黎开管中燃烧振荡现象的实验研究发现,在不稳定发生的极限工况附近可能存在幅值周期性变化的振荡现象,也即拍振,其拍频可低于1 Hz.本文比较了铁丝网和穿孔陶瓷两种稳焰体对拍振发生的影响;通过时频分析揭示了拍振的声压脉动的主频随时间周期性变化的特征.采用基于数字信号处理器的控制系统,研究了对极限环和拍振的主动控制效果,实验结果表明,黎开管系统中导致拍振的非线性可能使得采用常规主动控制方法难以取得满意的控制效果.
In experimental investigation of combustion instabilities in a Rijke tube,a pattern of oscillations with periodic amplitude variation can be observed near the limit conditions of instability.They are called beat in this paper and their beat frequencies can be as low as 1 Hz.The flame holder effect on the occurrence of beats has been studied with two types of flame holders,which are made of steel gauze and perforated ceramics,respectively.Joint time-frequency analysis results show that the fundamental frequency of pressure fluctuations during a beat can be varied.Active control experiments of limit cycles and beats have been conducted with a digital signal processor (DSP) based control system.The results reveal that the nonlinearity which leads to beat in the Rijke tube system can cause failure of conventional active control techniques.
参考文献
| [1] | Noiray N;Durox D;Schuller T;Candel S .A unified framework for nonlinear combustion instability analysis based on the flame describing function[J].Journal of Fluid Mechanics,2008(0):139-167. |
| [2] | Kabiraj, L.;Sujith, R.I..Nonlinear self-excited thermoacoustic oscillations: Intermittency and flame blowout[J].Journal of Fluid Mechanics,2012:376-397. |
| [3] | Tim C. Lieuwen .Experimental Investigation of Limit-Cycle Oscillations in an Unstable Gas Turbine Combustor[J].Journal of Propulsion & Power,2002(1):61-67. |
| [4] | 翁方龙,朱民,李东海.黎开管中燃烧振荡的非线性现象研究[J].工程热物理学报,2013(08):1582-1585. |
| [5] | Qian Shie;Chen Dapang .Joint time-frequency analysis[J].IEEE Signal Processing Magazine,1999(2):52-67. |
| [6] | Evesque S.;Dowling AP.;Annaswamy AM. .Self-tuning regulators for combustion oscillations[J].Proceedings of the Royal Society. Mathematical, physical and engineering sciences,2003(2035):1709-1749. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%