113 Velocity Field Measurements in a Near-Wall Flow of Dilute Polymer Solution
Details
The purpose of this study is to clarify the velocity profiles of dilute polymer solution near the wall surface by using an evanescent light source. Evanescent light emerges by total reflection of an incident laser and illuminates only particles that are very close to the wall surface. By changing the incident angle of the laser, the depth of the illuminated area of evanescent light can be changed. Test fluids were water and polyethylene-oxide (Peo15) solutions with 5 ppm. Fluorescent particles with the diameter of 100nm were dispersed in test fluids are used as tracer particles. The streamwise velocity profile in the direction of depth is measured with PTV system by changing the depth of the illuminated area. It was clarified that the velocity profiles of dilute polymer solution decreases significantly comparing that of water very close to the wall surface. It can be considered that the adsorbed polymer layers may be partially responsible for the decrease in velocity of polymer solution.
