Discharge efficiency of an innovative composite Piano Key Weir
Publication date
2025-03-21
Document type
Forschungsartikel
Author
Organisational unit
Publisher
MDPI
Series or journal
Water
ISSN
Periodical volume
17
Periodical issue
7
Article ID
921
Peer-reviewed
✅
Part of the university bibliography
✅
Language
English
Abstract
Climate-change-induced increases in extreme rainfall events necessitate the enhancement of discharge capacity in aging dam infrastructures. Piano Key Weirs (PKWs), with their compact footprint and efficient discharge performance, present a promising option for improving the discharge efficiency of existing spillways. This study introduces an innovative composite Piano Key Weir (CPKW), which integrates both rectangular and trapezoidal layouts. Numerical simulations were performed to systematically compare the flow field and discharge performance between conventional trapezoidal PKW and composite configurations. Results show that the composite structure significantly improves the discharge capacity of the reference trapezoidal model by up to 16%. This enhancement is primarily attributed to the extended crest length and reduced local submergence, resulting in a more efficient discharge distribution. For the specific composite configurations studied, the optimal key width ratio that effectively balances the inflow efficiency and the adverse effects of nappe interference is found to range between 0.89 and 1.01. Additionally, a relative upstream head of 0.2–0.3 is identified as a critical threshold, beyond which the intense local submergence starts to affect the downstream trapezoidal side-wall section, limiting the contribution of the entire side wall to the total discharge and resulting in decreased overall efficiency.
Description
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
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