Slug flow development study in a horizontal pipe using particle image velocimetry

Abstract

The development of slug flow along a horizontal pipe was quantitatively investigated through particle image velocimetry. Quantitative information is essential to understand the hydraulic behavior of the slug flow and is a reference for numerical simulations. The flow in the horizontal pipe of 11.5 m length and 0.051 m diameter was maintained in a fully turbulent condition with 0.41 m/s gas superficial velocity and 0.50 m/s liquid superficial velocity. PIV measurement was carried out at three locations along the pipe, and a sophisticated ensemble averaging technique was applied to obtain the statistical flow properties. Morphological analysis revealed the unsteadiness of Taylor bubble and variation of bubble population in the slug region. From the velocity information, the similarity of velocity fields in the slug body and tail is found. In addition, the occurrence of local maximum velocity and an increase of the mixing eddy length in the slug nose were observed. Moreover, a modified 1D mixture model to predict the slug translational velocity was proposed based on the local maximum velocity in the slug tail. We believe this study clearly shows the strength of PIV method to improve the understanding of physics in the slug flow. (C) 2020 Elsevier Ltd. All rights reserved.