The Very Low Head Turbine for hydropower generation in existing hydraulic infrastructures: State of the art and future challenges

• DOI: 10.1016/j.seta.2021.101924
• Publication Date: 2022-01-05T23:59:15Z
• Authors: Emanuele Quaranta; Amir Bahreini; Alireza Riasi; Roberto Revelli
• Keywords: Hydraulic head; Water turbine

The Very Low Head turbine (VLHT) is an axial flow developed for heads below 4.5 m and rates up to 30 m3/s. In this work, the state of art, technological advancements scientific gaps were discussed generalized, with a special focus on design, ecological behavior, costs, performance at different flows, rotational speeds. field hydraulic behavior under configurations (e.g. in presence cavitation upstream obstacle) described, aim deriving engineering suggestions. Results tests generalized (fish survival rate more than 90%) by using blade strike model, proposing expeditious method preliminary appraisal impact downstream migrating fish. Despite hundreds installations worldwide, especially existing barriers, some need be better addressed yet, e.g., influence number blades axis inclination efficiency, flow, head speed quantification losses through trash rack above runner.