A numerical study on the behavior of a supercritical flow over piano key side weirs

Document Type : Research Article


1 MSc Student in Civil Engineering, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran

2 Assistant Professor, Faculty of Civil, Water, and Environmental Engineering, Shahid Beheshti University

3 Assistant Professor, Department of Water and Wastewater, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran

4 PhD Student in Civil Engineering, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran


Side weirs are a type of hydraulic structures that can be utilized as a divert structure, controller and distributing flow discharge in Floods and high velocity flows. The flow type over these structures is spatially varied flow with decreasing discharge. Due to use of side weirs for transferring and discharge control in flood flows with high velocities, it is very likely to have a supercritical flow over side weirs. Piano key and labyrinth side weirs are used, where the weir opening length is limited. An advantage of these kind of side weirs is the weir’s effective length relative to its opening. The most carried out studies on the Piano key weirs are limited to the experimental investigations. Considering the limited conditions and high cost of the laboratory works in one hand and recent developments of the numerical models, on the other hand, it is necessary to use the well known fluid dynamics software to simulate the side weir flows. In this study side weirs with different plans have been simulated by FLOW[1]3D. The FLOW-3D numerical model has been calibrated and verified for simulating side weirs using the experimental results. In this study, discharge coefficient for piano key side weirs in supercritical flow is presented. To obtain an optimized shape of the piano key side weirs the different shapes of the keys are also compared. These These results this study can be used for design of the piano key side weirs.


Main Subjects

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