VELOCITY FIELD MEASUREMENTS IN A NEAR-WALL FLOW OF DRAG REDUCING SOLUTION IN MICROCHANNEL

摘要

The velocity profile of a dilute polymer solution and a surfactant solution near the wall surface in a microchannel was clarified using evanescent wave illumination and a particle tracking velocimetry system. Fluorescent particles with a diameter of 100 nm were used as tracer particles. The test fluids were polyethylene-oxide (Peo15) solution at 5 ppm, oleyl-bihydroxyethyl methyl ammonium chloride (Ethoquad O/12) solution at 200 ppm and distilled water. The results obtained for the velocity profiles for distilled water and surfactant solution were found to agree well with the two-dimensional Poiseuille velocity profile. On the other hand, the velocity profile of the dilute polymer solution decreases significantly compared with that of water within 200 nm of the wall surface. These data provide the first velocity profile measurements of a dilute polymer solution and a surfactant solution in the near-wall region.