The effect of the liquid viscosity on the liquid film thickness and wave frequency of the gas-liquid stratified co-current flow in horizontal pipes

The aim of the present study is to investigate the effect of the liquid viscosity on the liquid film thickness and the wave frequency of gas-liquid stratified co-current flow in a horizontal pipe. The inner diameter of the pipe is 26 mm. The superficial liquid velocity (JL) increased from 0.02 m/s to 0.1 m/s, while the gas superficial velocity (JG) increased from 4 m/s to 16 m/s. High speed video camera is used to take high quality visual data which is then processed using image processing techniques. From the results of this study, it is concluded that an increase in JG causes a decrease in the liquid film thickness, while an increase in liquid viscosity causes an increase in the liquid film thickness. From the entire JL range in this experiment, at JG > 8 m/s, the wave frequency tends to increase with increasing JG, while the wave frequency decrease with increasing liquid viscosity. In addition, the Reynold number ratio of gas and liquid and the Martinelli parameters affect the present proposed correlation to predict the frequency wave. The present proposed correlation to predict the frequency of the wave shows a satisfactory performance with the Mean Absolute Percentage Error values 27.1. © 2024 AIP Publishing LLC.