高温流化床瞬态颗粒浓度信号的Wigner分析

Local Voidage Fluctuation Analysis of Gas-Solid Fluidized Bed at Elevated Temperature Using the Wigner Distribution

应用 Wigner谱对高温气固流化床中颗粒相浓度脉动信号进行时频二维分析 ,证实了脉动信号的强非平稳性。与传统的功率谱密度分析不同的是 ,得到了在同一时刻可以只出现一个较强的局部频率峰值 ,也可以出现一个与以上强度可比的局部频率峰值。研究还发现 ,宏观相似的瞬时时域颗粒浓度信号 ,通过 Wigner谱分析可以清楚地从频域上揭示其微观存在的差异。

The signal's strong non-stationary feature is demonstrated with time-frequency two-dimensional analysis by using the Wigner Distribution (WD) for the local voidage fluctuation signal in a gas-solid fluidized bed at elevated temperatures. As compared with the power-spectral density, the WD shows that there is not only a major local frequency but also more than one major local frequency may exist at the same time for the signals. Also, it clearly reflected the different microstructures of the signals even with the macrostructure similarities of the signals.