Optimizing lateral intakes in river bends near broad-crested weirs: a hydraulic perspective

This study numerically investigates bilateral intakes around a broad-crested weir in a 90° river bend. The influence of interior intake angle (30°, 45°, 60°, 90°) and the effects of the sill and weir on discharge distribution is analysed. Results indicate that a 30° angle provides the most uniform flow and balanced discharge (each intake receives approximately 0.31 and 0.32 of the total flow at 35 l s−1). A 90° angle produces severe flow separation, reducing interior intake efficiency to no more than 0.04. The sill substantially reduces interior intake discharge, especially at 60°, where it falls to less than one-fifth of the no-sill value. Conversely, the broad-crested weir increases diverted discharge by factors of 2.9–14.4, depending on angle. This study demonstrates feasible water diversion from the inner bend and offers guidance for optimizing similar hydraulic systems.