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This is a powerpoint that shows the principles and calculatons behind the fluid flow apparatus. This uses different types of pipe.
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Experiment 2:
Mechanical Energy Losses due to Straight
Pipes and Fittings in a Viscous Pipe Flow
CAPILI, Mark Lorenz
SAN MIGUEL, John Andre
SILVESTRE, Ces Angelin
VALENCIA, Camille Ann
Introduction
The term pipe flow is used to describe flow through round pipes, ducts, nozzles,
sudden expansion, and contractions,
valves, and other fittings.
Viscous dissipation
http://www.eng.fsu.edu/~alvi/EML4304L/webpage/experiment_5.htm
Introduction
Fluid Flow
Laminar
happens when dealing with small pipes , low flow velocities and with
highly viscous fluids
At low velocities fluids tend to flow without lateral mixing,and adjacent
layers slide past one another
3http://solve.nitk.ac.in/dmdocuments/Chemical/theory_pipes.pdf
Introduction
Fluid Flow
Turbulent
the fluid moves erratically in the form of cross currents and eddies.
happens in general at high flow rates and with larger pipes
4http://solve.nitk.ac.in/dmdocuments/Chemical/theory_pipes.pdf
Introduction
Fluid Flow
Transitional
a mixture of laminar and turbulent flow, with turbulence in the center of
the pipe, and laminar flow near the
edges
5http://solve.nitk.ac.in/dmdocuments/Chemical/theory_pipes.pdf
Introduction
When a gas or liquid flows through a pipe, there is a loss of pressure
frictional loss
loss through fittings
to overcome frictional losses
pump providing power to the fluid
arranging for the fluid to fall under gravity from a higher to a lower elevation (potential energy is reduced)
http://www.eng.fsu.edu/~alvi/EML4304L/webpage/experiment_5.htm
Introduction
Steady-State, Viscous Pipe Flow
Pipe flow in a constant-diameter pipe may be driven by gravity and/or pressure forces
For horizontal pipe flow, gravity has no effect
Pressure difference forces the fluid through the pipe
7
Objectives
The objectives of the experiment are:
To measure the energy losses through the straight pipe and fittings in a pipe flow
system.
To determine the relation of energy losses to the volumetric flow rate in a pipe flow
system from the actual data.
Objectives
To measure the performance of the fluid flow system in the lab by computing the
design calculations with the experimental
data
Materials Needed
10
U-tube Manometer Fluid Flow Apparatus-Pipes
20mm Tee connection
20 mm elbow
25 mm straight pipe
-Pump
-Valves
-Hose
Water and lastly patience
Procedure
Before doing the experiment:
Choose 10 flow rates (100-1000 gal/hr) and
calculate for its Reynolds Number. The flow of the water within the system should
be turbulent (>2100)
Formula to be used: Re = 4q/D
where: = 995.647kg/m3
= 8.222x10-4
Procedure
Close drain valve and pour
water into the feed tank
(3/4 full)
Open all isolating valve
before switching the pump
on
Procedure
Slowly increase the degree
of opening of the entry valve
until bubble formation
becomes minimal
Set the opening of the entry
valve to the designated
degree/flow rate
Procedure
Measure the Pressure head
using the U-tube manometer
and record these pressure for
at least 3 trials
Use another flow rate
setting
Data
Flow Rate gal/hr RM mmHg
o 20mm Tee connection:
Flow Rate 1000 940 900 860 840
Trial 1 25 25 20.325 15.625 15.625
Trial 2 26.5625 25 31.875 18.75 15.625
Flow Rate 800 760 740 700 680
Trial 1 14.0625 14.0625 9.375 9.375 4.6875
Trial 2 14.0625 12.5 10.9375 9.375 6.25
Data
Flow Rate gal/hr RM mmHg
o 20mm elbow:
Flow Rate 520 500 440 420 380
Trial 1 40.625 34.375 32.8125 31.25 28.125
Trial 2 42.5 35.9375 32.8125 29.6875 25
Flow Rate 340 300 260 220 180
Trial 1 21.875 12.5 8.3 6.2 4.6875
Trial 2 18.75 13.5625 10.9375 6.25 3.90625
Data
Flow Rate gal/hr RM mmHg
o 25mm Straight Pipe:
Flow Rate 520 500 440 420 380
Trial 1 68.75 64.0625 56.25 53.125 46.875
Trial 2 65.625 65.6 57.8125 51.5625 48.4375
Flow Rate 340 300 260 220 180
Trial 1 37.5 31.25 28.125 21.875 20.3125
Trial 2 35.156 33.6 26.5625 24.22 22.66
Sample Calculation
Formula to be used: Re = 4q/D
where: = 995.647kg/m3
= 8.222x10-4Pas
Data chosen: 180 gal/hr at 25mm straight pipe
=4(180
)(
1 3600 )(
3.7851 )(
13
1000 )(995.6473
)
(8.2222 1042
)(25)(1
1000)
Re=11671.71 >2100
Sample Calculation
Manometer Reading
in mmHg
= 92 78
= 14
Rm
Recommendation
Start the pump only when the water level inthe tank is almost full.
Make sure that the U-tube manometer hasno water added into it
Place the manometer in the ground level
Timing and Patience is a key factor
Slowly adjust the flow rates and operateonly in a set of range.
Recommendation
Keep all unused valves closed.
Hoses that connect the pipe andmanometer must be observed carefully
and bending must be avoided.
Bring plastic cover or paper.
Be sure that the one who measuresdoesnt have eye problems
Extra clothes is a must!
Always keep your workplace
clean