Effects of distance between the T-shaped spur dikes on flow and scour patterns in 90° bend using the SSIIM model

In this paper, flow and scour patterns resulted from the installation of two T-shaped spur dikes were evaluated in a 90° bend under clear water conditions. The submerged and non-submerged spur dikes were modeled at different locations in the bend using the numerical model. Based on the dikes’ location and submergence, different scour holes on the channel bed were formed. For all models, the maximum secondary flow power occurs at the upstream of the first spur dike and the maximum sedimentation occurs at the end of the inner bank. The maximum scour depth generally occurs at the tip of the first dike wing. The space between the spur dikes should not be more than 5 times of the dike length. In the submerged mode, the maximum scour depth decreased to 22% compared to the non-submerged mode one. Moreover, the location of sedimentation is a little further away from the bend end.