Author(s): Guillaume Bon; Baba Mba-Assoumou; Ludovic Chatellier; Laurent David

Linked Author(s): Laurent David

Keywords: Hydropower plants; Ecological continuity infrastructures; Angled bar rack; Natural clogging; Head losses

Abstract: Hydroelectric power plants (HPPs) are constantly being upgraded to enhance their performance in terms of both river continuity and energy production. To meet these requirements, specific infrastructures are implemented. In particular, angled narrow bar spacing racks with lateral downstream bypasses can be installed at the water intake of HPPs to improve the downstream migration of fish. However, these systems may experience significant head losses when natural debris accumulate on the racks. An experimental study was conducted in a free-surface channel flow using an angled bar rack with artificial clogging. The head loss for each configuration, including both homogeneous and partial surface clogging, was measured, demonstrating the significant impact of clogging on hydraulic losses. The head loss was found to increase with the obstruction ratio and the clogged surface ratio. The results were compared with an existing formula for clogged incl ined bar racks, and an adaptation is proposed. This work contributes to a better anticipation and quantification of clogging effects during operations.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.190

Year: 2026