بررسي آزمايشگاهي ابعاد حفره آبشستگي پايين دست كالورت لوله اي

Experimental Investigation On Scour Hole Geometry Downstream Of Pipe Culvert

Scouring is a two phase flow and has been experimentally studied. Culverts are used to transfer the flow from one side of roads or banks to the other side. This experimental work is conducted to study the scouring down stream of a pipe culvert. The scour hole properties is a function of various parameters like: discharge, height of drop, tail water depth, diameter of the pipe and sediment size. In this study, variations of scour hole dimensions, and changes of the ridge caused by scouring were correlated to: pipe diameter, drop height, densimetric Fronde number and tail water depth. It was observed that depth and width of the scour hole and the height of the ridge increase with the increasing the pipe diameter, but the length of scour hole decrease. Moreover, it was observed that increasing the tail water depth, width and depth of the scour hole decrease, but the length of scour hole and height of the ridge increases. In addition, with increasing the drop height, depth and width of scour hole and height of the ridge increase, but length of scouring hole decrease. The ratio of the scour hole dimensions and the height of the ridge to the drop height was related to TwID (tail water to pipe diameter ratio), SN (densimetric Froude number) and Hc/D (drop height to pipe diameter ratio).