| It is common in different open channel flow systems, such as cooling tower basins, irrigation systems, and other water distribution systems, for two flows of equal magnitude to collide and then turn 90-degrees into a downstream channel. When this occurs two separation zones are formed in the downstream channel. Presently there is no method to predict the maximum width of these separation zones.; This study conducted a physical model study to study the separation zones in this hydraulic phenomenon. The physical model study was used to validate a numerical model and an analytical method of the opposing flow condition. There was excellent agreement between the numerical model, analytical method (approach 4B), and the physical model. The numerical model was then used to study test conditions outside of the scope of the physical model study. The results for these test conditions were used to develop a series of curves of the ratio of upper channel width to lower channel width, L/W. These curves and the validated analytical method approach can be used to predict the maximum width of the separation zone. The curves require the ratio of the upper channel width to lower channel width, L/W and upstream Froude number, F1, while the validated analytical method approach requires the L/W ratio, the upstream Froude number, F1, and the flowrate in one upper channel. |
