Hydrodynamic structure of the flow around a stationary gas bubble in an annular channel

Abstract

Abstract Characteristics of the slug gas liquid flow in an annular channel were studied experimentally. The channel had the diameters of outer and inner tubes of 32 and 10 mm. The liquid flow was downward. The stationary bubble (gas slug) was produced by injecting air through a capillary tube. Wall shear stress measurements were performed by electrodiffusional technique. The measured circumferential distributions of wall shear stress demonstrated a strong non-uniformity across the channel. The highest liquid velocity was in the region of bridge streamining the bubble. The highest values of wall shear stress fluctuations are in the transition region between gas bubble and liquid bridge.