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EXPERIMENTAL STUDY OF EFFECTS OF AIR CONTENT ON CAVITATION AND PRESSURE FLUCTUATIONS

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Journal of Hydrodynamics 2010年第5期22卷 634-638页

作者： YE Jin-ming XIONG Ying LI Fang CHEN Shuang-qiao College of Naval Architecture and Power Naval University of Engineering Wuhan 430033 China

This article studies the effects of air content on propeller cavitation and pressure fluctuations. The cavitation is observed while the pressure fluctuations on the hull are measured. When adjusting the air content, the sheet cavitation range does not change distinctly, but the pressure fluctuations see obvious differences. The amplitudes of the pressure fluctuations increase with the decrease of the air content. The results indicate that the air content has little effect on the sheet cavitation range but has an important effect on the bubble cavitation and the tip vortex cavitation. When the air content decreases, the water tensile force increases, which results in the instability of the bubble cavitation and the tip vortex cavitation and the increase of the pressure fluctuations. To minimize the scale effects, the experiments should be run at a high Reynolds number with a high nuclei content. The high Reynolds number is often realized by increasing the flow velocity and the propeller rotation speed, and the high nuclei content is often made by increasing the dissolved air content.

关键词： cavitation pressure fluctuations model test air content

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基于局域支持向量机的海浪水压场混沌预测

系统仿真学报 2008年第23期20卷 6470-6472,6476页

作者：单志超林春生向前海军工程大学兵器工程系湖北武汉430033 海装武汉局701代表室湖北武汉430000

针对海浪水压场的短时平稳性,采用局域支持向量机进行预测滤波。首先分析了海浪水压场信号的混沌特性,并根据其混沌特性,提取训练空间中与当前相点的行为特征密切相关的最近邻点作为训练样本对支持向量机进行训练,减少了训练样本的数目... 详细信息

针对海浪水压场的短时平稳性,采用局域支持向量机进行预测滤波。首先分析了海浪水压场信号的混沌特性,并根据其混沌特性,提取训练空间中与当前相点的行为特征密切相关的最近邻点作为训练样本对支持向量机进行训练,减少了训练样本的数目,节省了网络学习时间,从而可实时对网络参数进行更新,使支持向量机能够跟随海浪的变化。实际计算表明这种算法能够以较快的学习速度和较高准确度实现海浪预测,能够克服由于海浪的短时平稳性所带来的随时间的增长预测精度下降的问题。

关键词：海浪水压场支持向量机混沌预测短时平稳

BEZOUT FACTORS AND L~1-OPTIMAL ROBUST CONTROLLERS DESIGN FOR MIMO INPUT DELAY SYSTEMS

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BEZOUT FACTORS AND L~1-OPTIMAL ROBUST CONTROLLERS DESIGN FOR...

第七届国际信号处理会议

作者： He Hanlin (Culture and Science College Naval University of Engineering Hubei Wuhan 430033 China) Email: hanlinhe62@***

This paper, using the normalized coprime factors of ?nite-dimensional systems in the L2 setting, gives the normalized coprime factors of in?nite-dimensional causal strictly proper input delay syste

关键词： Bezout factors Input delay system Optimal ro- bust stabilization Robust controller.

Theoretic Analyses and experimental study in nonlinear rolling motion of a flooded ship in waves

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Theoretic Analyses and experimental study in nonlinear rolli...

2002年安全与科学技术国际会议

作者： PU Jinyun CHENG Xiaohong & ZHOU Renbin (Power Engineering College Naval University of Engineering Wuhan 430033 China)

＜正＞ A flooded ship can exhibit undesirable non-linear rolling motion, even in waves of moderate amplitude. In order to understand the mechanism of this non-linear phenomenon, it must be considered that the liquid cargo carried in the second kind and the third kind flooded compartment and its free surface can exert influence on moment of inertia, added mass, rolling damping and return moment, The stability condition and the "jump phenomenon" of this coupled system is described. The influence of the flooded tank on hydrodynamic characteristics of flooded ship is also been explored.

关键词： Theoretic Analyses experimental study non-linear roll motion flooded ship

Portable Fault Diagnostics Facility of Corresponding Equipments

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Portable Fault Diagnostics Facility of Corresponding Equipme...

2007 8th International Conference on Electronic Measurement & Instruments（ICEMI’2007）

作者： Chen Bin Wang Yongbin Li Juan Cao xufeng (Naval University of Engineering,Wuhan,430033,China)

This facility clearly diagnosticates malfunctions of corresponding equipments and provides data accurately and *** are many virtues in this facility,such as: convenience use,simple operation,practicability,strong function,high intelligence and automatization,and so *** can quickly and accurately diagnostics malfunctions with the help of the new nerve network expert system,so the time to discover and repair faults has been shorten *** facility is mainly used for quickly examining and rushing to repair of corresponding equipments.

关键词： Portable Fault Diagnostics Corresponding PXI

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闭式燃气轮机回热循环性能新析

太阳能学报 1995年第4期16卷 447-448页

作者：陈林根孙丰瑞海军工程学院

导出存在热阻和不可逆压缩、膨胀损失的闭式燃气轮机回热循环功率和效率与压比间的解析式，发现回热对循环功率有较大影响。

关键词：有限时间热力学闭式燃气轮机回热循环最优化

Modeling and simulation on accuracy of broad band acoustic Doppler current profiler

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Modeling and simulation on accuracy of broad band acoustic D...

Asia Simulation conference 2008/the 7th International Conference on System Simulation and Scientific Computing（ICSC‘2008）

作者： HUANG Xiong-fei,Department of Weapon Engineering.,Naval University of Engineering,Hubei Wuhan 430033,China. YUAN Bing-cheng,Department of Weapon Engineering.,Naval University of Engineering,Hubei Wuhan 430033,China

Broad band acoustic Doppler current profiler (BBADCP) adopt repeated binary coded pulse as it's transmitted signal. According to the characteristic of signal spectrum, this kind of signal can be represented as the linear addition of multiple narrow band signals with different frequency. Using the Cramer-Rao bound of narrow band acoustic Doppler current profiler (NBADCP), the accuracy model of BBADCP is established and simulation is done. The reason that accuracy of BBADCP is higher than NBADCP is analyzed, and the conditions that accuracy of BBADCP is higher than NBADCP are discussed, at the same time, the relationship of measurement precision, Signal-to-Noise and the length of codes are analyzed. At last, some principles of selection of signal parameters are presented.

关键词： Modeling and simulation on accuracy of broad band acoustic Doppler current profiler Doppler simulation

PERFORMANCE OPTIMIZATION OF A GENERALIZED IRREVERSIBLE CARNOT ENGINE WITH A GENERALIZED HEAT TRANSFER LAW

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PERFORMANCE OPTIMIZATION OF A GENERALIZED IRREVERSIBLE CARNO...

国际能源转换及利用学术会议

作者： Zhou Shengbing Chen Lingen Sun Fengrui Naval University of Engineering Wuhan 430033 P. R. China

This paper presents a generalized irreversible Carnot engine model that incorporates several internal and external irreversibilities. The added irreversibilities besides heat resistance are characterized by a constant parameter and a constant coefficient. The relation between optimal power output and efficiency is derived based on a generalized heat transfer law q(△T). Detailed numerical examples show the effect of heat leakage, internal irreversibility and heat transfer law on the optimal performance of the generalized irreversible heat engine.

关键词： finite time thermodynamics heat engine performance optimization

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三相可控整流桥系统共模干扰研究

中国电机工程学报 2005年第2期25卷 40-43页

作者：张磊马伟明海军工程大学电力电子研究所湖北省武汉市430033

根据整流桥干扰产生的原理，计算了三相整流桥的共模干扰源，并结合按军标GJB152A-97建立的测试系统进行了分析，得到了计算共模干扰电流的等效电路。利用频域法对一个三相可控整流桥产生的共模干扰电流进行了计算，并与实验结果进行了... 详细信息

根据整流桥干扰产生的原理，计算了三相整流桥的共模干扰源，并结合按军标GJB152A-97建立的测试系统进行了分析，得到了计算共模干扰电流的等效电路。利用频域法对一个三相可控整流桥产生的共模干扰电流进行了计算，并与实验结果进行了比较，实验结果证实了计算的有效性。

关键词：变流器整流器三相可控整流桥系统共模干扰等效电路