Experimental study on controllable pseudo-slug flow characteristics in horizontal pipe.

Pseudo-slug flow is widely encountered in the natural gas industry. More attention has been concentrated on the pseudo-slug flow existing at upward inclined pipe, but there is few researches focused on the pseudo-slug flow characteristics in horizontal pipe. In the present study, we design a controllable generator to mimic the horizontal pseudo-slug flow. The spatial and temporal distribution evolution at radial and axial directions are investigated according to the flow visualization, which includes high-speed camera and wire-mesh sensor (WMS). Notably, local structures of gas–liquid distribution divide the pseudo-slug flow into two types: long-aerated and instant-aerated. Visually, the gas penetrates into the pseudo-slug body and exists in horizontal pipe as a continuous phase. Further, the void fraction, the pseudo-slug frequency and translational velocity, and the actual gas velocity are quantitatively analyzed. The results indicate that there is a significant slip between the gas and liquid within the pseudo-slug body, which is the most critical feature for distinguishing the conventional slug flow and pseudo-slug flow. Further, this research will help to improve the knowledge system of the pseudo-slug flow and promote the establishment of theoretical models. • A controllable generator is designed to mimic the horizontal pseudo-slug flow. • The spatial and temporal evolution at radial and axial directions are investigated. • Compared with instant-aerated pseudo-slug flow, the long-aerated has longer body length and more severe fluctuation. • Unlike conventional slug, there is a significant slip in the horizontal pseudo-slug flow. [ABSTRACT FROM AUTHOR]