RANCANG BANGUN ALAT UKUR DEBIT MERCU BULAT DENGAN VARIASI KEMIRINGAN HILIR

Abstract

The design of the round crest discharge measuring instrument with variations in the downstream slope is expected to assist students in understanding learning, especially for the round crest discharge measuring instrument material. Starting from hydraulic behavior, measurement accuracy, and making the discharge curve. The method used is to make a model of this rounded discharge measuring instrument by assuming that the Froude number that occurs in the model is the same as the Froude number that occurs in conditions in the field. So that the scale of discharge, time, speed and volume will be able to represent the actual conditions in the field with a scale of length, width and height of 1: 100. The expected results from this design are in the form of a test model of a round cone discharge measuring instrument with variations in downstream slope as a prototype. whose hydraulic behavior can be observed by students with easier understanding such as actual events in the field. The methodology used is to carry out tests in the hydraulics laboratory by varying the discharge starting from Q1, Q2, Q3, Q4, …. Qn, to obtain variations in water level upstream and downstream of the spillway, so that the relationship between discharge and water level upstream and downstream of the spillway can be obtained. Besides that, it is also found that there is a relationship between the variation of discharge flowing through the spillway of the rounded crest with the variation of the downstream slope to the loss of high energy that occurs. From the results of this study, it was found that there was a relationship between discharge and water level upstream, downstream water level, water level above the threshold, and energy loss for round crest spillway with variations in downstream slope. The results of this study indicate that the relationship between water level in the upstream, height above the threshold, and energy loss with discharge for round crests has a similar tendency for various variations of the downstream slope.