Applied Analysis of Piano Key Weir (PKW) Structures as a Diversion Dam

Document Type : Research Article


Department of Water Structure, Faculty of Water Science Engineering, Shahid Chamran University, Ahvaz, Iran.


In the present study, the hydraulic capability of piano key weir (PKW) was investigated utilizing the physical model. Because of decrease in water surface at dry seasons, these structure increases upstream head water. In addition, they have an appropriate discharge coefficient at the flood. To achieve the purposes of this research, two models of PKW were built with the ratio of height to a cycle width (P/Wu) equal to 1.33 (model 1) and 0.5 (model 2). The positive and negative slopes of parapet walls were considered with slopes 3, 5.5 and 8o rather than direction of flow. The results showed that model 2 has a more capability at the increased water surface in the low discharges. Moreover, model 1 has a suitable discharge coefficient at the higher discharge. Results obtained from analysis showed that H/R parameters have a significantly influence on the discharge coefficient when this weir is not submersible or there is a low head after fully submergence. The correlation of discharge coefficient equation after and before fully submergence of weir was 0.976 and 0.973, respectively.


Main Subjects

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