Author(s): Janek Laanearu; Kaspar Alles
Linked Author(s): Janek Laanearu
Keywords: No Keywords
Abstract: It is shown that the low-head dam downstream-part energy dissipation intensity depends on the underwater vortical pattern, which extends toward obstruction located downstream of the weir in the lower course of river. The specific energy function and momentum equation of the non-rectangular cross-section channels can be used to perform a hydraulic analysis for both the hydraulic jump and rapids-type flow situations (Laanearu, 2024). The quadratic-type channel hydraulic framework is used for this purpose, i.e. the low-head dam downstream flow characteristics are explained for pre- and post-reconstructed situations. It is shown that the underwater vortical pattern of pre-rebuilt weir is considerably changed as it is compared to the post-rebuilt situation. The rapidly varying flow at weir and rapids, depending on extreme river flow events, are discussed to explain the hydraulic modelling challenges due to climate changes and future river-basin restoration studies.
Year: 2026