Experimental and theoretical study of two-phase flow in wide microchannels

•The pressure drop in two-phase flow have been experimentally and theoretically investigated.•The characteristic liquid thickness have been calculated for stratified flow regime.•Regular waves on a liquid film in a microchannel have been experimentally detected.•Wavelengths and phase velocities of waves are obtained by conducting a linear stability analysis.•Plane stratified flow model is in good agreement with experimental results for wave characteristics. Experimental and theoretical studies of the two-phase flow regimes in a wide microchannel with the height of 164 μm were performed. The ranges of parameters of the formation of the main flow regimes are determined: jet, bubble, churn, stratified, and annular. The pressure drop in single-phase and two-phase flows was measured. Using a flat flow model, we performed a theoretical study of the pressure drop and compared it with experimental data. Regular waves were experimentally detected in film flow regimes. The formation of waves on a liquid film was investigated, and characteristic wavelengths were measured. As for the theory, the study of linear stability of the stratified two-phase flow regime in a wide microchannel was performed. The comparison of numerical and experimental results indicated the validity of the proposed approach for modeling waves in film regime in wide microchannels.