Numerical Study of the Effect of Radius of Curvature on the Flow Pattern Around a T-Shaped Spur Dike Located at a 90 Degree Bend with a Rigid Bed

Subject Areas : Subjects

M. واقفی ¹ (استادیار سازه های هیدرولیکی، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه خلیج فارس، بوشهر)
M. GH ² (استاد هیدرولیک، دانشکده مهندسی عمران و محیط زیست، دانشگاه تربیت مدرس، تهران)
B. سلیمانی ³ (فارغ التحصیل کارشناسی ارشد، گروه مهندسی عمران، دانشگاه آزاد اسلامی، بوشهر)
M. اکبری ⁴ (دانشجوی کارشناسی ارشد، سازه های هیدرولیکی، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه خلیج فارس، بوشهر *- نویسنده مسوول مقاله: [e-mail])

Received: 2014-10-01 Accepted : 2014-10-01 Published : 2014-11-22

Keywords: T-shape spur dike, flow pattern, radius of curvature, 90 degree bend, flow 3D,

Abstract :

Spur dikes are rigid hydraulic structures built out from a river bank used in order to protect it from the rushing water. These structures also play significant roles in changing the river's depth, in causing sedimentation, in controlling erosion along the river, and in dealing with some environmental issue. In this paper, the flow pattern around a T-shaped spur dike at a 45 degree position located in a 90 degree bend with a rigid bed has been investigated, while the radius of curvature changes, but geometry of the spur dike (l/L = 1) and a discharge of 25 liters per second  around it remain constant. The results indicate that as the radius of curvature increases, the vortex downstream becomes smaller in a way that when the central radius increases three times of the channel width, the vortex length decreases three times that of the spur dike length, and its radius reduces as much as 0.9 fold of the spur dike length. The roles of the radius of curvature and the analyses of the results have been discussed in this paper.