Investigation of maximum scour depth in compound structure of weir-gate due to gate opening using FLOW-3D numerical model
Subject Areas : hydraulic structures
behnam namadian
1
(Master of Civil Engineering, Majoring in Water Engineering and Hydraulic Structures, Faculty of Engineering, Shahid Madani University of Azerbaijan, Tabriz, Iran.)
Ebrahim Asadi
2
(Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Shahid Madani University of Azerbaijan, Tabriz, Iran.)
Keywords: Scour, Numerical model, Flow-3D, Composite Structure, weir-gate,
Abstract :
The flow and drainage structures are widely used in irrigation and drainage networks due to their simple and relatively precise relationships. The flow causes the return of water and consequently increases the flow cross section and decreases the speed and also creates suitable conditions for sediment deposition and waste in the water, which is considered as a disadvantage of this structure. With the accumulation of sediments upstream, the flow conditions are changed and the accuracy of the extracted relationships is reduced to estimate the discharge. By combining the flow and valve, it is possible to reduce the problems and disadvantages of using each one alone and at the same time use their advantages so that the depositable materials behind the flow and accumulator in the hatch entrance pass through the substructure. Rhine, the combined behavior of spillway flow with jet out from under the hatch, creates different conditions downstream of such structures and causes scour changes downstream of this. The overall purpose of this study was to investigate the effect of valve opening rate on scouring rate in the case of discharge through the combined structure, upstream head height using flow-3D numerical model.The results show that by reducing the opening of the valve, the height of the water on the structure increases and causes the scour depth to increase. Also, by increasing the flow rate over the spillway and under the valve and the height of the upstream water, the maximum scour depth increases.
_||_