Abstract
In intake facilities of a hydroelectric power station, intake vortices cause an air-hammer in an intake tunnel and a cavitation at turbine blades of a water turbine generator by air-entrainments. In order to understand hydraulic characteristics of intake vortices in a vertical intake facility, flow fields in the basic model of a vertical intake facility that combined a rectangular linear channel and a vertical pipe have been measured using a Particle Tracking Velocimetry(PTV). In the horizontal plane near the free surface around the end of the intake channel, the results show that vortices generated at the both sidewalls move to the occurrence region of intake vortices. And in the vertical plane at the center of the intake channel, the results show that local vortices unrelated to the approach flows occur at the outer edge of the vertical pipe.
