2024 Volume 80 Issue 16 Article ID: 23-16163
In this study, correlation between the surface instantaneous velocity distribution characteristics and internal structure of turbulent flow in a smooth open channel were investigated using flow velocity measurements and flow visualization methods. As a result, it was clarified that a parallel cycloidal flow was formed in the instantaneous flow velocity distribution even when the bottom wall surface was smooth. Simultaneous visualization of instantaneous water surface velocity and internal flow regime revealed that the longitudinal vortex structure directly contributed to the velocity distribution on the water surface. Furthermore, as a result of examining the correction factor of the water surface float from the instantaneous flow velocity distribution, the ratio of the average flow velocity in the relatively high-speed region corresponding to the parallel spiral flow to the cross-sectional average flow velocity was 0.77. The correction factor of the surface float is 0.85, which is smaller than the value of this study, about 0.08, but it was found to be in line with the results of previous investigations.
