Author(s): D. H. Yoo; T. H. Lee
Linked Author(s):
Keywords: Laminar flow; Transitional laminar flow; Smooth turbulent flow; Transitional turbulent flow; Rough turbulent flow; Dimensionless numbers associated with surface tension
Abstract: The research on open channel flow was theoretically established by Chezy in the middle of 1700 while wider and more organized research was tried by Darcy (1803-1858) about 150 years ago with experimenting the water flow on the water channel of 2 meter wide and 600m long. Bazin, the Darcy's colleague or successor, conducted not only the site observation under the limited conditions, but also conducted various kinds of experimental observation by manufacturing various kinds of water channels. His experimental data have been used not only by himself but also by many researchers such as Manning, Ganguillet and Kutter, etc for making the empirical equations. Nikuradse (1933) confirmed from the experiment on the circular pipe with uniform roughness that the flows can be divided into 5 groups of laminar flow, transitional laminar flow, smooth turbulent flow, transitional turbulent flow, rough turbulent flow depending on their specific characteristics. Varwick (1945) also found that the flow in the open channel can also be classified into the 5 groups of flows in the same way as in the closed channel. In this research, we have introduced the dimensionless number Yk, Yh and Yb which considers the effects of surface tension, viscosity, specific density, slope of natural river, roughness height, depth and water surface width to the α factor of the conventional power law of friction coefficient.
Year: 2007