Numerical Investigation of Flow and Scour Pattern around T-shaped Spur Dike in a 90 Degree Bend with Live Bed

In this paper، numerical investigation of flow and scour pattern around T-shaped spur dike located in a 90 degree bend with live bed was carried out using SSIIM software. The channel under investigation was a 90 degree channel with radius of curvature of 2. 4 meters، and a T-shaped spur dike was located in a 45 degree position in proportion to the outer bank for determination of flow pattern، with the ratio of wing to web equal to 1. For determination of scour pattern، the ratio of wing to web was considered to range from 0. 25 to 1. 25. Comparison between the results of experimental data and numerical modeling using SSIIM software indicated good agreement between the two. Changes in lateral velocity، profile of the bed due to the effect of the ratio of the wing to the web of the spur dike، 3D velocity components as well as changes in the maximum scour depth were also compared. The results indicated that the amount of scour was minimum for the ratio of wing to web equal to 1. 25. Changes in the maximum scour depth occurred in the range of 1. 29 to 1. 42 times the upstream depth. It was also observed that two vortexes were formed at the downstream side of the spur dike، one clockwise and the other counterclockwise