Variation of hydraulic parameters with different wing of a T-shape spur dike in bend channels

Abstract

In the present research, by using a numerical model, some analyses were performed on flows around a T-shape spur dike and a support structure located at its upstream under different wing to length ratios of T-shape spur dike in the order of 0.25, 0.50, 0.75 and 1.00. In order to verify numerical model, physical model data were used in presence of a single T shape spur dike. Results from numerical model are desirably in agreement with those of physical one because the regression between both data is 0.86 up to 0.92. In this research, all hydraulic parameters of flows, streamlines and dimensions of flow separation zones were studied in order to select the most practical model. Increased W/L results in 7%–12% increase in the length of flow separation zone and in 2% increase in the width of this zone compared to W/L=0.25.

Keywords

numerical model / wing of T-shape spur dike / support structure / flow pattern

References

[1] GhodsianM, MousaviS K. Scour around a spur dike at a 90° bend [C]. 15th Conference on Scour and Erosion, 20041417

[2] FazliM, GhodsianM, NeyshabouriS S A A. Scour and flow field around a spur dike in a 90° bend [J]. International Journal of Sediment Research, 2008, 23(1): 56-68

[3] DeyS, BarbhuiyaA K. Velocity and turbulence in a scour hole at a vertical-wall abutment [J]. Flow Measurement and Instrumentation, 2006, 17(1): 13-21

[4] GhodsianM, VaghefiM. Experimental study on scour and flow field in a scour hole around a T-shape spur dike in a 90° bend [J]. International Journal of Sediment Research, 2009, 24: 145-158

[5] VaghefiM, GhodsianM, NeyshabouriS S A A. Experimental study on scour around a T-shaped spur dike in a channel bend [J]. Journal of Hydraulic Engineering, 2012, 138(5): 471-474

[6] JiaY, WangS S YCCHE2D: Two-dimensional hydrodynamic and sediment transport model for flows over loose bed [R], 2001, Mississippi, Unsteady Open Channel National Center for Computational Hydroscience and Engineering, University of Mississippi

[7] GiriS, ShimizuY, SurajataB. Laboratory measurement and numerical simulation of flow and turbulence in a meandering-like flume with spurs [J]. Flow Measurement and Instrumentation, 2004, 15: 301-309

[8] AbedJ, RhoadsB, GuneralpI, GarciaM. Flow structure at different stages in a meander bend with bendway weirs [J]. Journal of Hydraulic Engineering, 2008, 134(8): 1052-1063

[9] ZhuZ-W, LiuZ-Qing. CFD prediction of local scour hole around bridge piers [J]. Journal of Central South University, 2012, 19: 273-281

[10] ZandF, MalekiH, SelahshourJ, AbbasC S. Three-dimensional simulation of flow and vortex patterns around the L-shaped impermeable groins at five different angles of the first half of the semicircular arc [J]. Technology Journal of Engineering Applied Science, 2013, 3(9): 1-13

[11] VaghefiM, AhmadiA, FarajiB, JavanM, EghbalzadehA. The Effect of length of a T-shape spur dike on flow patterns in 90° bend channel with support structure [J]. International Journal of Science and Technology, 2014, 3(7): 938-942

[12] VaghefiM, AhmadiA, FarajiB, JavanM, EghbalzadehA. Numerical study of flow patterns around T shape spur dike and support structure [J]. Journal of River Engineering, 2014, 2(5): 1-7

[13] VaghefiM, AhmadiA, FarajiB. The effect of support structure on flow patterns around T-Shape spur dike in 90° bend channel [J]. Arabian Journal for Science and Engineering, 2015, 40(5): 1299-1307

[14] SHUKRY. Flow around bends in an open flume [J]. Transactions of the American Society of Civil Engineers, 1950, 115(1): 751–779.