Author(s): M. A. Omidbeigi; S. A. Ayyoubzadeh; A. Safarzadeh
Linked Author(s):
Keywords: Lateral Intake; Spiral Motion; Numerical Simulation; Turbulence; Bed Shear Stress
Abstract: In this study, an experimental investigation of the flow characteristics in a 90°, sharp edged, rectangular open channel junction, with a main channel of 1m width and 1:6 aspect ratio and a lateral intake channel of 0.4m width is presented. 3D velocity measurements are conducted using an Acoustic Doppler Velocimeter at study region. The average velocity magnitudes, bed shear stresses and turbulence parameters were determined using measured time series of velocity components. A 3D CFD model that solves RANS equations closed with the standard k-ε, k-ε and RSM turbulence models in conjunction with physical ones were also used in order to get a deeper insight into the physical nature of complex flow at lateral intake. The measured flow data are then used to calculate the distribution of bed shear stresses with the inclusion of correction factor for the effect of local spiral motions. It is found that for lateral intake flow, the prediction of RSM model has the best agreement with measurements and the accuracy of the k-ε model in simulating observed velocity data is better than the standard k-ε model. The comparative results indicated that the distributions of modified bed shear stresses are satisfactorily reproduced by experimental calculation.
Year: 2009