沸腾两相流动压力波动信号的特性

Characterization of Pressure Fluctuations in Boiling Two-phase Flow

研究了竖直管内沸腾两相流动时压力波动信号的特性,对压力波动时间序列进行了标准偏差分析、功率谱密度函数分析、分维数分析、相关维分析及Kolmogorov熵分析,考察了热流密度对压力波动的影响规律.结果表明沸腾两相流动具有非线性混沌特性,且热流密度对各特征参数有不同影响.

Experiments are carried out in the paper to study the feature of pressure fluctuating in vertical tube for boiling two-phase flow. The time series of pressure fluctuation were analyzed by means of standard deviation, power spectrum, rescaled range （R/S）, correlation dimension and Kolmogoroy entropy analyses. It is shown that heat flux had great influence on these quantitative numbers. In different velocity of flow, the fractal dimension is less than 1.5 under the various heat flux, and positive finite value of the Kolmogorov entropy was found, which means the boiling two-phase flow was nonlinear chaotic.