Experimental Study of the Effect of Spur Dike Location and Skimming Wall on Divertion of Flow and Sediment at Lateral Intake

A major problem with which most of the lateral intakes, is accumulation and sediments entering the intake entrance and as a result diversion efficiency is reduced. Sediment control is one of the most important issues in river engineering. To reduce sediment entering the intake entrance several methods of controlling the sediment entering to the intake entrance and the exit of sediments from sediment out let is used. In this study effect of the location, and angle of the spur dike by using skimming wall on the amount of delivered sediment into the lateral intake and intake ratio were tested. Effects of angle variations (30, 45, 60, 90) of spur dike and spur dike location (b, 2b, 2.5b, 3b) on intake ratio and delivered sediment into the intake were investigated (b is the intake width). Results showed that discharge of 60 lit/s, and spur dike with 60 degree angle and 2b distance from the center intake entrance in combination with the skimming wall compared to an angle of 30, 45 and 90 degrees, respectively caused 27, 14 and 12 percent less sediment and 53, 45 and 16 percent superior discharge into the intake divertions. Also by increasing the value of parameter of the ratio of distance of spur dike, to the width of intake, the ratio of flow deviation to the intake for angle of 30°, 45°, 60° and 90°, and ū/uc=1.05 was 5, 13, 2 and 23% respectively, and for ratio of ū/uc=1.08 was 2, 3, 3 and 2% respectively, and for ū/uc=1.11 was 17, 24, 2 and 10 percent increase respectively.