Two-Phase Flow in an Annular Channel With an Obstacle

Abstract

Experimental study of gas-liquid two-phase flow in an annular channel is performed. The channel consisted of two coaxial tubes with the diameters of 42 and 20 mm. An obstacle covering a quarter of the channel section was placed in the channel to produce a strong three-dimensional disturbance of the flow. Gas-liquid flow was produced by injecting air bubbles at the channel entrance through a special mixer. Measurements of local wall shear stress are performed using an electrochemical technique. Measurements of time-averaged and fluctuational wall shear stress are performed at various points relative to the obstacle, this allowed to study the field of the hydrodynamic parameters of the flow. Local void fraction is measured using a conductivity probe which traversed across the channel. The distribution of local void fraction in the region downstream the obstacle is obtained. Increased values of local void fraction in the region close to the obstacle are detected. The experimental data obtained can be used for validation of existing and developing computer codes accounting for a 3-D structure of two-phase flows.