TITLE:
Experimental Investigation on the Shape and Depth of Local Scour Hole Downstream of the Release Structure
AUTHORS:
Vouchleang Hong, Genguang Zhang, Xinqiang Wang, Anbin Li
KEYWORDS:
Local Scour Downstream, Noncohesive Sediment Bed, Sediment Size, Flow Rate, Flow Pattern, Dangka Hydropower Station
JOURNAL NAME:
World Journal of Engineering and Technology,
Vol.8 No.1,
February
25,
2020
ABSTRACT: Local scour downstream of the release structure is a critical problem to the safe and stable operation of water resources and hydropower engineering. In order to investigate the shape and depth of the scour hole under the equilibrium state of erosion and deposition downstream of an apron, a group of 16 experiments from the hydraulic similarity model test of Dangka Hydropower Stationwas conducted with the non-cohesive sediment of different median particle sizes under different flow rates in this study. The control variable method wastostudy the influence of the flow rate and sediment size on the shape of the scour hole to define the number of experiment times of each test group. The results showed that the plane shape of the scour hole was irregular ellipse or semi-ellipse. The depth and size of the scour hole increased with the increase of the flow rate, and decreased with the increase of the sediment size;the downstream longitudinal slope ratio of the scour hole increased with the increase of the sediment size. The coefficients of the upstream and downstream slope ratio of the local scour hole were 1/2 to 1/6 and about 1/10, respectively.