The effect of slot on bed topography around the bank attached triangular vane in 90 degree bend

Document Type : Research Paper

Authors

1 shahid chamran university of ahvaz

2 ShahidChamran University of Ahvaz

3 Shahid Chamran University of Ahvaz

Abstract

Although the spur dikes have an appropriate performance to protect the rivers’ bank, these structures are not immune against the local scour around their tips. Recent researches have shown that the bank attached triangular vanes have less scour depth at their tips toward the spur dikes because of their geometrical shape. One of the methods to improve the flow pattern around the structures is creating slots in the structure to reduce the maximum scour depth around the structure’s tips. In order to achieve the purposes of the present study, a rectangular slot (with an opening percentage equal to 10 percent of the effective vane surface and the location of the slot being parallel to the chord) has been created in the bank attached triangular vane. Then the effect of the slot on the bed topography was analyzed at different angles and hydraulic conditions (0.287, 0.304 and 0.322). The research results showed that the average reduction of the maximum scour depth by means of a slot at the angles of 23, 30, 40 and 60 degrees have been 70, 20, 17 and 54 percent, respectively. Also, the created slot in the vane caused the maximum scour depth to be formed away from the outer bank. By increasing the Froude number, the maximum scour depth increased at sample-slotted vanes.

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References

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Iranian Journal of Soil and Water Research
Volume 48, Issue 5
January 2018
Pages 951-961

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