Detecting gas–liquid two-phase flow pattern determinism from experimental signals with missing ordinal patterns

To address the issue of whether there exists determinism in a two-phase flow system, we first conduct a gas–liquid two-phase flow experiment to collect the flow pattern fluctuation signals. Then, we investigate the determinism in the dynamics of different gas–liquid flow patterns by calculating the number of missing ordinal patterns associated with the partitioning of the phase space. In addition, we use the recently proposed stretched exponential model to reveal the flow pattern transition behavior. With the joint distribution of two fitted parameters, which are the decay rate of the missing ordinal patterns and the stretching exponent, we systematically analyze the flow pattern evolutional dynamics associated with the flow deterministic characteristics. This research provides a new understanding of the two-phase flow pattern evolutional dynamics, and broader applications in more complex fluid systems are suggested.