Visualization of Velocity Profile and Measurement of Wall Shear Stress in Branched Square Tube Using Laser-Induced Fluorescence Method

Abstract

Visualization and quantitative measurements of the velocity field of a laminar water flow through a branch tube of square cross section was made using a laser-induced fluorescence or phosphorescence (LIF or LIP) method. Velocity profiles in two directions across the tube were visualized in a total of 23 different cross sections located at the upstream and downstream of the branch and along the flow direction. The wall shear stress was obtained from these visualized velocity profiles and the map of the wall shear stress over the whole flow field was obtained.