Measurement of Flow Rate
Fluid Mechanics
Year 1
BEng Mechanical Engineering
Fluid Mechanics E1
1
,Abstract
Fluid flow rates in tubes and other process systems must be measured accurately in order to be
used in the industry, particularly the chemical sector. Inlet Cone, Pitot-tube traverse,
Venturimeter, and Orifice Plate are the four flow rate measurement techniques covered in this
paper.
Based on Bernoulli and the continuity equation of fluid flow, all of these devices provide
obstruction to the flow, which results in a pressure drop. This pressure drop is quantified and
correlated with the fluid's flow rate.
The experiment revealed good agreement between the Venturimeter and Orifice Plate devices'
measurements of flow rates. At 0.32 kg/s, the mass flow rate was nearly constant (for two
decimal places accuracy). Particularly when the damper was only partially closed, the flow rate
as measured by the pitot tube was marginally lower. The sixteen measurements made revealed
some differences. As a result, some human error is predicted in the lab results.
Both times the damper was opened, the input cone's discharge coefficient, which was 0.74 and
0.76, remained constant. This is to be expected given that the experiment's cone's dimensions
and flow characteristics stayed constant.
The experiment enabled comprehension of the Bernoulli's and continuity principles and aided
in comprehending how to calculate mass flow rate in respect to actual laboratory conditions.
2
, Table of Contents
Abstract ..................................................................................................................................................... 1
1.0 Introduction ...................................................................................................................................... 4
1.1 Aims and Objectives.........................................................................................................4
1.2 Introduction on flow measurements ...............................................................................4
2.0 Theory ............................................................................................................................................... 5
2.1 Bernoulli’s Equation .........................................................................................................5
2.2 Pitot Tube .........................................................................................................................6
2.2 Inlet Cone .........................................................................................................................6
2.3 Venturimeter ...................................................................................................................6
2.4 Orifice Plate......................................................................................................................6
3.0 Apparatus .......................................................................................................................................... 7
3.1 Inlet Cone .........................................................................................................................7
3.2 Fan ....................................................................................................................................7
3.4 Pitot-Tube ........................................................................................................................7
3.5 Venturimeter ...................................................................................................................7
3.6 Orifice plate......................................................................................................................7
3.7 Damper ............................................................................................................................7
4.0 Test Procedure .................................................................................................................................. 8
4.1 Procedure Steps ...............................................................................................................8
5.0 Result................................................................................................................................................... 9
5.2.1 Pitot-Tube ............................................................................................................................. 9
5.2.2 Venturimeter ...................................................................................................................... 10
5.2.3 Orifice Plate ........................................................................................................................ 10
5.2.2 Inlet Cone ............................................................................................................................ 11
6.0 Discussion .......................................................................................................................................... 12
7.0 Conclusions ....................................................................................................................................... 13
Bibliography ............................................................................................................................................ 14
Appendix A - Figures ............................................................................................................................... 15
Appendix B - Tables ................................................................................................................................. 17
3
Fluid Mechanics
Year 1
BEng Mechanical Engineering
Fluid Mechanics E1
1
,Abstract
Fluid flow rates in tubes and other process systems must be measured accurately in order to be
used in the industry, particularly the chemical sector. Inlet Cone, Pitot-tube traverse,
Venturimeter, and Orifice Plate are the four flow rate measurement techniques covered in this
paper.
Based on Bernoulli and the continuity equation of fluid flow, all of these devices provide
obstruction to the flow, which results in a pressure drop. This pressure drop is quantified and
correlated with the fluid's flow rate.
The experiment revealed good agreement between the Venturimeter and Orifice Plate devices'
measurements of flow rates. At 0.32 kg/s, the mass flow rate was nearly constant (for two
decimal places accuracy). Particularly when the damper was only partially closed, the flow rate
as measured by the pitot tube was marginally lower. The sixteen measurements made revealed
some differences. As a result, some human error is predicted in the lab results.
Both times the damper was opened, the input cone's discharge coefficient, which was 0.74 and
0.76, remained constant. This is to be expected given that the experiment's cone's dimensions
and flow characteristics stayed constant.
The experiment enabled comprehension of the Bernoulli's and continuity principles and aided
in comprehending how to calculate mass flow rate in respect to actual laboratory conditions.
2
, Table of Contents
Abstract ..................................................................................................................................................... 1
1.0 Introduction ...................................................................................................................................... 4
1.1 Aims and Objectives.........................................................................................................4
1.2 Introduction on flow measurements ...............................................................................4
2.0 Theory ............................................................................................................................................... 5
2.1 Bernoulli’s Equation .........................................................................................................5
2.2 Pitot Tube .........................................................................................................................6
2.2 Inlet Cone .........................................................................................................................6
2.3 Venturimeter ...................................................................................................................6
2.4 Orifice Plate......................................................................................................................6
3.0 Apparatus .......................................................................................................................................... 7
3.1 Inlet Cone .........................................................................................................................7
3.2 Fan ....................................................................................................................................7
3.4 Pitot-Tube ........................................................................................................................7
3.5 Venturimeter ...................................................................................................................7
3.6 Orifice plate......................................................................................................................7
3.7 Damper ............................................................................................................................7
4.0 Test Procedure .................................................................................................................................. 8
4.1 Procedure Steps ...............................................................................................................8
5.0 Result................................................................................................................................................... 9
5.2.1 Pitot-Tube ............................................................................................................................. 9
5.2.2 Venturimeter ...................................................................................................................... 10
5.2.3 Orifice Plate ........................................................................................................................ 10
5.2.2 Inlet Cone ............................................................................................................................ 11
6.0 Discussion .......................................................................................................................................... 12
7.0 Conclusions ....................................................................................................................................... 13
Bibliography ............................................................................................................................................ 14
Appendix A - Figures ............................................................................................................................... 15
Appendix B - Tables ................................................................................................................................. 17
3
