气固流化床压力脉动信号的Wigner谱分析

用Wigner谱首次对气固流化床压力脉动信号进行时频二维分析,压力脉动信号的强非平稳性得到了证实.在Wigner谱平面中定义了局部频峰加权平均频率参数,从实验角度研究了流化床气速、静床高对压力脉动信号加权平均频率的影响.结果表明,它具有比传统的功率谱主频好得多的统计重复性,能更准确地反映气泡相的特性.

PRESSURE FLUCTUATIONS ANALYSIS OF GAS-SOLID FLUIDIZED BED USING THE WIGNER DISTRIBUTION

In this paper, the signal s strong non-stationary feature is demonstrated with time-frequency two-dimensional analysis by using the Wigner Distribution (WD) for pressure fluctuation signal in gas-solid fluidized beds. By a parameter defined as the Local Peak Weighted Average (LPWA) in WD space, the effect of velocity and probe height of fluidized beds on LPWA of pressure fluctuation is shown experimentally. The results indicate that the LPWA has much better reproducibility and accuracy than the major frequency of power spectral density in reflecting the properties of bubble phase.