Numerical investigation of flow behavior over arced trapezoidal piano key weirs

Document Type : Research Article

Authors

1 Shahrood University of Technology

2 Shahrood university of Technology

Abstract

Weir is one of the most common artificial hydraulic structures that are used to measure flow in canals, divert flow, store water, change the flow regime in canals, and control floods during rainfall. One of the most important advantages of piano key weirs compared to linear weirs is the improvement of flow transfer capacity by increasing the length of the crest and as a result, increasing the length of the water passage in a fixed width of the construction without increasing the upstream water load. The purpose of this research is to numerically model the flow and investigate the effect of simultaneous changes in the number of cycles and the angle of the weir on the flow coefficient by trying to keep the total length of the weir crest and other geometric parameters constant for all models. After the investigations, it was found that increasing the weir angle of the piano key at a fixed length for all models increases the discharge coefficient, while increasing the number of cycles at a fixed length for all models due to the reduction of the inlet key water tank area, increasing the contraction of the current streamlines and then intensifying the local submergence in the outlet key, the current permeability coefficient will decrease significantly. Among all the weirs modeled in this research, the ATPK135-2 is known as the best model and was able to increase the discharge coefficient by 47% compared to the linear state (without curvature).

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References

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Amirkabir Journal of Civil Engineering
Volume 55, Issue 11
February 2024
Pages 2285-2310

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