Flow field behind a fixed bluff body in a vertical pipe simulating a wake of a Taylor bubble

Abstract

The hydrodynamic structure of the wake of an axisymmetric bluff body that simulates the shape of a moving elongated (Taylor) bubble in a vertical pipe was studied using Particle Image Velocimetry in laminar and turbulent background flows. The distribution of the mean axial and radial velocity components in the wake, as well as the spatial variation of the normal and shear stresses are presented and compared with the corresponding quantities in the wake of the gas bubble. The accumulated results enable estimates of the spatial variation of turbulent energy production term in the undeveloped separated flow in the wake of the bluff body.