الفهرس 
Theoretical backgroundOnly 14 pages are availabe for public view
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Abstract
Using non-linear weirs, such as labyrinth weirs and piano key weirs, has recently gained much attention as a practical efficient solution to increase the discharge capacity of spillways. This study evaluates the effect of the piano key weir’s (PKW) shape and types on the flow efficiency for different inlet and outlet keys width ratios (Wi/Wo). The study is performed experimentally and numerically using a CFD model. Three PKW shapes are studied (rectangular, trapezoidal, and triangular). First, the three Type-A shapes were studied experimentally considering Wi/Wo=0.8. The trapezoidal shape has the highest efficiency, while the triangular has the least. The experimental results were used to verify the numerical model, then, the rectangular and trapezoidal shapes were studied numerically for Wi/Wo=1.25. The trapezoidal Type-A PKW with Wi/Wo=1.25 showed the highest flow efficiency of all shapes and Wi/Wo ratios. The rectangular and trapezoidal Type-B PKWs were also studied for Wi/Wo=1.25 and compared to Type-A. The Type-B PKW showed the higher efficiency. The ratio Wi/Wo is the most studied effective parameter on the PKW flow efficiency, followed by the weir’s shape, then its type.