A comparative analysis of the energy dissipation efficiency of various piano key weir types

Abstract

Water levels in main or sub-channels can be controlled and regulated with the help of weirs. Piano key weirs (PKWs), a type of non-linear weir, include side crests, as well as front and back crests. Due to the fact that the PKW is a modern, newly installed infrastructure, several studies addressing the distribution of energy for each type are not yet available. This study examines the amount of energy dissipated for the four primary types, as well as the impact of altering the width ratio and the height ratio. To investigate the effects on energy dissipate, and compare the energy dissipate efficiency of the main types of PKWs, each type of PKW was created with five models using width ratios (W i/W o = 1.25, 1, and 0.8) and height ratios (P/L = 0.11 and 0.078). The energy dissipation depends on type of PKW and decreases as the width ratio increases by 5% and the energy dissipation increases, with the rise in the height ratio by 4%. Due to the overhang effect, type-C is the energy type that dissipates the most, making it the best example of PKW in terms of energy dissipation efficiency. Type-A follows type-C in this respect.

Keywords

• piano key weir
• energy dissipation
• head ratio
• labyrinth weir
• crest length
• residual energy