Experimental Study of Height and Surface Roughness Effects of Crump Weirs on Over Flow Characteristics

Abstract

In the different fields of hydraulics, environmental, irrigation, and chemical engineering, weirs are the most widely used hydraulic structures as flow measuring and flow control devices in open Channels. Conventional rectangular, triangular, and trapezoidal weirs are among the oldest weirs. The concern of this paper is to study the effect of height and surface roughness(that coming from different of construction materials)of crump weirs on discharge coefficients (Cd) under different flow conditions.This work was conducted in experimental flume by using three sizes of crump weir and three types of surface roughness. The obtained results show that Cd values will increase with increasing flow rate as well as with decreasing in crump height; an increase in surface roughness of crump weir can makes great reduction in Cd value. (The water level to weir height) h/P effect on Cd values increase with increasing in crump weir height. An empirical relation was obtained to estimate the coefficient of discharge Cd under different height and surface roughness of crump weirs

Keywords

weir, roughness, surface, flow