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 ...

throughout history dams have been important structures in water storage. to avoid overtopping, damage, and or failure of a dam, adequate spillway is needed to release excess water from upstream floods. researchers found that spillways have to be made nonlinear in order to reach an economic structure with high performance. a piano key weir is one of the best solutions. piano key weirs are the mo...

Introduction Piano Key weirs (PKWs) are a hydraulically attractive alternative to linear overflow weirs, increasing the unit discharge at the unregulated spillway inlet for similar heads and spillway widths. This advantage, allowing for operation of dam reservoirs on elevated supply levels thus providing an increased retention volume, is a result of the non-linear nature of PKWs being folded ba...

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...

The Piano Key weir (PKW) is a hydraulically attractive alternative to linear overflow weirs, increasing the unit discharge for similar heads and spillway widths. This advantage allows operating dam reservoirs on an increased level and provides thereby an enhanced retention volume. It is a result of the non-linear nature of PKWs being folded back and forth to make repeating cycles or keys. As PK...

Piano Key Weirs (PKWs) are an alternative to linear overflow structures, increasing the unit discharge for similar heads and spillway widths. Thus, they allow to operate reservoirs with elevated supply levels, thereby providing additional storage volume. As they are relatively novel structures, few design criteria are available. Hence, physical model tests of prototypes are required. This study...

The piano key (PK) weir has advanced over the labyrinth to increase discharge capacity. Piano weirs exhibit nonlinear flow behavior and are easy place on existing spillway or newly constructed dam with less base area. Various investigators given equations calculate coefficient for free submerged conditions. study focuses reviewing impacts of PK geometry coefficient, including length height, ups...

Over the past decades, significant advances have been achieved in hydraulic structures for dams, namely water release such as spillway weirs, chutes, and energy dissipators. This editorial presents a brief overview of eleven papers this Special Issue, Advances Spillway Hydraulics: From Theory to Practice, frames them current research trends. Issue explores following topics: inlet structures, tr...