Fluid Vibration Induced by High Shear Rate Flow in a T Junction

Abstract

For laminar flow in the side branch of a Tjunction, periodic fluid vibrations occur with the Strouhal number independent of characteristic flow conditions. As the mechanics is unknown, an experiment was performed to establish the underlying cause in highshearrate flow. The fluid vibration appears along both the shearing separation layer and the boundary between two vortices immediately downstream of the side branch, where the shear rates are several orders larger than those further downstream. This vibration is caused by flow instability induced in two types of highshearrate flow confirming that is a universal phenomenon associated with the geometry of the Tjunction.