Author(s): Mehmet Ardiclioğlu; Donald W. Knight
Linked Author(s): Donald W. Knight
Keywords: Open channel flow; Velocity; Boundary Shear Stress; SKM Method
Abstract: The velocity and boundary shear stress distributions in open channel flows are important for prediction of discharge, sediment transport, bank protection and other river engineering problems. The Shiono and Knight Method (SKM) is based on a depth-averaged form of streamwise Reynolds Averaged Navier-Stokes equations and a simple two dimensional tool capable of predicting the depth-averaged velocity and boundary shear stress distributions accurately. The SKM is governed by three calibration coefficients f, λ, and Γ, concerned with local bed friction, lateral shear, and secondary flow respectively. This paper investigates roughness effect on secondary flow parameter Γ in rectangular channels flow. For this purposes three different surfaces were used (smooth, k=1 and 0. 7 cm) and six different flow conditions obtained for each surfaces. The friction factors used were obtained by applying Darcy-Weisbach equation, constant ‘standard’ values for λ were imposed in all the panels, λ=0. 07 and Γ values were adjusted to match the experimental depth-averaged velocity data. Panel numbers were investigated for different roughness and one panel solutions gave good approximations with measured data. Using constant λ=0. 07 value and measured f values, secondary flow term Γ were investigated for different flow and roughness conditions and third degree polynomial equation was obtained and given in Equation 5.
Year: 2007