Numerical Evaluation of Submerged Vane Application in Sedimentation and Erosion Potential of Flow in 90° Open-Channel Junctions

Open-channel junctions have a broad application in hydraulic engineering. Formations of a low pressure zone with recirculating flow at downstream edge of the junction (with high sedimentation potential) accompanied by a high-velocity zone (with high erosion potential) located at the opposite wall of junction are the most characteristic features of flow in junctions. Literature addressed a lot of numerical studies on evaluation of flow pattern in open-channel junctions and elimination of aforementioned problems using geometrical modifications, application of lateral channel separating wall, implementation of oblique angles of lateral channel, and so on. Using submerged vane to reduce amount of erosion as well as sedimentation potential, has comprehensively been assessed in the present paper. First, the numerical model was validated by previous studies. Second, a large number of numerical models have been performed to evaluate the effects of mentioned solution in open-channel junctions. Moreover, optimal ranges of different submerged vane’s parameters have been introduced. The results show a comprehensive reduction in sedimentation and erosion potential of open-channel junctions. For example, 89% reduction in length of separation zone has been detected in one of the proposed solution. In addition, the best performance of these vanes was observed in discharge ratio of 0.25. Moreover, applications of vane with height of more than 0.5h (h represents water depth) and/or angle of more than 40° are not suggested.