The difference in flow rate of water that flows into both of the channel was observed. Other than that, the experiment was capable to study the discharge coefficient of fluid flow that determined by calculation of this experiment. The experiment was started as follows the procedures, with the depth of water with different height was tested by recording the time taken to collect 3L of water, which later will be used to calculate the flow rate of the flow. The data obtained were further tabulated by calculating the discharge coefficient, using the equation provided.
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It is usually a device for measuring discharge. A weir is a notch on a larger scale - usually found in rivers. It may be sharp crested but also may have a substantial width in the direction of flow - it is used as both a flow measuring device and a device to raise water levels.
Depending on the weir design, flow may contract as it exits over the top of the weir, and, as with orifices, the point of maximum contraction is called the vena contracta. We will also assume that the velocity through any elemental strip depends only on the depth below the free surface. These are acceptable assumptions for tanks with notches or reservoirs with weirs, but for flows where the velocity approaching the weir is substantial the kinetic energy must be taken into account e.
A General Weir Equation To determine an expression for the theoretical flow through a notch we will consider a horizontal strip of width b and depth h below the free surface, as shown in the figure below. To make further use of this equation we need an expression relating the width of flow across the weir to the depth below the free surface. H is the head over crest in meter. Note that the value of v 1 is obtained by dividing the discharge by the full cross sectional area of the channel itself, not that of the notch.
Deduce an expression for the discharge of water over a right-angled sharp edged V-notch, given that the coefficient of discharge is 0. A rectangular tank 16m by 6m has the same notch in one of its short vertical sides. Determine the time taken for the head, measured from the bottom of the notch, to fall from 15cm to 7.
Experiment #9: Flow Over Weirs
Experiment 9: Flow Over Weirs 1. Introduction A weir is a barrier across the width of a river or stream that alters the characteristics of the flow and usually results in a change in the height of the water level. Several types of weirs are designed for application in natural channels and laboratory flumes. Weirs can be broad-crested, short-crested, or sharp-crested.
Flow Over Notches and Weirs