脉动理论

By means of dimensionless analysis an experimental correlation for predicting stability of the system is obtained and the stability threshold diagrams have been found.

根据试验和理论分析结果，提出了消除系统的不稳定，提高系统稳定性及防止脉动发生的措施。

In this paper, the FIR low-pass digital filtering method is first introduced for reducing the effects of noise signals in the experiment of velocity measurement of high-temperature flue gas flowing in pipe. The experimental results indicated that, only one peak presents in the cross-correlation graph, which is in good agreement with theoretical analysis result. Secondly, the temperature and pressure pulse signals of the high-temperature flue gas, obtained by thermocouple and pressure sensor, are introduced to explain the applicability of sensor characteristics.

本文介绍在测量管内流动的高温烟气流速的实验中采用FIR低通数字滤波器滤波方法可以排除干扰信号的影响的研究，实验结果证明，经过滤波处理后的信号互相关函数的图形不会出现大小相当的多个峰值，符合理论分析的结果；其次，本文还介绍了用热电偶和压力传感器采集的烟气温度和压力脉动信号，分析了传感器特性对相关测速的适应性。

In this paper, the fundamental principle of random process theorem is applied to the analyses of fluctuating pressure amplitude and frequency cha- racteristics of the overflow tower.

本文应用随机过程理论的基本原理，对泄水塔泄流的脉动压力的幅值特性及频率特性进行了分析。

In mathematics, it can be boiled down to two equivalent forms of a kind of classical solutions to the general Navier-Stokes Equation of velocity fluctuations.

从数学而言，这一框架的理论基础可归结为描述不可压缩脉动场的Navier-Stokes方程的两个等价形式。

According to the studied results at present, the studied objects are mainly thin plate and beam about sound radiation mode, a method computed sound radiation mode of complex structure is presented in this dissertation, according to the results of the previous two chapter, a theoretical method to solve acoustical radiation mode and acoustical radiation efficiency of complex structure by boundary element method and acoustical radiation theory is posed, the acoustical radiation power is expressed as a Hermitian quadratic form, while the radiation modes is determined by general eigenvalue decomposing, and then the radiation efficiency is computed via the orthodoxy of radiation modes with regard to impedance matrix and average velocity matrix; lastly, the validity of the method is proved by pulsating sphere and radiating cube with analytical results. According to results of the form three chapter, the structure sound radiation sensitivity is studied in detail, the sound radiation power of structure can be expressed as positive Hermitian quadratic form, the sound radiation sensitivity can be expressed as two parts by partial differential with respect to design variable, which are sensitivity of boundary velocity and impedance matrix, combined with the theory of FEM and BEM, the structure sound radiation can be translated to the analysis of structure dynamic sensitivity and impedance matrix sensitivity. The theory posted in this dissertation is tested by the FEM software ANSYS and the software AAS programmed by author.

在前几章的基础上，通过结构声辐射的模态理论对结构的声辐射的机理进行了深入地探讨，针对目前声辐射模态的研究对象主要是简单的板和梁类结构，提出了一种计算复杂结构声辐射模态的方法，利用前两章研究所得的结论，将边界元方法与广义特征值的理论结合起来研究了复杂结构的声辐射模态与声辐射效率，先将结构的声辐射功率表示为一个正定的厄米特二(来源：ABb7C论文0909网www.abclunwen.com)次型，运用广义特征值分解求解了复杂结构的声辐射模态，然后利用声辐射模态关于阻抗矩阵与均方速度耦合矩阵的正交性，求解了复杂结构的声辐射效率，最后用具有解析解的脉动球与辐射立方体验证了该方法的有效性。

In accordance with the situation that the damping was the non-classical damping,the structure was asymmetric,and random wind spectrum was irrational fraction wind spectrum,the equations obtained were decoupled with the complex mode theory.

建立运动方程，用第一振型将主体结构展开，针对非经典阻尼和非对称结构以及脉动风谱为非有理分式风谱的情况，运用复模态理论将所得方程进行解耦，获得了以第一振型表示的结构随机风振响应的解析解。

The paper calculates and analyses an coupling oscillating mode trait of chute -flow-dam body and the dynamic stability of the chute of overfall concrete face rockfill dam by using ANSYS finite element software and the theory of fluid-solid coupling.

采用ANSYS有限元软件和流—固耦合理论[1，2]，计算、分析了溢流混凝土面板堆石坝的泄槽—水流—坝体的耦合振动模态特性和泄槽动力稳定性，同时应用随机振动理论对脉动压力作用下的泄槽及地基的动力响应作出了定量估算，与原来的双渐方法的结果进行了比较，验证了计算结果的合理性，进而分析了坝体动弹模和堆石厚度对系统动力特性的影响。

Theoretical analysis and the tests show that the control system with the strategy can effectively suppress pressure pulsation.

理论及试验研究均表明：基于B样条神经网络的自适应有源降脉系统能有效地衰减系统的压力脉动。

The residual pulsant Reynolds stress term of coherent structures was compared quantitatively with the Reynolds stress contribution term of random fluctuation based on theoretical analysis.

基于理论上对湍流相干结构动量方程中随机脉动对相干结构贡献的雷诺应力和相干结构剩余脉动雷诺应力项的分析，对两种雷诺应力项进行了对比研究。

The data acquisition system of this system adopts configuration software MCGS (Monitor and Control Generated System), the establishment of the database , the display of real-time data and historical data , design of the interface, connection of the cartoon and the realization of different curves such as course curve of noise and temperature , course curve of pressure fluctuation and course curve of work efficiency , etc. are finished in development and design of the data acquisition system. Having made comparatively deep research on the vibration theory and combining this theory with the practical pumping station pectrum analysis to data of this pumping station is carried through and the preliminary diagnosis result is received.

本系统的数据采集系统采用组态软件MCGS，在数据采集系统的开发与设计中，完成数据库的建立，实时数据与历史数据的显示、界面的设计，动画的连接，各种曲线的实现，如噪音与温度过程曲线、压力脉动过程曲线和工作效率过程曲线等；对振动理论做了较为深入的研究，并将理论与实际泵站结合，对该泵站的数据进行频谱分析，并得到初步的诊断结果。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。