DETERMINATION OF COEEFFICIENT OF DISCHARCH OVER A TRAPEZOIDAL NOTCH WITH 22∙5° ANGLE OF INCLINATION TO THE VERTICAL
Abstract
ABSTRACT
The accurate determination of discharge over hydraulic structures is essential for the efficient design and operation of open-channel flow systems. This study focuses on evaluating the coefficient of discharge (C_d) for a trapezoidal notch with a side inclination angle of 22.5° to the vertical.
A trapezoidal notch offers improved sensitivity for low-flow measurement compared to rectangular or triangular notches, making it suitable for irrigation channels, laboratory flumes, and small-scale hydraulic systems. In this project, controlled experimental observations were carried out in a hydraulic flume to measure the head of water above the crest for varying discharge rates. The actual discharge obtained through volumetric measurements was compared with theoretical discharge derived from standard weir equations modified for trapezoidal geometry. The coefficient of discharge was then evaluated by relating measured and theoretical values. Results indicate that C_d varies with head and flow conditions, influenced by notch geometry, approach flow, and energy losses. The findings provide a reliable C_d value for the selected notch configuration and contribute useful data for hydraulic measurement applications involving asymmetrical trapezoidal notches.
Full-Text Access Notice
In accordance with the NERD Policy on promoting peer-reviewed publication, public access to the full text of a project, thesis or dissertation is restricted for three years, allowing the author and supervisors sufficient time to pursue peer-reviewed publication.
During this period, researchers with legitimate academic or research purposes may request authorisation directly from the author to enable NERD to release the indexed full texts of the work using the form below.