Study of hydraulic characteristics of trapezoidal piano key side weir using different approaches

Abstract Side weirs are widely used in hydraulic engineering applications. The studies on the subject have been generally focused classical and labyrinth side weirs. However, same is not true for piano key (PKSW) a straight channel. weir (PKW) has high discharge capacity compared with In this study, characteristics of trapezoidal (TPKSW) channels were investigated experimentally. all experiments, nine TPKSW models studied extensively using De Marchi, Domínguez Schmidt approaches subcritical flow regime, Froude number range 0.12 < F1 0.87. results show that provides better performance to traditional rectangular triangular Specifically, 0.4 condition, efficiencies close each other. A more efficient than at larger numbers. 2.9 12 times higher weir. Scatter diagrams obtained CPW numbers various available literature. diagram generated by Marchi approach much less scattering, approaches. It determined TPKSWs an effective type lateral flows. Lastly, empirical equation was coefficient, which good agreement experimental data.