This paper focuses on Piano Key Weirs (PKWs) as an effective solution for improving the discharge capacity of spillway systems. The flow behavior in inlet and outlet keys is experimentally studied to analyze PKWs with different plan shapes (i.e., rectangular, trapezoidal, triangular). results show that keys, aeration regimes extend higher values headwater ratios (Ho/P) by increasing length magn...

The piano key weir (PKW) is a type of nonlinear control structure that can be used to increase unit discharge over linear overflow weir geometries, particularly when the weir footprint area is restricted To predict the outflow passing over a piano key weir, the discharge coefficient in the general equation of weir needs to be known. This paper presents the results of laboratory model testing of...

One of the most important conflicts that shaft spillways have to deal with is vortex formation. This phenomenon leads to some unfavorable effects such as vibration in the body of structures, air entrainment and reduced overflow capacity of the spillway. Among all solutions for disrupted vortex formation, an innovative one called circular piano-key spillway, based upon piano key weir principles ...

In the scope of dam rehabilitation to manage floods increase or storage, Piano Key Weir is a good solution for concrete dams. The efficiency Weirs now well demonstrated through various experimental studies. Until most prototypes close Type A using symmetrical up- and downstream overhangs structural reasons. position influences inlet outlet key slopes cross section as side crest length influence...

Abstract Energy dissipation is one of the important issues in piano key weirs (PKWs). Excessive energy at weir's toe can cause scouring. In previous studies, arced (APKWs) has not been investigated. this experimental study, effect weir height as well and arrangement baffles located on outlet slope amount dissipated were examined trapezoidal (TPKWs) APKWs. Experiments performed models with two t...