Effect of the shape and type of piano key weirs on the flow efficiency

Abstract

This study evaluates the effect of the piano key weir’s (PKW) shape and type 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, three Type-A shapes were studied experimentally considering Wi/Wo = 0.8. The trapezoidal shape had the highest efficiency, while the triangular had 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 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.

Keywords

• Piano key weir (PKW)
• Flow efficiency
• CFD Ansys-Fluent
• Coefficient of discharge
• Shape of the weir