Consideration of Velocity Gradient Distribution of Rigid Sphere in Wake Region

Abstract

The field of two-phase flows has been interested in the interfacial flow of a dispersed phase such as bubble and water drop. The interface is contaminated by the contaminant included in surrounding liquid. The contaminant is carried backward by the interfacial flow. The contaminant accumulates in a rear region of the dispersed phase. The interface in a rear region becomes like the solid wall by the accumulated contaminant. Previous studies could measure the interfacial flow of a spherical water drop in this condition. The interfacial velocities in a rear region were 0. This result is the same as the solid wall. However, the value of velocity gradient in a rear region was larger than theoretical value of the rigid sphere which is Stokes flow. The difference of this value has possibility of the influence by the contamination and the wake region behind the water drop. This study aims to measure the velocity gradient distribution around a rigid sphere. Our experimental results show that the velocity gradient distribution in the wake region is lager value than the theoretical value.