Many publications propose a flow-pattern identification method for two-phase flow in a microchannel,3–83. J. Shao et al., Exp. Therm. Fluid Sci. 85, 240 (2017).4. J. López et al., Exp. Therm. Fluid Sci. 76, 126 (2016).5. G. Alcan et al., Flow Meas. Instrum. 51, 55 (2016). https://doi.org/10.1016/j.flowmeasinst.2016.08.0056. P. Zhang and H. W. Jia, Chem. Eng. J. 306, 978 (2016). https://doi.org/10.1016/j.cej.2016.08.0347. M. H. Maqbool, B. Palm, and R. Khodabandeh, Exp. Therm. Fluid Sci. 46, 120 (2013). https://doi.org/10.1016/j.expthermflusci.2012.12.0028. Z. Yang et al., Appl. Therm. Eng 120, 654 (2017). and visual observation has proved the preferred method for identifying gas–liquid two-phase flow patterns.