Experimental and Numerical Analysis of Energy Dissipation in Piano Key Weirs with Stepped and Baffled Barriers at Downstream Slop

Document Type : Research Paper

Authors

1 1. Department of Water Science Engineering, Khouzestan Science and Research Branch, Islamic Azad University, Ahvaz, Iran. 2. Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

2 Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

3 Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran

Abstract

Piano Key Weirs (PKWs) are amongst the newly developed long-crested weirs that offer a higher discharge capacity relying on their more extended crest compared to labyrinth weirs of the same width. However, the use of barriers at the outlet of PKWs to increase energy dissipation has received little attention so far. In the present work, stepped and baffled models (with a bench height of 30 mm and baffle dimensions of 30 * 30 mm) were adopted to conduct experiments, and the Flow3D software was used for 3D simulation. Experiments were performed using discharge rate of 10 to 50 lit/s. The results revealed by increasing the discharge rate, the energy dissipation reduces. The energy dissipation rate using the baffles was 8.75% higher than that of the stepped model, and 15.21% higher than that of the case with no barriers.

Keywords

Main Subjects


Akbariyan, A. (2009). Design of Hydraulic Structures Canals. Amidi Publication, Iran. (in Farsi).
Beyrami, M.K. (1999). Water Transfer Structure. Isfahan University of Technology. Isfahan, Iran. (in Farsi).
Blanc, P. and Lempérière, F. (2001). Labyrinth spillways have a promising future. International Journal of Hydropower and Dams, 8,129-131.
Bremer, F.L. and Oertel, M. (2017). Numerical investigation of wall thickness influence on Piano Key Weir discharge coefficients: A preliminary study. Labyrinth and Piano Key Weirs III – PKW 2017. (pp: 101 -108).
Crookston, B.M., Paxson, G.S. and Savage, B.M. (2012). Hydraulic Performance of Labyrinth Weirs for High Headwater Ratios. In: Proceedings of 4th IAHR International Symposium on Hydraulic Structures, 9-11 Feb, Porto, Portugal, pp.1-7.
Delgado, F.G.A., Paulina, M.A. and Camino S.F.G. (2015). Discharge Coefficients Spillways Labyrinth Implementing Hydrodynamic Devices in the upstream side. In: Proceedings of 36th IAHR World Congress. 28 Jun- 3 July, Hague, Netherlands. pp. 1-7.
Erpicum, S. and Machiels, O. (2011). Energy dissipation on a stepped spillway downstream of a Piano key weirs – experimental study. In: Proceedings of International Conference on Labyrinth and Piano Key Weirs, Taylor & Francis Group, London.
Ghanbari R and Heidarnejad, M. (2020). Experimental and numerical analysis of flow hydraulics in triangular and rectangular piano key weirs. Water Science. (pp:1110-4929)
Gharibvand, R. Heidarnejad, M Kashkouli, . H. A. Hasoonizadeh, H. and A. A. Kamanbedast. (2020). Numerical Analysis of Flow Hydraulic in Trapezoidal Labyrinths and Piano Key Weirs. Journal of Water and Soil Science Vol. 24, No. 1, Isfahan University of Technology, Isfahan, Iran. (in Farsi).
 
Henderson, F. M. (1966). Channel controls. Open Channel Flow, Gene Nordby, Macmillan, NY, (pp. 174–175).
Lempérière, F. and Ouamane, A. (2003). The piano keys weir: A new cost-effective solution for spillways. International Journal on Hydropower and Dams, (5),144–149.
Maroosi, M. and Roshan, R. (2015). Analysis and design with FLOW-3D software. Isatis, Fadak, Iran. (in Farsi).
Qanavati, M., Sajjadi, S. M. and Ahadiyan, J. (2016). The effect of block height on flow hydraulic behavior in rectangular piano key weir with baffled outlet key. In: Proceedings of 3rd International Conference on Geographical Science. 3 Nov. Shiraz University. Shiraz, Iran. (in Farsi).
Yarmohammadi, B. (2015). Effect of parapet wall on the inlet submergence in piano key weirs. M. Sc. Thesis. Faculty of Water Engineering. Shahid Chamran University of Ahwaz. Ahvaz, Iran. (in Farsi).