Venturi meter tech memeo-science
Venturi meter tech memeo-science
ExperimentH1-VenturiMeter
Aventuri meter is a device for the measurement offlow. Operatingon the same principles as an orificeplate,the venturi meter induces a smallerhead loss.It is, however,mechanicallymore complex, as show in Figure H2.1.
FigureH1.1:TypicalVenturiMeter
Purpose: The purpose of this experiment is to illustrate the use of the venturi meter inmeasuring the flow of an incompressible liquid througha pipe.In addition, bymeasuring the pressure at various points along theventuri meter, the energy lossesthrough the venturi meter can be determined.
Equipment: The equipment used in this experimentincludes:
- Hydraulic bench with supply tank, pump,and weigh
- Venturi meter apparatus with manome
- Stop
Procedure:
- Place the venturi meter apparatus on the hydraulic bench
- Connect the upstreamside of the apparatus tothe bench supply valve with plastic
- Connect the downstream end ofthe apparatus toa plastic hose that is directed througha hole in the top of the bench to the weigh
- Set the apparatus flow control and bench supplyvalve to full open Control flowrate by turning only the knob on the venturi meter apparatus, not the flow knob on hydraulic bench.
- MAKE SURE THATTHE AIRPURGE VALVE ON THE TOP OF THE VENTURI APPARATUS IS
- Clear all air bubbles fromthe manometer
- Release the air purge valve to allow the water to rise approximately one-half way up the manometer
- Close the purge valv
- Turn the venturi apparatus valve to obtain full After placing weights on support, time how long it takes for the arm attached to tank in hydraulic bench to hit gate in closed position. This data will be used to compute your direct measurement of flowrate.
- Observe the liquid levelsin the manometer tubes tomake sure that the purge valve is fully sealed. Ifthe valve is not sealed,there will be a steady rise in the liquid levels inthe manome
- Read all manometer lev
- Adjust flowrate forat least 3more runs and repeat Steps 13 and
Data required:
- Apparatusmeasurements
- Tube diameters, mm= 26.00 (inlet, 23.20, 18.40, 16.00 (throat), 16.80, 18.47, 20.16,
21.84, 23.53, 25.24, 26.00 (outlet).
- Weight of water collectedand elapsed tim
- Manometer
Analysis:
Plot the following relationships on rectilinearpaper:
| Independent Variable
(X-axis) |
Dependent Variable
(Y-axis) |
| 1. Distance along the venturi meter |
Measuredandidealized pressure distribution
(h −h)/v2 /2g
n 1 |
| 2. (h −h )1/2
1 2 |
Actualflowrate, Qact |
| 3. Theoretical flowrateQn+1 |
Qact/Qtheor(K) |
In addition, compare the value ofK based on theexperimental data to that in the literature (Figure 13.12 in Robeson & Crowe).
Discussion:
- Differences between theory and experimental results, based on plots generated in the table above.
- Using value of K you have obtained by experiment, determine throat diameter of venturi meter that would measure a flow of 0.4 m3/s in a pipe of 0.6 m diameter with differential head of 0.8 m.
- Sources of error.
CE328HydraulicsandEnvironmental LaboratoryExperiment H2: Venturi Meter
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Trial No. |
Weight of Water |
Elapsed Time |
Flowrate (cfs) |
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| IdealizedPressure Distribution along Venturi Meter |
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⎝ 1⎠
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Piezometer Tube No. |
Flowrate:
(mm) |
Trial No.
(mm) |
hn −h1v2 |
Flowrate:
(mm) |
Trial No.
(mm) |
hn −h1v2 |
Flowrate:
(mm) |
Trial No.
(mm) |
hn −h1v2 |
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ExperimentH2: Venturi Meter (con’t.)
hn hn−h1 2
hn hn−h1 2
hn hn−
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