آبشستگي موضعي بستر در پايين دست دريچه كشويي

Bed Scour Downstream of Sluice Gates

In this research, the dynamics of local scour processes is studied in the context of the erosion that takes place downstream from a submerged sluice gate. The most important factors, which affect the local scour processes downstream of the sluice gate are identified and grouped by dimensional analysis to obtain the dimensionless parameters. Experiments were carried out in a horizontal rectangular flume of 9 m long, 0.5 m wide and 0.6 m height. Two gradations of uniform non-cohesive bed material were used for various tailwater depths and flow rate conditions. A total of 22 tests were carried out, each for a period of 12 h. An equilibrium scour condition was not attained over this time period for any of the tests, although a similarity in the bed profiles is observed in the region close to the rigid apron. Based on the experimental data, new dimensionless equations and graphs are presented to determine the shape and dimensions of characteristic lengths of scour hole such as maximum depth of hole and its position, brink scour depth, maximum extension of hole, dune height and its distance from the end of apron. Also, the results are compared with previous researches.