Flow Characteristics Investigation On Trapezoidal Weir Using FLOW 3D

Abstract

Weir is a building that is formed to change the nature of river flow to accommodate irrigation needs. The main purpose of a weir is to raise the river water level, drain the channel through the intake channel, allow water to be tapped, control all flow, etc. If a flow experiences a large shock, it will cause a hydraulic jump resulting in a transition of flow from supercritical to subcritical. The analysis can be performed, it was done using the Computational Fluids Dynamics (CFD) software, FLOW-3D. To model the 3-D weir used in this FLOW-3d, AutoCAD is used and finally, Flow Sight will be used to display visualization results such as graphics and videos. This paper investigates the Froude number and depth-averaged velocity on the trapezoidal weir. Moreover, the numerical modelling of trapezoidal weirs has been compared with the experimental result and numerical modelling of other types of weirs. The results show that the Froude number is proportional to the average velocity of this depth because the Froude number increases with the increase in the average velocity. There is a difference with the flow that flows after the weir, in a trapezoidal weir the Froude number decrease slightly but after that, it increases again downstream.