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...

Piano key (PK) weirs are used in a variety of flow control structure applications, including spillway crests and open channel diversion structures. However, to the best authors’ knowledge, structure-specific design guidance for scour mitigation is still needed. To fill this gap systematic experimental campaign was conducted by testing different configurations horizontal aprons with cutoff wall....

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...

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...

In this study an extensive experimental research is carried out to develop a better understanding of the effects of Piano Key (PK) weir geometry on weir flow threshold submergence. Experiments were conducted in a 12 m long, 0.4 m wide and 0.7 m deep rectangular glass wall flume. The main objectives were to investigate the effect of the PK weir geometries including the weir length, weir height, ...

The interest in Piano Key weirs (PKW) was increasing over the past years, both in terms of application and hydraulic research. Several systematic model test series were performed and published so far, originating from different hydraulic laboratories around the world. Therein, the key geometric parameters dominating the hydraulic capacity of PKWs were identified as developed crest length, trans...

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...