Experimental Iinvestigation of the Effect of theTtriangular Vanes on the Channel Bed Ttopography

Subject Areas : Journal of Water Sciences Research

Nushin Najafi Birgani ¹ , Mahmood Shafai Bejestan ² , Mohammad Bahrami Yarahmadi ³

1 - Former Masters Student, Faculty of Water Science Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
2 - Professor, Faculty of Water Science Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
3 - Assistant Professor, Faculty of Water Science Eng., Shahid Chamran University of Ahvaz, Ahvaz, Iran

Received: 2015-06-23 Accepted : 2015-08-09 Published : 2016-11-01

Keywords: Scour, Spur dike, Triangular vanes, River banks,

Abstract :

The main purpose of this paper was to evaluate the performance of the triangular vanes located on the bed and their effect on the bed topography considering different flow conditions. For this purpose, tests were carried out on a straight flume for different flow conditions (five Froude numbers of 0.18, 0.20, 0.22, 0.24 and 0.26) by installing a series of triangular vanes at a space of 4Le (Le is the effective length of the structure) and considering a 30 degrees angleto the upstream bank. At the end of each test, the bed topography was measured by the laser distance measurer. The results showed that the geometric dimension of the scour hole for the rectangular spur dikes was larger than the triangular vanes. On average, the length and depth of the scour hole for the rectangular spur dikes were 1.3 and 1.5 timesin comparison to the triangular vanes, respectively. In addition, the maximum scour depth considering the triangular vanes was about 40% farther from the bank in comparison to the case with the rectangular spur dikes, that was an advantage for the triangular vanes.