细长船理论兴波阻力系数计算结果小于薄船理论的计算结果,后者量值更接近于试验值,但是两种计算方法的兴波阻力系数曲线凸凹点对应的傅汝德数相近,表明两种计算方法对兴波干扰现象的计算预测是相近的。研究表明,用薄船理论计算三体船的兴波阻力,探讨多体船侧体之间的兴波干扰目前是一种简便、可行的方法。

Experimental Study on Welding Residual Stress of Thick Plate
Huang Jing, Liu Yuguang, Zhang Tao, Xie Fan
2009, 4(5): 33-37,44. doi: 10.3969/j.issn.1673-3185.2009.05.007
Abstract:
With blind-hole drilling method, the welding residual stress of thick plate was measured under different welded joint types, plate thickness, and welding processes. Considering the plasticity effect, the distribution of welding residual stress in thick plate was obtained. Then, the effects of joint types, plate thickness, welding process, and groove dimensions on the welding stress distributions were discussed. The results show th at: unconstrained structure can reduce the residual stress, and welding sequences adjustment can change the position of residual stress peak values, and proper groove dimensions can effectively reduce the effects of w welding residual stress on the structure strength.
Evaluation Method for Structural Strength of Asymmetric Double Tube Sheet of Marine Condenser
Xu Shanshan, Zhang Aman, Xie Jinxin, Li Shiming
2009, 4(5): 38-44. doi: 10.3969/j.issn.1673-3185.2009.05.008
Abstract:
With the development of industrial equipment, double tube condenser of asymmetric shells has been widely used, and traditional design standards are not suitable for strength evaluation of such structures. In this pap er, a model of an asymmetric double tube is developed by general-purpose commercial finite element analysis software HyperMesh and ABAQUS. Considering the work condition of tube pressure, shell pressure and combination of the two, a new checking method is proposed to evaluate the strength of asymmetric double tube shells. The result shows that the proposed way is efficient and feasible with thorough understanding and improved accura cy.
CODOG监控系统电路板自动测试技术研究
Xiao Xinbin, Liu Yongbao, Gao Jianhua
2009, 4(5): 45-48. doi: 10.3969/j.issn.1673-3185.2009.05.009
Abstract:

电路板自动测试技术对于舰用动力装置监控系统的故障检测与维修至关重要。以CODOG动力装置监控系统使用广泛、故障率较高的电路板RA1-01继电器输出板为例,选取BDS—9210柜式VXI自动测试设备作为测试平台,介绍RA1-01的测试程序集(TPS)的开发过程。测试结果表明:TPS故障检测率为95%,故障隔离率为80%(模糊度为4)。

ESD_FT Method in the Analysis of Marine Reactor Water-loss Accident
Ren Xin, Zhao Xinwen, Cai Qi
2009, 4(5): 49-53,58. doi: 10.3969/j.issn.1673-3185.2009.05.010
Abstract:
Event Sequence Diagram (ESD) method is usually used to analyze the accident's development and consequences. However, it is quantitatively insufficient to control the model scale and lack of modeling capability. Fo r the complicated system, model purely produced by ESD method is often too complicated to be intuitive. A hybrid approach is employed which combines ESD with Fault Tree method to produce the model. In this way, it can make full use of the advantages of fault tree analysis techniques and the produced model is more concise and intuitive. This paper explores the application of ESD_FT method in the marine reactor accident analysis, and a new evolving ESD event by inner FF is proposed, and the model marine reactor water-loss accident analysis is established. Finally, happening probability of accident is obtained. The results show that ESD_FT method is more effective and applicable for the accident analysis.
基于SPWM控制的电压、电流双环逆变器建模及其仿真
Zhu Chengbang, Li Le, Wang Xiaopeng
2009, 4(5): 54-58. doi: 10.3969/j.issn.1673-3185.2009.05.011
Abstract:

基于SPWM的电压电流双环逆变器控制相对其他逆变器控制策略具有一定优越性,但其控制器参数设计却是一个重点和难点。针对逆变器的SPWM电压电流双环控制策略,建立了系统的控制模型,设计了电流内环和电压外环的控制器参数,并根据经典控制理论的判据,分别对控制器电流内环和电压外环参数进行了理论验证。最后根据设计的控制器参数,对SPWM电压电流双环控制系统模型进行了仿真分析,结果表明,系统设计合理,效果满意。

网络中心战中信息网络连接优化设计
Xie Hongsheng, Chen Jiong, Ma Xi, Wu Dinggang
2009, 4(5): 59-62,80. doi: 10.3969/j.issn.1673-3185.2009.05.012
Abstract:

通过分析网络中心战的网络结构,考虑小世界网络模型相关理论,定义了网络中心战中信息网络连接收益、连接成本以及连接增益等相关概念,设计了基于小世界网络模型的网络中心战信息网络连接优化设计方法。通过仿真实验,验证了信息网络连接优化设计方法的可行性,给出了获得网络中心战信息网络最优连接性能的方法。

潜艇作战系统战位复用技术初探
Huang Kun, Xu Jun, Min Shaorong
2009, 4(5): 63-66. doi: 10.3969/j.issn.1673-3185.2009.05.013
Abstract:

潜艇作战系统战位复用设计是潜艇作战系统在操控一体化方面的重要体现。战位复用技术有以下一些优点:减少艇员配置;提高潜艇作战系统可靠性;动态扩展作战系统功能;有利于整个潜艇作战系统的维护。描述潜艇作战系统战位复用的内涵,分析潜艇作战系统采用战位复用的必要性。根据潜艇作战系统的典型战位设置,提出未来新型潜艇作战系统战位设置的设想及实现思路。最后分析潜艇作战系统战位复用技术带来的效益。

Re-developing Free! ship Software by Using Delphi
Tu Rong, Chen Shunhuai
2009, 4(5): 67-70. doi: 10.3969/j.issn.1673-3185.2009.05.014
Abstract:
Free!ship as one ship design tool, has been widely utilized due to its robust functions, userfriendly interface and available free use. As for the work of preliminary ship design, it is desirable that it can determin e the ship's principle dimension prior to the completion of ship lines design. Free! ship can not meet this requirement, however, an effort was made to re-develop it on the basis of its original functions and perfect reproduction environment. For this purpose, flexible oil tanker was studied as an example and two modules (i.e. principle dimension regression module and dimension optimization module) were added into the Free! ship p by programming with Delphi to determine the principle dimensions. The development method and procedure are established and they provide a basis for further development and research.
基于OpenGL的雷达显示器仿真
Zhang Jian, Yang Lei, Dong Xiaoming
2009, 4(5): 71-74. doi: 10.3969/j.issn.1673-3185.2009.05.015
Abstract:

雷达显示器仿真是雷达系统仿真的重点和难点。在简要介绍OpenGL技术和雷达显示器的基础上,提出了利用OpenGL对P型雷达显示器进行仿真的思想,详细介绍了余辉扫描和目标点迹的仿真方法。对于余辉扫描,通过数学建模提出了实现途径,并得出了时间衰减常数和扫描周期的计算公式。对于目标点迹,提出了角度换算和目标位置的计算公式,并实现了点迹的余辉效果。结果表明,该方法达到了很好的仿真效果。

往复泵振动和噪声机理分析及减振降噪措施
Yuan Donghong, Hua Suobao, Gu Zehong, Pan Zhengguang, Lu Fei
2009, 4(5): 75-80. doi: 10.3969/j.issn.1673-3185.2009.05.016
Abstract:

介绍了往复泵的特点,并通过对其工作原理、运动、流量和受力等的分析.找出了往复泵产生振动和噪声的主要振源,进而有针对性的提出了往复泵的减振降噪措施,对潜艇舱底泵的改进具有借鉴意义。