A novel mechanistic model of low liquid loading gas-liquid stratified flow in horizontal pipes considering the effect of interfacial waves

Low liquid loading gas-liquid stratified flow appears most frequently in wet gas gathering and transportation pipelines. This study devised a novel mechanistic model of low liquid loading gas-liquid stratified flow in horizontal pipes considering the effect of interfacial waves. The minimum energy principle was introduced to determine the interfacial configuration and characteristic wavelength. The gas-liquid interface shape was mainly influenced by superficial gas velocity, superficial liquid velocity, pipe diameter, and liquid hold-up, while the wave properties was derived from the interface Kelvin-Helmholtz instability affected by gravity, Bernoulli effect, capillary force, and viscous dissipation together. Based on governing physical parameters, a new correlation for interfacial friction factor was proposed by considering the wave properties. An air-water two-phase flow experiment was conducted to observe the low liquid loading gas-liquid stratified flow within a 40mm diameter horizontal pipe and obtain the liquid hold-up and pressure gradient data. Compared with the existing four models, the proposed model was in better agreement with some experimental data available in literatures and current study, and the average errors in predicting pressure gradient and liquid hold-up are 19.66% and 9.58%, respectively. The present study was expected to provide a new approach for predicting gas-liquid stratified wavy flow.