抄録
Experiments were performed to determine friction factors for turbulent flow in various wavy sinusoidal channels. The Reynolds number, based on the duct volumetric equivalent diameter, ranged from 300 to 40000. Flow visualization, using the dye and particle track techniques, revealed that the periodic change in the size of the recirculation zone was accompanied with the sweep and burst of large scale vortices. For the friction factor, the correlation formula f=CRe-n was used, in which the exponent n and coefficient C were related as a function of the channel geometry.
