Study on measurement and model of velocity in gas–liquid two-phase stratified flow

The calculation of velocity fields in gas–liquid stratified flow holds practical significance in various engineering disciplines, particularly in chemical engineering and energy transportation. This study employs particle image velocimetry to measure the axial and radial velocity distributions of gas and liquid phases. By integrating experimental data with theoretical modeling, a more scientifically rigorous and physically consistent equation for the velocity field of gas–liquid stratified flow is developed. The results show that there are two different regions in the gas phase, which show different velocity distributions. Comparison between PIV-measured velocity distributions and model predictions reveals a maximum mean absolute deviation of 2.1% and a maximum root mean square error of 2.8%. This suggests that the model achieves considerable accuracy in determining the velocity field.