The study of identifying flow patterns of air-water two-phase flows in horizontal pipes based on the detected signals

Accurately identifying flow patterns severely influence on choosing proper formulas to calculate in design, choice about equipment types and normally running and installing the piping etc. The methods on identifying flow patterns mainly include direct ways and indirect ways. The direct ones ascertain flow patterns according to the flow forms of the two-phase flow, and the indirect ones identify flow patterns according to the signal that can reflect the flow characteristics of two-phase flow. In the study the differentiate rule on flow patterns transition is gained combining average value analysis, mean square root analysis, time domain analysis, PDF and FFT of holdup with fractal dimension of pressure fluctuation.