<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>In this paper, the scour downstream of a trapezoidal Piano key weir (PKW) is investigated under free and submerged flow conditions. For this purpose, an experimental model was used in a laboratory channel with a length of 10 m, width of 0.75 m, and height of 0.8 m at various discharges and tailwater depths. The results showed an increase and decrease in the maximum scour depth with an increase in the discharge and submergence ratio, respectively. In addition, increasing the particle Froude number enhanced the geometric features of the scour hole downstream of the PKW. The rate of bed changes slowed down over time. The average values of maximum scour depth, the distance of the maximum scour depth from the weir toe, maximum scour hole length and weir toe scour depth increased in the free flow compared to the submerged flow. The scour hole volume and scour hole area in the submerged flow were less compared to the free flow. The average maximum level of the sedimentary ridge in the free flow is less than the submerged flow. New equations for calculating the geometric characteristics of the scour hole downstream of the trapezoidal PKW are presented with acceptable accuracy.</p>
</abstract>

In this paper, the scour downstream of a trapezoidal Piano key weir (PKW) is investigated under free and submerged flow conditions. For this purpose, an experimental model was used in a laboratory channel with a length of 10 m, width of 0.75 m, and height of 0.8 m at various discharges and tailwater depths. The results showed an increase and decrease in the maximum scour depth with an increase in the discharge and submergence ratio, respectively. In addition, increasing the particle Froude number enhanced the geometric features of the scour hole downstream of the PKW. The rate of bed changes slowed down over time. The average values of maximum scour depth, the distance of the maximum scour depth from the weir toe, maximum scour hole length and weir toe scour depth increased in the free flow compared to the submerged flow. The scour hole volume and scour hole area in the submerged flow were less compared to the free flow. The average maximum level of the sedimentary ridge in the free flow is less than the submerged flow. New equations for calculating the geometric characteristics of the scour hole downstream of the trapezoidal PKW are presented with acceptable accuracy.

Experimental investigation of scour downstream of a type A trapezoidal piano key weir under free and submerged flow conditions

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

In this paper, the scour downstream of a trapezoidal Piano key weir (PKW) is investigated under free and submerged flow conditions. For this purpose, an...

Experimental investigation of scour downstream of a type A trapezoidal piano key weir under free and submerged flow conditions

Published Online: Feb 08, 2024

Page range: 34 - 48

Received: Apr 27, 2023

Accepted: Oct 18, 2023

DOI: https://doi.org/10.2478/johh-2023-0041

Keywords
Free flow, Particle Froude number, Piano key weir, Scouring, Submerged flow

© 2023 Elnaz Bodaghi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Experimental investigation of scour downstream of a type A trapezoidal piano key weir under free and submerged flow conditions

Published Online: Feb 08, 2024

Page range: 34 - 48

Received: Apr 27, 2023

Accepted: Oct 18, 2023

DOI: https://doi.org/10.2478/johh-2023-0041

KeywordsFree flow, Particle Froude number, Piano key weir, Scouring, Submerged flow

© 2023 Elnaz Bodaghi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Free flow, Particle Froude number, Piano key weir, Scouring, Submerged flow