Wetted wall fraction of gas-liquid stratified co-current two-phase flow in a horizontal pipe with low liquid loading

An investigation of the wetted wall fraction of gas-liquid stratified co-current two-phase flow in a horizontal pipe with low liquid loading was carried-out experimentally. The pipe length and the inner pipe diameter were 10 m and 26 mm respectively. The tested fluids were air and water. The superficial water (JL) and air (JG) velocities ranged from (0.02–0.075) m/s and (4–16) m/s respectively. In the experiments, the circumferential liquid film thickness was measured by using developed parallel wire sensor, and verified by the analyzed image of the axial view of the visual observations. At the same time, the pressure gradient and liquid hold-up data were taken in order to determine the interfacial shear stress between gas and liquid. The results indicate that (1) JL and JG significantly affect the interfacial shape of gas and liquid stratified flow in a horizontal pipe, whereas starting from JG = 8 m/s the interfacial shape changes from flat-shaped to concave-shaped interfaces, (2) a new correlation to predict the wetted wall fraction (WWF) of gas-liquid stratified flow in a horizontal pipe was also proposed, and yielded the mean absolute prediction error (MAPE) of 20.6% in comparison with the obtained experimental data from the present study and the available data in open literatures.