用热膜测速技术以高于对应最小湍流时间尺度的分辨率精细测量了环流反应器内气液二相流速度的时间序列信号,对气液二相流速度信号中自动识别泡状流结构进行了研究。用子波分析方法,将热膜测速仪输出的气液二相流混合速度信号在时域空间和频域空间同时进行时频双局部化多尺度分解,研究了气液二相流中液相流和泡状流结构的分尺度时域特征和分尺度能谱等统计特征,利用子波能谱分析的能量最大准则,提出了一种用子波变换自动识别气液二相流中泡状流结构的新方法。
The velocity time sequence of gas-liquid two-phase flow at different vertical locations in a reflux reactor was finely measured by constant-temperature hot-film anemometer with resolution higher than the frequency that corresponds to Kolmogorov dissipative scale. The automatic discrimination of bubbly flow structure in gas-liquid two-phase flow was studied. The wavelet analysis was used to perform the time-frequency double local decomposition in time space and frequency space for the hot-film anemometer output mixed signal of the gas-liquid two-phase flow. The multi-scale character of bubbly flow structure in time space, the energy evolution across scales and other statistic characters were studied. With the use of energy maxima criterion, a new method of automatic discriminating the bubbly flow structure in gas-liquid two-phase flow was developed.