Abstract
The turbulence reduction by the polymer-solution at free surface is experimentally investigated The water or polymer-solution jet flew horizontally from the circular nozzle which was set beneath the free surface. The interaction between the jet and the free surface caused the small waves on the free surface. The movement of the surface was measured by the water level meter. The characteristics of the free surface with and without polymer-solution were evaluated using the measured data and visualized images. The free surface with polymersolution was more stable than that of pure water. The jet and free surface were visualized by the laser light sheet. The shear reduction by the polymer-solution were found to play the important role on the free surface turbulence.
