Experimental Study of Local Scour Around Elliptic and Semi-parabolic Groynes in Straight Channels

Abstract

This study was carried out to investigate local scour around curved groynes under different conditions including flow condition, average values of radius of curvature, spacing between groynes, width of groynes, number of groynes, and shapes of groynes. Laboratory works were achieved with 300 runs for elliptic and semi-parabolic groynes models. Three different widths of groynes were adopted as (7, 10, and 13 cm), as well as, using three different number of groyne, single, double and triple. Four different spacing between groynes of (1, 1.5, 2, and 2.5) times of width of groyne were used in the study. The average values of radius of curvature for all adopted shapes used was computed as an additional significant parameters. Dimensional analysis techniques and (MATLAB V.13) program were used to detect the two dimensionless formulas of maximum scour depth for elliptic and semiparabolic groynes. The results gave good determination coefficient of (99) % for both formulas. Generally, the elliptic groyne is the best case of all groynes because gives minimum scour depth, minimum volume of scour and transition of sediments.