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THE COMPARATIVE STUDY OF VENTILATED SUPER CAVITY SHAPE IN WATER TUNNEL AND INFINITE FLOW FIELD

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Journal of Hydrodynamics 2010年第5期22卷 689-696页

作者： ZHOU Jing-jun yu kai-ping MIN Jing-xin YANG Ming School of Astronautics Harbin Institute of Technology Harbin 150001 China

In order to understand the difference of ventilated supercavity in water tunnel and infinite flow field, 3-D numerical simulations are carried out to obtain the ventilated supercavity in above mentioned conditions based on RANS equations, using the finite volume method and SST turbulence model in the framework of the two fluid multiphase flow model. The numerical method adopted in this article for the infinite flow field and water tunnel experiments is validated by comparing results with those of empirical formulas and experimental data. On this basis the difference between water tunnel experiments and infinite flow field is studied, including the influence of the route loss and the blocking effect in the water tunnel. Finally, some suggestions are made for water tunnel experiments.

关键词： ventilated supercavity two fluid multiphase model ambient pressure viscous effect blocking effect cavitation number

NUMERICAL SIMULATION OF ARTIFICIAL VENTILATED CAVITY

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Journal of Hydrodynamics 2006年第3期18卷 273-279页

作者： JIA Li-ping WANG Cong WEI Ying-jie WANG Hai-bin ZHANG Jia-zhong yu kai-ping School of Astronautics Harbin Instituteof Technology Harbin 150001 China

In order to determine artificial ventilated cavity shape and provide design reference for engineering applications, the shape of ventilated cavity and the drag of underwater body have been numerically simulated with commercial code in this work. Empirical formulas between ventilated cavity shape and cavitation number are obtained under the conditions of zero incidence and similarity shapes of ventilated cavity and vapor cavity have been validated under the same cavitation number. In addition, the relations between change of cavitator incidence and cavity unsymmetry and the relations of between drag and cavity shape have been primarily analysed. Furthermore, the numerical results fit well with the experimental results.

关键词： ventilated cavity numerical simulation,cavity shape

NUMERICAL STUDY OF THE PITCHING MOTIONS OF SUPERCAVITA-TING VEHICLES

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Journal of Hydrodynamics 2012年第6期24卷 951-958页

作者： yu kai-ping ZHANG Guang ZHOU Jing-jun ZOU Wang LI Zhen-wang School of Aeronautics Harbin Institute of Technology

The pitching motions of supercavitating vehicles could not be avoided due to the lost water buoyancy. In order to have some insight for the design of the supercavitating vehicles, the fixed frequency and free pitching motions are investigated. A numerical predicting method based on the relative motion principle and the non-inertia coordinate system is proposed to simulate the free pitching motions of supercavitating vehicles in the longitudinal plane. Homogeneous and two fluid multiphase models are used to predict the natural and the ventilated supercavitating flows. In the fixed frequency pitching motions, a variety of working conditions are considered, including the pitching angular velocities and the supercavity scales and the results are found to be consistent with the available experimental results in literature. The mesh deformation technology controlled by the moment of momentum equation is adopted to study the free pitching motions and finally to obtain the planing states proposed by Savchenko. The numerical method is validated for predicting the pitching motions of supercavitating vehicles and is found to enjoy better calculation efficiency as comparing with the mesh regeneration technology.

关键词： supercavitating flow two fluid multiphase flow model homogeneous model pitching motion mesh deformation

EXPERIMENTAL RESEARCH ON THE SHAPE CHARACTERS OF NATURAL AND VENTILATED SUPERCAVITATION

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Journal of Hydrodynamics 2007年第5期19卷 564-571页

作者： ZHANG Xue-wei WEI Ying-jie ZHANG Jia-zhong WANG Cong yu kai-ping School of Astronautics Harbin Institute of Technology Harbin 150001 China

A series of projectile and water-tunnel experiments were conducted to investigate the shape characters of natural and ventilated supercavitation. It was found that the shape and dimensions of both the natural supercavitation and the ventilated supercavitation are similar through the comparison of them when the cavitation number is small and equal, and the contour of both the natural supercavitation and the ventilated supercavitation can be calculated effectively with the Savchenko formula. The gravity effect can induce the asymmetry of ventilated supercavitation, and the asymmetry is more apparent as the Froude number is smaller. The empirical formula for calculating the axial deformation of ventilated supercavitation was corrected and expanded based on experiment data. The evolution rules of both the natural supercavitation and the ventilated supercavitation were described, and the vortex frequency of natural cavitation was obtained. In addition, the hysteretic aspect was observed between the development and the fall process of ventilated cavitation.

关键词： natural cavitation ventilated cavitation shapecharacters water tunnel experiment projectile experiment

Modeling and Simulation of Supercavity with Inertial Force in the Horizontal Curvilinear Motion

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China Ocean Engineering 2014年第1期28卷 31-42页

作者：邹望于开平 R.E.A.Arndt 张广 School of Astronautics Harbin Institute of Technology Saint Anthony Falls Laboratory University of Minnesota

To make a curvilinear motion in the horizontal plane is one of the most contents for realizing the maneuverability of the supercavitating vehicle. It is significant to achieve the controllability and maneuverability of the vehicle in three dimensions both theoretically and practically on research. Models of angle of attack, gravity and inertial force effects on the supercavity in the horizontal curvilinear motion are established, respectively. The supercavity is simulated based on these models in combination with Logvinovich model and the unsteady gas-leakage rate model at the given ventilation rate, and the effect of the inertial force on it is analyzed numerically. Results show that the maximum deviation of the center line of the cross section of supercavity towards the outward normal direction of its trajectory increases as the cavitation number or curvature radius decrease and always occur in the tail because of the increase of inertial effects along the axis of supercavity from the cavitator when other models and flow parameters are constant for the given trajectory curvature. For the variable curvature, the supercavity sheds due to its instability caused by the time-varying angle of attack. The deviation increases along the length of supercavity if the curvature remains the same sign.

关键词： supercavity inertial force curvilinear motion curvature rodius

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多族群粒子群优化算法飞行器结构模型修正

振动与冲击 2013年第17期32卷 79-83,99页

作者：于开平刘荣贺哈尔滨工业大学航天工程与力学系哈尔滨150001

针对粒子群优化(PSO)算法极易陷入局部最优的缺陷,提出了一种多族群粒子群优化算法(MRPSO),该算法具有较强的全局搜索能力,能极大地降低搜索陷入局部最优的概率。并将该算法引入到有限元模型修正中,对某型号飞行器结构进行了优化修正,... 详细信息

针对粒子群优化(PSO)算法极易陷入局部最优的缺陷,提出了一种多族群粒子群优化算法(MRPSO),该算法具有较强的全局搜索能力,能极大地降低搜索陷入局部最优的概率。并将该算法引入到有限元模型修正中,对某型号飞行器结构进行了优化修正,修正后结构的固有频率都有了非常明显的改善,证实了MRPSO算法的有效性及工程应用价值。

关键词：模型修正优化多族群粒子群优化算法导弹结构

基于基础激励试验数据的卫星结构有限元模型修正

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宇航学报 2013年第9期34卷 1187-1194页

作者：刘荣贺于开平哈尔滨工业大学航天工程与力学系哈尔滨150001 北京机械设备研究所北京100854

结合航天工程中卫星结构普遍进行的振动台振动试验,提出了一种基于基础激励试验数据的设计参数型有限元模型修正方法,用数值差分代替灵敏度分析,提高了计算效率,整个修正步骤更加适合工程应用。然后利用该算法对某型号卫星整星结构进行... 详细信息

结合航天工程中卫星结构普遍进行的振动台振动试验,提出了一种基于基础激励试验数据的设计参数型有限元模型修正方法,用数值差分代替灵敏度分析,提高了计算效率,整个修正步骤更加适合工程应用。然后利用该算法对某型号卫星整星结构进行了修正,并提出了两步修正策略。修正后,有限元模型的加速度响应计算结果更加接近于试验测量值,均方根误差也比修正前有了不同程度的降低,证实了该算法对卫星结构的修正是行之有效的。

关键词：有限元模型修正基础激励响应数据卫星结构

考虑热对材料参数影响的FGM梁热后屈曲特性研究

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工程力学 2019年第4期36卷 52-61页

作者：何昊南于开平哈尔滨工业大学航天科学与力学系哈尔滨150001

功能梯度梁热后屈曲特性研究对于推进功能梯度材料在航天器热防护设计中的应用有着重要意义。基于经典梁的几何非线性理论和物理中面的概念,建立了热载荷作用下功能梯度梁的运动微分方程,通过化简得到一个仅关于挠度的四阶微分-积分方程... 详细信息

功能梯度梁热后屈曲特性研究对于推进功能梯度材料在航天器热防护设计中的应用有着重要意义。基于经典梁的几何非线性理论和物理中面的概念,建立了热载荷作用下功能梯度梁的运动微分方程,通过化简得到一个仅关于挠度的四阶微分-积分方程,并与固支边界条件构成特征值问题,分析研究了功能梯度梁的热后屈曲及在此基础上的振动问题。首先证明了通过哈密顿原理推导的运动方程是轴线可伸长理论的近似形式。接着考虑热对材料物性参数的影响,并对梁的长细比、功能梯度指数和温度比作了详细分析,研究了这些参数对热后屈曲路径和后屈曲振动的影响规律。结果表明:只有在长细比较大时才可以不考虑温度对材料物性参数的影响,否则误差较大;长细比、功能梯度指数和温度比的增大会增大无量纲热屈曲载荷,同时使屈曲路径和频率-载荷曲线向热载荷增大的方向移动。

关键词：功能梯度梁热后屈曲振动解析解基频

基于前向神经网络的非线性时变系统辨识改进EKF算法

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振动与冲击 2010年第8期29卷 5-8页

作者：于开平牟晓明哈尔滨工业大学航天学院哈尔滨150001 哈尔滨工业大学电气工程及自动化学院哈尔滨150001

为了克服传统扩展卡尔曼滤波算法进行参数估计时可能产生的新数据失效问题,提出了一种改进的扩展卡尔曼滤波(EKF)步骤,然后将改进步骤做为人工神经网络的学习算法用于基于前向神经网络的非线性时变系统辨识。与传统的扩展卡尔曼滤波步... 详细信息

为了克服传统扩展卡尔曼滤波算法进行参数估计时可能产生的新数据失效问题,提出了一种改进的扩展卡尔曼滤波(EKF)步骤,然后将改进步骤做为人工神经网络的学习算法用于基于前向神经网络的非线性时变系统辨识。与传统的扩展卡尔曼滤波步骤相比克服了新数据的饱和现象,可以更好地反映系统时变特征。通过一个单变量一般时变非线性系统和一个三自由度非线性时变刚度结构系统算例,仿真验证了新算法在辨识精度和计算量方面的改进特性。

关键词：非线性时变系统多层前向神经网络系统辨识改进扩展卡尔曼滤波算法