The flow structure dynamics of gas-liquid two-phase was analyzed with a novel approach

multi-scale complexity entropy causality plane (MS-CECP)

derived from the information entropy theory. Firstly

the method was used to investigate typical chaotic time series and then to process the conductance fluctuating signals of three typical gas-liquid flow patterns

i.e.

bubble flow

slug flow

and churn flow. The single scale CECP could discriminate the different flow patterns linearly. Furthermore

MS-CECP could describe the continuous information loss of flow structures with the increase of scale

which reflected flow structure stability and complexity of the gas-liquid two-phase flow system. The proposed approach (MS-CECP) was proven to be a useful analysis tool for understanding the nonlinear dynamics of flow structure in two-phase flows.