A time-frequency signal processing method for two-phase flow through a horizontal Venturi based on adaptive optimal-kernel (AOK) was presented in this paper.First

the collected dynamic differential pressure signal of gas-liquid two-phase flow was preprocessed

and then the AOK theory was used to analyze the dynamic differential pressure signal.The mechanism of two-phase flow was discussed through the time-frequency spectrum.On the condition of steady water flow rate

with the increasing of gas flow rate

the flow pattern changes from bubbly flow to slug flow

then to plug flow

meanwhile

the energy distribution of signal fluctuations show significant change that energy transfer from 15-35 Hz band to 0-8 Hz band;moreover

when the flow pattern is slug flow

there are two wave peaks showed in the time-frequency spectrum.Finally

a number of characteristic variables were defined by using the time-frequency spectrum and the ridge of AOK.When the characteristic variables were visually analyzed

the relationship between different combination of characteristic variables and flow patterns would be gotten.The results show that

this method can explain the law of flow in different flow patterns.And characteristic variables

defined by this method

can get a clear description of the flow information.This method provides a new way for the flow pattern identification

and the percentage of correct prediction is up to 91.11%.