This document summarizes an experiment comparing different flow meter types. The experiment used a rota meter, venturi meter, and orifice plate to measure the flow rate of water. Calculations were shown for three trials measuring the actual and theoretical flow rates to determine the discharge coefficient for each meter. Graphs showed the relationship between discharge coefficient and actual flow rate for the venturi meter and orifice plate. The coefficient was generally higher for the venturi meter compared to the orifice plate.
1. Erbil PolytechnicUniversity
Koya Technical Institute
PetroleumTechnology
Operationand Control
Report
Fluid Mechanic Lab.
Test no: (9)
Test name:
(Flow meter Demonstration)
Supervised by:
Karwan A. Ali
Date of Test: 1/02/2018
Date of Submit:08/02/2018
Prepared by: Muhammed Fuad Rashid
3. Aim of the experiment:-
. Compression between different flow meter types.
. Determining the discharge coefficient.
Introduction:-
Fluid mechanics has developed an analytical discipline from the
application of the classical laws of static, dynamics and
thermodynamics, to situation in which fluids can be treated as
continuous media. The particular laws involved are those of
conservation of mass; these laws may be
simplified in an attempt to describe
quantitatively the behavior of the fluids.
The hydraulic bench service module, F1-
10, provides the necessary facilities to
support a comprehensive range of
hydraulic models each of which is
designed to demonstrate a particular
aspect of hydraulic theory. The specific
hydraulic model that is concerned for this
experiment is the flow meter test rig (F1-
21). This consists of venture meter,
variable area meter, and orifice plate installed in a series of
configurations to allow for direct comparisons.
OrificeNozzleVenturi
4. Apparatus:-
The apparatusis discharged to demonstratethree basics
types of flow meter.
-Rota meter
Rota meter:-
A Rota meter with the following characteristics is used to measure
flow rate:
- Plastic measuring tub
5. - Interchangeable stainless steel float
- Max. Flow rate 26 lit/min
The flow rate can be read from the upper edge of the conical
attachment.
Air particles on dirt particles on the float may affect measurement
precision.
To flush the out. Operate the test stand a maximum flow rate first.
To do so, open all cocks fully.
Nozzle and Orifice plate:
The orifice plate housing is made of transparent plastic allowing
visible functioning of the orifice plate. The flow causes a pressure
loss between inlet and outlet. Two tapings allow measurement of
inlet and outlet pressure. This differential pressure (p1-p2) is
proportional to the volume flow rate:
Q=Cd A2
√
2𝑔 (ℎ1−ℎ2)
(1−
𝐴2
2
𝐴1
2
Venturi meter:
The venturi housing is made of transparent plastic allowing visible
functioning of the venturi.
6. The pressure in the venturi inversely propositional to the velocity
in the venturi according to Bernoulli’s law.
Two tapings allow measurement of the inlet pressure and the
pressure at the smallest area.
This differential pressure (p1-p2) is proportional to the volume flow
rate:
Q=Cd A2
√
2𝑔 (ℎ1−ℎ2)
(1−
𝐴2
2
𝐴1
2
Procedure:-
- Arrange the experimentation set-up on the Hydraulic Bench
such that the discharge routs the water into the channel.
- Makes hose connection between Hydraulic Bench and unit
- Connect measurement lines
- Open all valves at pipe section and 6-tube manometer, let the
water flow for 1 minute
- Close flow control valve
7. - Clos drain valve of the 6-tube manometer to vent the
measurement lines
- Clos flow valve of the 6-tube manometer
- Close water inlet
- Disconnect measurement lines
- Open vent and drain valves to discharge level tubes of the 6-tube
manometer
- Close vent and drain valves
- Open flow control valve slowly
- Connect measurement lines again
- Open water inlet slowly
- Adjust the heights of the water in the manometer tubes with the
help of flow control valve until water becomes visible
-Set the flow rate and measurement scale with the inlet and outlet
control valves
-Determine volumetric flow rate. To do so. Use stopwatch to
establish time t required for raising the level in the volumetric tank
of the Hydraulic Bench.
12. Table of calculation:-
Discussion:-
1/Coefficient of discharge is stated as the ratio between the actual
flow discharge and theoretical flow discharge. It is also referred to
as the ratio of mass flow rate at nozzle's discharge edge to the
standard nozzle which enlarges an exact working fluid maintained
at the similar initial conditions and pressures.
It has no dimensions and depends directly on the rate of flow and
velocity of working fluid.
No.
Qact
)/s3
(cm
Rotameter Venture meter Orifice meter
Qrot
(liter/min)
Qact
)/s3
(cm
Qi
)/s3
(cm Cd
Qi
)/s3
(cm Cd
1 225.855 9.9 165 199.58484 1.1316 311.5 0.725056
2 340.3675 16 266.6667 293.5181 1.1584 476.959 0.71362
3 484.4022 22.2 370 410.6096 1.17971 675.2 0.71735
13. It is symbolized by Cd and its value is different for each fluid
depending on the kind of measurement of flow. In nozzle flow
measurement, the efficiency of Cd is higher when compared to the
flow measurement at the orifice. The discharge coefficient is raised
by increasing the overall pressure ratio and reducing the
convergence semi angle. Also, the range of Cd is commonly
superior in supercritical series.
Express the relation of discharge coefficient.
2/
0
50
100
150
200
250
300
350
400
450
500
5 7 9 11 13 15 17 19 21 23 25
Qrot
Qact
